Fred C. Adams, University of Michigan PLANET MIGRATION: The effects of Disk Torques, Planet-Planet Scattering, and Turbulent Fluctuations Abstract: This talk describes theoretical studies of planet migration in star/disk systems. These dynamical systems are highly chaotic, so that multiple realizations of the calculations must be performed and the results must be presented in terms of the distributions of possible orbital elements. During the planet formation epoch, both residual circumstellar disks and multiple planets are expected to be present. Disk torques and planet-planet scattering change the orbital elements of migrating planets in complementary ways. Disks are effective at moving planets inward (changing the semi-major axes), whereas planet-planet scattering is effective at increasing the orbital eccentricities. The interplay between these two effects leads to a wide variety of possible outcomes. This model of migration -- driven by tidal interactions with a disk and by dynamical scattering from other planets -- naturally produces the observed range of semi-major axis and eccentricity. Next, we show how type I migration is affected by turbulent density fluctuations in the disk. For type I migration, the planet does not clear a gap in the disk and its secular motion is driven by torques generated by the wakes it creates in the surrounding disk fluid. MHD turbulence creates additional density perturbations that gravitationally interact with the planet and can dominate the torques produced by the migration mechanism itself. Conventional type I migration can be readily overwhelmed by turbulent perturbations and hence the usual description of type I migration must be modified wherever the magnetorotational instability is active. The migrating planet does not follow a smooth inward trend, but rather exhibits a random walk through phase space. MHD turbulence thus alters the time scales for type I planet migration and the time scales display a full distribution of values. _____________________________________________________________________ Suzanne Aigrain (1), Simon Hodgkin (1), Jonathan Irwin(1), Mike Irwin (1) (1) IoA, Cambridge, UK Searching for planetary transits and rotation periods in the Orion Nebula Cluster We have recently started monitoring the Orion Nebula Cluster (ONC) using the Wide Field Camera (WFC) on the 2.5m Isaac Newton Telescope (INT) on La Palma. The primary aim of this survey is to search for transits by close-in giant exo-planets orbiting very young stars (ONC age: 1-3 Myr). Detecting such planets would provide very important constraints for planet formation and early evolution scenarios. Additional science goals include searching for low-mass eclipsing binaries and measuring rotation periods for hundreds of low- and very low-mass stars. The intrinsic variability of young low mass stars, which exhibit both aperiodic and periodic variations at the 10% level on timescales of a few days and less, makes the detection of planetary transits in the ONC even more challenging than it is around older stars. We will discuss techniques to characterise this variability and to disentangle it from potential transit signals. Preliminary results from our first two observing runs will be presented. Finally, we will discuss potential applications of these techniques to other ground- and space based transit searches. Suzanne Aigrain (1), Mike Irwin (1), Gerry Gilmore (1), Fabio Favata (2), Claire Moutou (3) and the CoRoT Exo-planet Working Group (1) IoA, Cambridge, UK (2) ESA/ESTEC, Noordwijk, The Netherlands (3) OAMP, Marseille, France Prospects for detecting Hot Earths with COROT CoRoT (Convection, Rotation and Transits) is a small CNES/ESA mission with a launch date of June 2006. It will carry out high precision, high time sampling photometry of 10,000s of stars for periods up to 5 months. Its two primary science goals are to detect exo-planets via the transit method down to terrestrial masses, and to perform asteroseismology of stars across the HR diagram. Recently, the CoRoT Exo-planet Working Group carried out a blind transit detection exercise, which aimed to test several light curve detrending and transit search methods and compare their effectiveness on realsitic simulated CoRoT light curves. I will discuss the results of this exercise and the limits for planet detectability with CoRoT that can be inferred from it, particularly in the close-in (a < 0.1 AU), terrestrial (R_p < 2.2 R_Earth) regime. _____________________________________________________________________ Jeremy Bailey, Australian Centre for Astrobiology, Macquarie University, Sydney, Australia Planet Detection from Dome C in Antarctica Dome C (Concordia Station) lies at an altitude of 3250m on the Antarctic Plateau. The cold, dry, stable air at this location makes it an outstanding location for astronomical observation. The site offers particular advantages for a number of planet detection techniques. As a photometric site it provides low scinitillation, stable transparency and the possibility of continuous 24 hour coverage, making it the ideal place for transit detection and follow-up studies. The excellent seeing and low winds make it also an ideal site for the construction of an extremely large telescope for direct imaging of extrasolar planets. ____________________________________________________________________ John Bally Department of Astrophysical and Planetary Sciences Center for Astrophysics and Space Astronomy Center for Astrobiology University of Colorado, Boulder Planet Formation in OB Associations The majority (~90%) of all stars in the sky form in dense clusters containing from tens to many thousands of stars. Most of these clusters are transient gravitationally unbound entities which expand and dissolve on a time-scale of several million years, comparable to the time required for planet formation. In these environments, intense UV radiation, powerful stellar winds, and supernova explosions effect protoplanetary disk evolution. There is emerging evidence that our Solar system formed in just such an environment. Contrary to previous ideas, recent work suggests that OB associations and HII regions may be ideal sites for planetary system birth. The inner parts of disks (to radii of tens of AU from the central star) can survive photo-erosion for many millions of years, longer than the survival time of unbound clusters and their most massive stars. Furthermore, the photo-erosion of light gases increases the concentration of heavy elements, rocks, and ices, possibly to the point of gravitational instability. Thus, UV radiation may facilitate planetesimal formation. Supernovae in OB associations can supply the short-lived nuclei such as 60Fe and 26Al known to be injected into our Solar System within a few million years of its birth. I will present new ACS observations of young disks in the Orion Nebula, the nearest actively forming OB association, and review some of the consequences of planet formation in Orion-like environments. _____________________________________________________________________ Gaspar Bakos (Harvard CfA) Exoplanet search with the HAT Network We give an overview of the current status of the HATNet, a system consisting of six fully automated, wide (8x8 deg) field, fast-focal ratio telescopes, aiming for the discovery of transiting planets around bright stars. A secondary goal is to monitor selected areas of the sky for variability. HATnet utilizes two sites that are separated in longitude: the Fred Lawrence Whipple Observatory (FLWO) in Arizona with four, and the Submillimeter Array (SMA) site atop Mauna Kea, Hawaii with two HAT telescopes, respectively. HATNet has been built up gradually since the Spring of 2003, and currently all six units are operational. The telescopes are connected to each other via the Internet in an automated way, and field observations are performed by the two sites in an optimal way to ensure maximum coverage of the light-curves. In the past 1.5 years we have accumulated some 77,000 science frames at 5 minute time resolution on 15 selected fields. We processed the 1.5Tb data, and derived light-curves for 100,000 stars, with 25,000 reaching precision better than 1%. The data was searched for transits by the BLS algorithm, and 120 potential transit candidates were found. These were in turn followed up by "rejection mode spectroscopy" using the CfA Digital Speedometers at Oak Ridge Observatory and FLWO, or by follow-up photometry, using the 48" telescope at FLWO, and almost all of them turned out to be stellar systems that mimic planetary transits. We describe our methodology of searching for transits, and give examples of the false positives. _____________________________________________________________________ Pierre Barge (OAMP, France) Dust-gas coupling in protoplanetary disks: back reaction of the particles onto the gas Using a 2D-2phase hyrdodynamical code, developed for the study of protoplanetary disks (Inaba and Barge, A&A 2004), we study a number of situations in which the solid particles of the equatorial layer can drive a significant back reaction of the gas slowing down drift motions. Pierre Barge A new algorithm to detect planetary transits We present a new method for signal denoising and transit detection in stellar photometric light-curves. The plane light-curve can be considered as a 2D image which splits into the upper and the lower part of the plot itself. The resulting images are analysed with an image processing method enabling to develop new algorithm for filtering and detection. These algorithms have been adapted in the case the data issued from the OGLE survey. _____________________________________________________________________ Rory Barnes (U Washington) Packed Planetary Systems I: Evidence Through numerical simulations evidence for the packed nature of planetary systems is presented. Most known systems lie near instability in the sense that slight changes (sometimes less than 10%) in one orbital element can result in an ejection in less than 10^5 orbits. Some systems lie further from instability, but they cannot support an asteroid belt in between the extant planets, let alone an additional planet. The solar system is also shown to be packed. Whether this phenomenon is ubiquitous among planetary systems, or just a function of a small number of observations remains to be seen, but it may provide constraints on planet formation models, and suggest locations to search for additional planets. _____________________________________________________________________ Joseph Barranco (UCSB) Planet Embryos in Vortex Wombs We present the results of high-resolution, three-dimensional (3D) hydrodynamic simulations of the dynamics and formation of coherent, long-lived vortices in stably-stratified protoplanetary disks. Tall, columnar vortices that extend vertically through many scale heights in the disk are unstable to small perturbations; such vortices cannot maintain vertical alignment over more than a couple scale heights and are ripped apart by the Keplerian shear. Short, finite-height vortices that extend only one scale height above and below the midplane are also unstable, but for a different reason: we have isolated an antisymmetric (with respect to the midplane) eigenmode that grows with an $e$-folding time of only a few orbital periods; the nonlinear evolution of this instability leads to the destruction of the vortex. Serendipitously, we observe the formation of 3D vortices that are centered not in the midplane, but at one to three scale heights above and below. Breaking internal gravity waves create vorticity; anticyclonic regions of vorticity roll-up and coalesce into new vortices, whereas cyclonic regions shear into thin azimuthal bands. Unlike the midplane-centered vortices that were placed \textit{ad hoc} in the disk and turned out to be linearly unstable, the off-midplane vortices form naturally out of perturbations in the disk, and are stable and robust for many hundreds of orbits. _____________________________________________________________________ Gibor Basri, Astronomy Dept., Univ. of California, Berkeley Habitable Planets Around Small Stars Most of the stars in the Galaxy have less than half the mass of our Sun. If habitable planets occur around them at a rate which is at all comparable to that for solar-type stars, then low-mass stars are the locus of the "average habitat" for life. This advantage is compounded by their much longer main-sequence lifetimes. NASA's Kepler Mission will conduct the first serious search for terrestrial planets in the habitable zones of solar-type and low-mass stars. The mission is designed to be able to detect "true-Earth analogs", but in fact will conduct a much broader assay of planetary and stellar types. Indeed, the very ubiquity of low-mass stars guarantees that they constitute a major part of the Kepler target list. For Kepler, the faintness of low-mass stars is balanced by the fact that planets in their habitable zones have shorter orbital periods, and the ratio of stellar to planetary area (which determines transit depth) is more favorable (for a given planetary size). M stars have an undeserved reputation as poor places to live near (tidal synchronization and stellar flares being the most cited problems). I argue that neither of these constitutes much of a barrier to habitability. _____________________________________________________________________ A.Bedalov*, R.Neuhaeuser*, E.Guenther** M.Mugrauer* * Astrophysical Institut and University Observatory - Jena, Germany ** Thuringer Landessternwarte Tautenburg, Germany DIRECT IMAGING SEARCH FOR YOUNG MASSIVE PLANETS Everyone would like to see an image of an extrasolar planet. So far, the radial velocity detection method has only detected giant planets indirectly by measuring the wobble of the planet's parent star toward or away from us. Direct imaging of extrasolar planets, then, is highly desirable because one could separate the light from the star and the planet . However, such imaging is difficult. The most important difficulty is the dynamic range of star. Our project is direct imaging detection of sub-stellar companions around young nearby stars, within 150 pc, up to 100 Myrs young. By deep IR imaging with AO (e.g. VLT-NaCo), we can detect brown dwarfs with separations down to 20 AU around the young stars. Direct imaging detection of a massive planet will probably work first around a young stars. _____________________________________________________________________ Chas Beichman, Michelson Science Center Finding Planets: From Spitzer to TPF NASA has made the detection of Earth-like planets around nearby stars a major focus of its space science program.The current program consists of a number of missions, including the Keck Interferometer, Kepler, the Space Interferometric Mission (SIM) and a coronagraphic and interferometric versions of the Terrestrial Planet Finder. I will discuss the overall program with an emphasis on the exciting near term science that will form the scientific context for these missions. Chas Beichman, G. Bryden, K. Stapelfeldt, M. Werner (JPL) G. Rieke, D. Trilling, J. Stansberry (UofA) Disks and Planets: Spitzer Results on Disks and Planets Photometry and spectroscopy with the MIPS and IRS instruments have revealed the presence of disks of material around planet-bearing stars. I will review results obtained to date and discuss the follow-up IRS results of the first disks detected by MIPS. C. Beichman, G. Bryden, K. Stapelfeldt, M. Werner, T. Gautier (JPL) G. Rieke, D. Trilling, J. Stansberry, K. Su, C. Chen, & the MIPS instrument team (UofA) Spectra of debris disks with Spitzer We've used the InfraRed Spectrograph (IRS) on the Spitzer Space Telescope to examine a sample of 45 F5-K5 main-sequence dwarf stars, looking for emission above the stellar photosphere. The three modules used cover each stellar spectra from 8 to 35 um. Observations made during the first six months of Spitzer's mission have been reduced with careful flat-fielding in order to remove residual pixel-to-pixel calibration problems down to <3%. In most cases, the lack of a detected excess rules out the presence of hot (100-1000K) dust at the level of 100-1000 times our zodiacal cloud. Around one star, a nearby K dwarf, we've found prominent dust emission indicative of small, crystalline grains that must be located within 1 AU of the star. We will discuss possible asteroidal or cometary origins for this dust. _____________________________________________________________________ Beth Biller (U Arizona) Simultaneous Differential Extrasolar Planet Imaging (SDI) at the VLT and MMT We discuss data reduction techniques and results from the Simultaneous Differential Imager (SDI) implemented at the VLT (Lenzen et al. 2004) and the MMT. SDI uses a quad filter to take images simultaneously at 3 wavelengths surrounding the 1.62 $\mu$m methane bandhead found in the spectrum of cool brown dwarfs and gas giants. By performing a difference of images in these filters, speckle noise from the primary can be attenuated by a factor of $>$10$^2$. Non-trivial data reduction tools are necessary to pipeline the simultaneous differential imaging. Here we discuss results from a custom algorithm implemented in IDL to perform this reduction. In our commissioning runs at the VLT and MMT, we achieved contrasts up to a factor of 45000 ($\Delta$H=11.7) at a separation of 0.6" from the primary star. With this degree of attenuation, we should be able to image a 2-4 Jupiter mass planet at 5 AU around a 30 Myr star at 10 pc. We believe that our SDI images are the highest contrast astronomical images ever made from ground or space. _____________________________________________________________________ Cullen Blake (Harvard CfA) The PAIRITEL Low-mass Transit Survey Observations of small stellar and sub-stellar objects, such as late M dwarfs and early L dwarfs, have several advantages when searching for extrasolar planets by the transit method. These objects small radii result in large photometric signals, meaning that companions as small as Earth could potentially be detected with current technology. In addition, a companion in a short period orbit, similar to the orbits of the Galilean moons of Jupiter, would result in relatively frequent transits that could be observed at inclination angles up to ted photometric survey of M and L dwarfs using the robotic infrared telescope PAIRITEL located at Mt. Hopkins, Arizona. The photometric precision and stability of the PAIRITEL infrared photometry will be discussed as well prospects for dealing with the intrinsic variability of the M and L dwarfs by making simultaneous observations in the J, H, and K near-infrared bands. _____________________________________________________________________ Laurent Boisnard (Ctr. Nationale d'Etudes Spatiales, France) The COROT mission : search for extrasolar planets by stellar photometry in low earth orbit The COROT space telescope is an experiment of astronomy dedicated to stellar seismology and search for extrasolar planets. The mission is led by CNES in association with French laboratories and with a significant European participation : ESA and several European countries (Austria, Belgium, Germany, Spain) contribute to the payload or to the ground segment. Brazil is about to join the projet for contribution to the ground segment. Based on a PROTEUS low earth orbit recurrent platform, the spacecraft has been in development since October 2000 for a launch by SOYUZ now scheduled in July 2006. After a series of reviews successfully held and recent payload sub-systems deliveries, the instrument is about to be integrated. At this stage of the project, the purpose of our presentation is to give an overview of the experiment and the associated strategy of research, to explain where the critical scientific requirements are for system engineering and to describe some of the cost-effective compromises found for high accuracy photometry in the specific environment of a low earth polar orbit (altitude : 896 km). In a few words, the experiment is designed for photometry in the visible spectrum, with long continuous observing runs (duration of a run : 150 days) and with two scientific channels working simultaneously on adjacent regions of the sky. The focal plane of the wide field camera is split into two CCD detectors for seismology and two for planet search. As far as this second program is concerned, COROT will be able to detect the presence of extrasolar planets when they pass between the satellite and their parent star. By adapting both the integration time and the focus conditions, it is possible to see some luminous flux variations about 500 ppm, compatible with a transit detection on a large variety of stars (magnitude between 12 and 15.5). Moreover, a prism in the beam of the exoplanet channel produces a chromatic dispersion helpful to discriminate planetary transits against star's surface activity. As a result of its photometric accuracy and duty cycle (higher than 90%), COROT will be able to detect large terrestrial planets (twice the Earth radius) on close-in stellar orbits, Neptune and Uranus-like bodies and many hot Jupiters, expanding the statistics on planetary systems. 12000 target stars in a field of view of 4 square degrees will be simultaneously observed. At least five different regions of the sky (at the intersection of the Equatorial plane and the Galactic plane) will be acquired during the whole mission. _____________________________________________________________________ William Borucki and the Kepler Mission Team (NASA Ames Research Center, Moffett Field, CA 94035) Kepler Mission: Determining the Frequency of Terrestrial Planets in the Habitable Zone of Solar-like Stars Kepler is a Discovery-class mission designed to determine the frequency of Earth-size and larger planets in and near the habitable zone (HZ) of spectral type F through M dwarf stars. The instrument consists of a 0.95 m aperture photometer to do high precision photometry of 100,000 solar-like stars to search for patterns of transits. The depth and repetition time of transits provide the size of the planet relative to the star and its orbital period. Multi-band ground-based observation of these stars is currently underway to estimate the stellar parameters and to choose appropriate targets. With these parameters, the true planet radius and orbit scale, hence the relation to the HZ can be determined. These spectra are also used to discover the relationships between the characteristics of planets and the stars they orbit. In particular, the association of planet size and occurrence frequency with stellar mass and metallicity will be investigated. At the end of the four year mission, several hundred terrestrial planets should be discovered with periods between 1 day and 400 days if such planets are common. A null result would imply that terrestrial planets are rare. Based on the results of the current Doppler-velocity discoveries, over a thousand giant planets will also be found. Information on the albedos and densities of those giants showing transits will be obtained. A brief description of merit function that relates the science value to the mission parameters is included. The Mission is now in Phase C/D development and is scheduled for launch in October 2007 into a 372-day heliocentric orbit. ______________________________________________________________________ Geoff Bryden, C. Beichman, K. Stapelfeldt, M. Werner, T. Gautier (JPL) G. Rieke, D. Trilling, J. Stansberry, K. Su, C. Chen, & the MIPS instrument team (UofA) Debris disk frequency from A to M With the MIPS instrument on Spitzer we have surveyed a broad sample of nearby stars for debris disks. Highlights include: 1) a general decline in 24um debris disk frequency around A stars as a function of age, punctuated by large variations in the magnitude of emission at any epoch, 2) a strong trend toward 70um, rather than 24um, excess emission around G stars (i.e. debris analogous to the Kuiper belt, rather than the asteroid belt), and 3) the detection of debris disks around stars known to harbor planets. _____________________________________________________________________ Andrew Collier Cameron, University of St Andrews Christopher Leigh, Liverpool John Moores University Jean-Francois Donati, Observatoire Midi-Pyrenees Prospects for spectroscopic reflected-light searches with CFHT/ESPaDOnS Past attempts to detect starlight from the atmospheres of close-orbiting giant exoplanets have already set deep upper limits on the albedos and radii of the close-orbiting planets of tau Boo, upsilon And and HD 75289. The geometric albedos of tau Boo b and HD 75289b at visual wavelengths have been shown to be substantially less than that of Jupiter. Here we discuss the prospects for pushing these limits even deeper, using the new fibre-fed echelle spectropolarimeter ESPaDOnS, which has been commissioned at CFHT during the last year. We show that ESPaDOnS' combination of high throughput, high PSF stability, image-slicer geometry and full coverage of the optical spectrum are uniquely well-suited to reflected-light searches involving high-precision spectrum subtraction and line-stacking methods. _____________________________________________________________________ Joseph Carson(NASA JPL) An Adaptive Optics Survey for Brown Dwarf Companions to Stellar Systems I describe here procedures and results for the Cornell High-order Adaptive Optics Survey (CHAOS) for brown dwarf companions to stellar systems. This survey consisted of Palomar 200-inch near-infrared coronagraphic observations of 80 stars out to 22 parsecs. The subsequent data analysis revealed that zero systems showed conclusive evidence for a brown dwarf companion. Accompanying Monte Carlo population simulations determined a brown dwarf companion upper limit of 9.7% for the 25-100 AU semi-major axis region. Such a value indicates, at an 89% confidence level, that the "brown dwarf desert" around stellar objects extends further than has been previously reported. _____________________________________________________________________ Eugene Chiang (Berkeley) Planetary Migration and the Role of Resonances I will review how planets migrate in disks composed either of gas or planetesimals. Migration mechanisms will be considered in the context of our observational understanding of disks. Resonant interactions between planets undergoing migration will be described. Trapping of planetesimals into mean-motion resonances will be discussed as a tool to infer the presence of planets and to diagnose planetary migration. _____________________________________________________________________ John E. Chambers, Carnegie Institution of Washington Oligarchic Growth and the Distribution of Mass in the Planetary System Any successful model for the origin of the Solar System should be able to explain the current distribution of matter in the planetary system as a function of distance from the Sun. In particular, one would like to understand why the mass of condensible material in the outer Solar System is much greater than in the inner Solar System, why the most massive planets lie between 5 and 10 AU from the Sun, why most of the mass in the inner Solar System orbits between 0.7 and 1 AU from the Sun, and why Mars is so much smaller than Earth and Venus. To date, it appears that no model has simultaneously explained all of these aspects. The modern characteristics of the Solar System were determined during the last stages of planet formation, but the final configuration was greatly influenced by what went before, especially the ``oligarchic growth'' phase. During this phase, most of the solid mass in the protoplanetary disk remained in small planetesimals, while the largest object in each region grew rapidly. In the inner Solar System, oligarchic growth probably continued until bodies had masses similar to that of Mars. In the outer Solar System, oligarchic growth may have produced bodies large enough to allow rapid accretion of gas, as invoked in the popular ``core-accretion'' model for the formation of the giant planets. Here I will present simulations of oligarchic growth in the protoplanetary nebula using a new technique in which interactions between protoplanets are treated using an N-body integrator, while the effects of a disk of planetesimals are incorporated in a statistical fashion. The effects of different disk surface density profiles will be investigated, together with the role played by the water-ice condensation front or ``ice line''. I will show that most sets of model parameters, including those commonly used in other works, generally do not lead to a final distribution of mass which is similar to the modern planetary system. _____________________________________________________________________ Gail Chauvin (1); Lagrange, A.-M. (2); Dumas, C. (1); Zuckerman, B. (3); Mouillet, D. (2); Song, I. (3); Beuzit, J.-L. (2) and Lowrance, P (4). (1)ESO, Chili (2)LA, France (3)UCLA (4)Spitzer Science Center VLT/NACO Deep Imaging Search for Brown Dwarf and Giant Planet Companions to Young, Nearby Stars In October 2000 we started a deep coronagraphic imaging survey of young, nearby southern associations, using the ADONIS/SHARPII adaptive optics instrument at the ESO/3.6 m telescope and now, since 2002, NACO at the VLT. This study aims at searching for and characterizing substellar companions, i.e brown dwarfs and giant planets, orbiting young stars. The purpose is then to explore fundamental questions regarding the physical, chemical and orbital properties of substellar companions as well as their origins of formation. After briefly describing the sample surveyed including the range of separation and mass explored, we present recent results, including the discovery of a giant planet companion candidate to the young brown dwarf 2M1207. _____________________________________________________________________ James Y-K. Cho and Sara Seager Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, N.W., Washington, D.C. 20015, USA The Effects of Planetary Rotation Rate on Extrasolar Terrestrial Planet Characterization Planets manifest large ranges in physical properties. One extremely important property is the rotation rate, which has a profound influence on the planet s atmospheric circulation and meteorology hence its characterization. Circulation and meteorology directly control the arrangement of clouds, which affect the planet s temperature, albedo, and spectra at the observable surface , be it the cloud top or the land-ocean surface. Current characterization models account neither for the inhomogeneous distribution of clouds nor the complex interplay between planetary properties, large-scale dynamics, and small-scale meteorology. In this work, we investigate the global dynamics and spectra of Earths with varying rotation rates using a multi-dimensional state-of-the-art general circulation model, coupled with a full spectral model. Our calculations show that the Other Earths can exhibit circulation and cloud patterns similar to that of Venus (single broad band) or Jupiter (multiple narrow bands), depending on the rotation rate. While the outgoing long-wave (emitted planetary) radiation flux is correspondingly changed by the new patterns, the disk-averaged spectra are most sensitive to the orientation of the planet in space i.e., whether the planet is viewed equator-on or pole-on. This work represents a first step in a comprehensive exploration of the wide parameter space of physical properties that influence planet characterization. James Y-K. Cho1, Sara Seager1, Sonali S. P. Shukla2, Kristen Menou3, and Bradley M. S. Hansen4 1 Carnegie Institution of Washington, Department of Terrestrial Magnetism, 5241 Broad Branch Road, N.W., Washington, D.C. 20015, USA : 2New York University, Andre and Bella Meyer Hall of Physics 4 Washington Pl., New York, NY 10003, USA 3Department of Astronomy, Columbia University, 550 W. 120th Street, New York, NY 10027, USA 4Division of Astronomy, 8971 Math Sciences, UCLA, Los Angeles, CA 90095, USA AB Atmospheric Circulation of Close-In Extrasolar Giant Planets Under Diabatic Heating A large fraction of the more than 130 extrasolar giant planets currently known has orbits that are very close to their host stars. These close-in planets are likely to be tidally locked and thus continuously heated on the same side. Characterizing the atmospheric circulation and temperature distribution on such planets are key issues for both theory and observation. From transit studies, some physical properties crucial for atmospheric modeling (e.g., radius and mass) have been directly measured for several planets. Past modeling studies have focused on flows driven by simple, ad-hoc models of radiative heating and cooling. In this work, we drive the flow with heating rates derived from a full radiative transfer model. The flow model is a high-resolution equivalentbarotropic model, which is capable of resolving the dynamically critical smallscale eddies and waves as well as reproducing the global zonal jet patterns on all four Solar System giant planets. From our extensive set of simulations, we find that, even if the planets rotate slowly (once per ~100 hours), the effects of rotation cannot be ignored: a strong east-west asymmetry is induced by the rotation on a very short timescale (~several hours), leading to a complex heat distribution at early evolution times. At long times (~10 rotation periods), the flow evolves to a state marked by a broad, well-homogenized equatorial zone and a coherent circumpolar vortex at each pole, as in the recent adiabatic calculations of Cho et al. (2003). The stability of the 2 to 3 zonal jet circulation patterns found in the adiabatic calculation is also a robust feature of the present diabatic calculations. Wave breaking activity in the equatorial zone and propagation across the zone is enhanced by the heating strength. In the near future, some of these findings will be directly tested by observations, such as measurements of day-night temperature difference and temporal variations in the IR flux. _____________________________________________________________________ Mark Clampin and the EPIC Science Team The Extrasolar Planetary Imaging Coronagraph (EPIC) The Extrasolar Planetary Imaging Coronagraph (EPIC) is a Discovery class mission concept recently proposed to NASA. EPIC addresses key science themes in the NASA Origins Roadmap, and the President's Vision for Exploration. The mission is designed to provide the first direct measurements of a broad range of fundamental physical characteristics of giant planets in other solar systems. These characteristics include orbital inclination, mass, brightness, color, the presence (or absence) of CH4 and H2O, and orbital or rotational-driven variability. EPIC utilizes a 1.5 meter telescope, coupled to a Visible Nulling Coronagraph to achieve these science goals. EPIC has been proposed as a Discovery Mission concept. We present an overview of the EPIC mission concept, review its science goals and discuss the technical benefits of the EPIC mission design. Mark Clampin, GSFC David R. Ardila, JHU John E. Krist, JPL David A. Golimowski, JHU Holland C. Ford, JHU Garth D. Illingworth, UCSC/Lick ACS GTO Team Recent results from the ACS Science Team's debris disk program We present recent results from the ACS Science Team's program to image debris disks using the Advanced Camera for Surveys (ACS) coronagraphic imaging mode. ACS features a high resolution camera which optimally samples the telescope's point spread function, with a coronagraphic imaging mode. This capability has been employed to obtain multicolor images of debris disks including HD141569A, AU Microscopii, and the first optical images of a disk around the solar type star HD107146. We discuss the scientific highlights of these observations and discuss the results in the context of our current understanding of the formations of planetary systems. _____________________________________________________________________ William D. Cochran, Michael Endl, Barbara McArthur, and Robert Wittenmyer(U Texas) Planet Discoveries With the Hobby-Eberly Telescope The High Resolution Spectrograph on the Hobby-Eberly Telescope is now routinely producing stellar radial velocities with a precision of 2-3 meters/second. This velocity precision, coupled with queue-mode observing, has allowed us to detect planetary companions to two stars: HD 37605 and rho1 Cancri. The companion to HD 37605 has a minimum mass of 2.84 Jupiter masses. The planet is in a 54.23 day orbit of e = 0.737. The queue-scheduled operation of the Hobby-Eberly Telescope enabled us to discover this relatively short-period planet with a total observation time span of just two orbital periods. The extremely low-mass companion to rho1 Cancri is discussed in detail in the separate presentation at this conference by McArthur et al. We present additional recent results from several HET planet detection surveys which demonstrate the unique capabilities of this facility. These include searches for additional extremely low mass planets, and follow-up high precision radial velocity observations of candidate transiting planet host stars. _____________________________________________________________________ Ben Collins (Caltech) The Formation of Terrestrial Planets and Ice Giants We investigate the growth of proto-planets in a solar system using an N-body scheme optimized for bodies on nearly circular orbits. This routine evolves the orbital elements according to mutual interactions as well as any additional forces. We then add accurate expressions for dynamical friction and planetesimal accretion, and allow the proto-planets to coagulate. We simulate this proto-planetary disk from the last stages of oligarchy into the unstable regime that follows. _____________________________________________________________________ Curtis S. Cooper and Adam P. Showman (U Arizona) Atmospheric dynamics of the transiting exoplanet HD 209458b In this work, we use a primitive equation model adapted from the atmospheric sciences to simulate the dynamics of the atmosphere of HD 209458b within the radiative zone, which extends to ~1 kbar at the object's estimated age of 5.1 Gyr. The simulations employ a scheme for Newtonian cooling to approximate the radiative transfer. In this scheme, the temperature field is relaxed to the temperature profile in radiative equilibrium. We present simulations demonstrating the flow geometry for a range of assumptions about the radiative equilibrium temperature profile. Our simulations show---in general agreement with the predictions of Showman \& Guillot (2002)---fast equatorial jets of $\rm \sim$5 $\rm km s^{-1}$ at altitude (10-1000 mb), which approach or exceed the speed of sound in the fluid. At these low pressures, the hottest regions of the atmosphere are blown downwind from the substellar point where the planet receives the highest irradiation. Deeper down ($\rm >$10 bars), wind velocities decrease and the equatorial jet gives way to a weak meridional flow and relatively uniform temperature profile. The simulations show a 400 K day-night temperature difference at 1 bar, with the peak in temperature at about 100 degrees longitude downstream from the substellar point. This temperature difference leads to a phase difference of over a day between the time of the optical transit and the time of peak infrared emission from the planet, which is in principle measurable with sufficiently sensitive instruments. We diagnose the energy and angular momentum budgets of the planet and test the hypothesis that the object's evolution has been affected by the dissipation of atmospheric kinetic energy into the deep interior. We note, however, that the integration times of our simulations are relatively short compared to the radiative relaxation timescale at high pressures, so that the total kinetic energy of the atmosphere once it reaches steady-state will be significantly larger than our simulations predict. This research is supported by NSF grant AST-0206269, NASA Ames Research Center Cooperative Agreement (NCC 2-5518), and NASA GSRP NGT5-50462. _____________________________________________________________________ Justin Crepp (U Florida) Laboratory Testing of High-order Image Masks for TPF-C We have built and tested the first 8th-order and 12th-order binary notch filter image masks. These masks combine a suite of advantages for high-contrast imaging and demonstrate key technologies for the Terrestrial Planet Finder Coronagraph (TPF-C). In particular, they substantially relax telescope pointing requirements and are less sensitive to low-order optical aberrations compared to 4th-order masks. We report results of their performance with monochromatic and broadband light in the Space Astronomy Instrumentation Lab (SAIL) - TPF testbed, at the University of Florida. _____________________________________________________________________ W.C. Danchi(1), R. Barry (1), J. Rajagopal(2), R.J. Allen(2), D.J. Benford(1), D. Deming(1), D.Y. Gezari(1), M. Kuchner(3), D.T. Leisawitz(1), R. Linfield(4), J.D. Monnier(6), L.G. Mundy(7), C. Noecker(4), L.J. Richardson(1), S. Seager(8), W.A. Traub(3), D. Wallace(1) (1) NASA Goddard Space Flight Center (2) Space Telescope Science Institute (3) Harvard-Smithsonian Center for Astrophysics (4) Ball Aerospace (5) California Institute of Technology (6) University of Michigan (7) University of Maryland (8) Carnegie Institution of Washington The Fourier-Kelvin Stellar Interferometer (FKSI): A progress report The Fourier-Kelvin Stellar Interferometer (FKSI) is a mission concept for an imaging and nulling interferometer for the near-infrared to mid-infrared spectral region (3-8 microns). FKSI is conceived as a scientific and technological pathfinder to TPF/DARWIN as well as SPIRIT, SPECS, and SAFIR. It will also be a high angular resolution system complementary to JWST. The scientific emphasis of the mission is on the evolution of protostellar systems, from just after the collapse of the precursor molecular cloud core, through the formation of the disk surrounding the protostar, the formation of planets in the disk, and eventual dispersal of the disk material. FKSI will also search for brown dwarfs and Jupiter mass and smaller planets, and could also play a very powerful role in the investigation of the structure of active galactic nuclei and extra-galactic star formation. We report additional studies of the imaging capabilties of the FKSI with various configurations of two to five telescopes, studies of the capabilities of FKSI assuming an increase in long wavelength response to 10 or 12 microns (depending on availability of detectors), and preliminary results from our nulling testbed. _____________________________________________________________________ John Debes (Penn State) Searching for Planets Around White Dwarfs White dwarfs, the stellar remnants of stars between 1-8 M$_\odot$, represent a unique population to look for extrasolar planetary companions. They are orders of magnitude fainter than their progenitors and any putative companions have adiabatically expanded their orbits, becoming easier to separate from the glare of their host white dwarf. We present the latest results from a high contrast imaging campaign of nearby white dwarfs that uses the NICMOS coronagraph on the Hubble Space Telescope, PUEO/KIR on the Canada France Hawaii Telescope, and Altair/NIRI on the Gemini North Telescope. We discuss several candidate companions as well as avenues for future work. _____________________________________________________________________ Drake Deming (1), Timothy M. Brown (2), David Charbonneau (3), Joseph Harrington (4), and Jeremy Richardson (1) (1)NASA GSFC (2)High Altitude Observatory/National Center for Atmospheric Research, Boulder (3)Harvard CfA (4)Cornell A New Search for Carbon Monoxide Absorption in the Transmission Spectrum of the Extrasolar Planet HD 209458b We have revisited the search for carbon monoxide absorption features in transmission during the transit of the extrasolar planet HD 209458b. In August-September 2002 we acquired a total of 1077 high resolution spectra (resolving power 25,000) in the K-band (2 micron) wavelength region using NIRSPEC on the Keck~II telescope during three transits. These data are more numerous and of better quality than the data analyzed in an initial search by Brown et al. Our analysis achieves a sensitivity sufficient to test the degree of CO absorption in the first overtone bands during transit, based on plausible models of the planetary atmosphere. We analyze our observations by comparison to theoretical tangent geometry absorption spectra, computed by adding height-invariant ad hoc temperature pertubations to the model atmosphere of Sudarsky et al., and by treating cloud height as an adjustable parameter. We do not detect CO absorption. The strong 2-0 R-branch lines between 4320 and 4330 wavenumbers have depths during transit less than 1.6 parts in 10,000 in units of the stellar continuum (3 sigma limit), at a spectral resolving power of 25,000. Our analysis indicates a weakening similar to the case of sodium, suggesting that a general masking mechanism is at work in the planetary atmosphere. Under the interpretation that this masking is provided by high clouds, our analysis defines the maximum cloud top pressure (i.e., minimum height) as a function of the model atmospheric temperature. For the relatively hot model used by Charbonneau et al. to interpret their sodium detection, our CO limit requires cloud tops at or above 3.3 mbar, and these clouds must be opaque at a wavelength of 2 microns. High clouds comprised of submicron-sized particles are already present in some models, but may not provide sufficient opacity to account for our CO result. Cooler model atmospheres, having smaller atmospheric scale heights and lower CO mixing ratios, may alleviate this problem to some extent. However, even models 500K cooler that the Sudarsky et al. model require clouds above the 100 mbar level to be consistent with our observations. Our null result therefore requires that clouds exist at an observable level in the atmosphere of HD 209458b, unless this planet is dramatically colder than current belief. _____________________________________________________________________ Ian Dobbs-Dixon, UC Santa Cruz, 813.459.2774 Spin-Orbit Evolution of Short-Period Planets The negligible eccentricity of all extrasolar planets with periods less than 6 days can be accounted for by dissipation of tidal disturbances within their envelopes that are induced by their host stars. In the period range of 7-21 days, planets with circular orbits coexist with planets with eccentric orbits. These are referred to as the borderline planets. We propose that this discrepancy can be attributed to the variation in spin-down rates of young stars. In particular, prior to spin-down, dissipation of a planet's tidal disturbance within the envelope of a sufficiently rapidly spinning star can excite eccentricity growth and, for a more slowly spinning star, at least reduce the eccentricity-damping rate. In contrast, tidal dissipation within the envelope of a slowly spinning low-mass mature star can enhance the eccentricity-damping process. On the basis of these results, we suggest that short-period planets around relatively young stars may have a much larger dispersion in eccentricity than those around mature stars. We also suggest that because the rate of angular momentum loss from G and K dwarfs via stellar winds is much faster than the tidal transfer of angular momentum between themselves and their very short (3-4 days) period planets, they cannot establish a dynamical configuration in which the stellar and planetary spins are approximately parallel and synchronous with the orbital frequency. In principle, however, such configurations may be established for planets (around G and K dwarfs) with orbital periods of up to several weeks. In contrast to G and K dwarfs, the angular momentum loss due to stellar winds is much weaker in F dwarfs. It is therefore possible for synchronized short-period planets to exist around such stars. The planet around Tau Boo is one such example. _____________________________________________________________________ U. Dyudina (1), P.Sackett(2), D. Bayliss(2), L Dones(3), H. Throop(3), C. Porco(4), S. Seager(5) (1)Caltech (2)Australian National University, Canberra, Australia (3)SWRI,Boulder (4)CICLOPS/Space Science Institute,Boulder (5)DTM,CIW, Washington Phase Light Curves for Extrasolar Jupiters and Saturns We predict how a remote observer would see the brightness variations of giant planets similar to those in our Solar System as they orbit their central stars. We model the geometry of Jupiter, Saturn and Saturn's rings for varying orbital and viewing parameters. Scattering properties for the planets and rings at wavelenghts 0.6-0.7 microns are assumed to follow these observed by Pioneer and Voyager spacecraft, namely, planets are forward scattering and rings are backward scattering. Images of the planet with or without rings are simulated and used to calculate the disk-averaged luminosity varying along the orbit, that is, a light curve is generated. We find that the different scattering properties of Jupiter and Saturn (without rings) make a substantial difference in the shape of their light curves. Saturn-size rings increase the apparent luminosity of the planet by a factor of 2-3 for a wide range of geometries, an effect that could be confused with a larger planet size. Rings produce asymmetric light curves that are distinct from the light curve of the planet without rings, which could resolve this confusion. If radial velocity data are available for the planet, the effect of the ring on the light curve can be distinguished from effects due to orbital eccentricity. Non-ringed planets on eccentric orbits produce light curves with maxima shifted relative to the position of the maximum planet's phase. Given radial velocity data, the amount of the shift restricts the planet's unknown orbital inclination and therefore its mass. Combination of radial velocity data and a light curve for a non-ringed planet on an eccentric orbit can also be used to constrain the surface scattering properties of the planet and thus describe the clouds covering the planet. To summarize our results for the detectability of exoplanets in reflected light, we present a chart of light curve amplitudes of non-ringed planets for different eccentricities, inclinations, and the viewing azimuthal angles of the observer. _____________________________________________________________________ A. Eggenberger (1), G. Chauvin (2), S. Udry (1), J.-L. Beuzit (3), A.-M. Lagrange (3), (1)Obs. Geneve, Switzerland (2)ESO (3)LAG, France WHAT DO OBSERVATIONS TELL US? We have undertaken a systematic adaptive optics search for (faint) close stellar companions to nearby dwarf stars, some of them known to harbour a planet, the others thought to be single, for comparison. This survey aims at investigating several fundamental, yet open questions regarding the occurrence of planets in binary and multiple star systems: what is the global effect of stellar duplicity on planet formation and subsequent evolution? Are the properties of planets found in binaries different from the ones of planets orbiting single stars? Are there many giant planets in "close" binaries? In this contribution we will present the current results of our survey, which is nearing completion. We will also discuss how stellar duplicity can be used to test planet formation models and possibly discriminate between them. _____________________________________________________________________ Josh Eisner (Caltech) Probing Sub-AU Radii of Young Circumstellar Disks The structure of young circumstellar disks, and in particular of the regions within 1 AU of the central star, has important implications for disk accretion and planet formation. We have observed a sample of T Tauri and Herbig Ae/Be stars with the Keck and Palomar Testbed Interferometers, supplemented by echelle spectroscopy and optical through near-IR photometry. With these data, we constrain the geometries and temperatures of inner circumstellar dust disks, and compare our measurements with the predictions of physical disk models. Analyzing our measured inner disk properties with those expected for magnetospheric accretion models, we find evidence that gaseous disk material extends further in toward the star than dust. We compute the expected orbits for migrating giant planets halted in 2:1 resonances with the inner disk, and compare these with the observed semi-major axis distribution of extra-solar planets. Finally, we discuss implications for terrestrial planet formation. _____________________________________________________________________ Michael Endl(1), William D. Cochran(1), Diane B. Paulson(2), Phillip J. MacQueen(3), Robert G. Tull(1) (1)U Texas (2)NASA GSFC (3)High Altitude Observatory, National Center for Atmospheric Research, Boulder "A Low Frequency Of Close-In Giant Planets Around M Dwarfs" We present high precision radial velocity data for a sample of 81 M dwarf obtained with the Hobby-Eberly Telescope and the Harlan J. Smith 2.7 m Telescope at McDonald Observatory, as well as the Keck I Telescope on Mauna Kea to search for giant planetary companions. None of the stars show variability indicative of a giant planet in a short period orbit. The M dwarfs included in our survey have thus a frequency of close-in giant planets of < 1.2%. So far, GJ 876 remains the only unambiguous case of an M dwarf orbited by Jupiter-class planetary companions. This might indicate an overall low incidence of giant planets in the low mass part of the HR-diagram. _____________________________________________________________________ Eric B. Ford (UC Berkeley) Increasing the Sensitivity of Planet Searches with Dynamic Scheduling High-precision radial velocity planet searches have surveyed $\sim\!2000$ nearby stars and detected $\sim\!130$ planets. While these same stars likely harbor many additional planets, they will become increasingly challenging to detect, as they tend to have relatively small masses and/or relatively long orbital periods. Therefore, observers are increasing the precision of their observations, continuing to monitor stars over decade timescales, and also preparing to survey thousands more stars. Given the considerable amounts of telescope time required for such observing programs, it is important use the available resources as efficiently as possible. Previous studies have found that a wide range of predetermined scheduling algorithms result in planet searches with similar sensitivities. We have developed adaptive scheduling algorithms which have a solid basis in Bayesian inference and information theory and also are computationally feasible for modern planet searches. We have performed Monte Carlo simulations of plausible planet searches to test the power of adaptive scheduling algorithms. Our simulations demonstrate that planet searches performed with adaptive scheduling algorithms can simultaneously detect more planets, detect less massive planets, and measure orbital parameters significantly more accurately than comparable surveys using a non-adaptive scheduling algorithm. We expect that these techniques will be particularly valuable for the N2K radial velocity planet search for short-period planets, as well as future astrometric planet searches with the Space Interferometry Mission which aim to detect terrestrial mass planets. _____________________________________________________________________ H. Ford (JHU), W. Sparks (STScI), and R. White (STScI) An ACS Coronagraphic Search for Planets Around Alpha Cen A & B ACS High Resolution Camera coronagraphic images of Alpha Cen A and B were taken with a sequence of intermediate band filters at two different epochs. The filter bandpasses and wavelengths were chosen such that the observations could be analyzed with spectral deconvolution. We present the results from two independent approaches to analyzing the observations and dealing with the presence of the second star (B or A) that is in the field of view. We compare our detection limits as this stage in the data analysis to the magnitudes expected for gas giants that are within the zones of stable orbits around A and B. _____________________________________________________________________ J.J. Fortney & M.S. Marley (NASA Ames Research Center) Reflection Spectra of Extrasolar Giant Planets: New Models and Optimized Filter Calculations Using a model atmosphere code that has been applied extensively to planets and brown dwarfs, we compute pressure-temperature profiles and reflection spectra of extrasolar giant planets (EGPs) at a variety of orbital distances and gravities. With an eye towards optical coronagraphic imaging, we compute the locations and widths of medium- and wide-band filters that will allow for first-order characterization of EGP atmospheres with a minimum of integration time. We compute magnitudes and colors for these models in a variety of filters and compare the model-derived values to those of our solar system's giant planets. For instance, we find that that the spectral signature of water clouds, which form below Teff ~ 300 K, leads to a significant change in spectral slope that is easily detectable with only two wide-band filters. We also discuss how photochemically-derived hazes, which are found in the stratospheres of all the solar system's giant planets, may complicate efforts to characterize EGP atmospheric properties. _____________________________________________________________________ Ovidiu Furdui and Rainer Spurzem Astronomisches Rechen-Institut, Heidelberg, Germany Dynamical Evolution of Planets with Belt Interaction The orbital evolution and stability of planetary systems with interaction from the belts is studied using the standard phase-plane analysis. The belt is assumed to have power-law density prowhich corresponds to the Keplerian orbit, there are other edges of the belt. The existence of these orbital circularization due to frictional force from the belt. It is interesting that we found a limit cycle of semi-attracter. Our results show that for the planets, the probability to move stably around the inner edge is larger than the one to move around the outer edge. It is also interesting that there is a limit cycle of semi-attractor for a particular case. Applying our results to the Solar System, we a natural mechanism to do the orbit rearrangement for the larger Kuiper Belt Objects and thus successfully explain the absence of these objects beyond 50 AU. _____________________________________________________________________ Jian Ge, Department of Astronomy, The University of Florida All Sky Extrasolar Planet Survey with Sloan Telescope A decade-long, all-sky, extrasolar planet survey at the Sloan 2.5 meter wide field telescope is being planned for monitoring 1,000,000 stars with V = 8-13 in the solar neighborhood with a goal to detect 100,000 extrasolar planets between 2008-2020. This survey is enabled by a new generation multiple object Doppler radial velocity instrument based on a dispersed fixed-delay interferometer called Exoplanet Tracker (ET). The instrument capable of simultaneously observing hundreds of stars increases the planet survey speed by more than two orders of magnitude over current single object echelle instruments. One channel of the instrument is designed for monitoring F, G, K type stars in the visible, the other channel is designed for monitoring M type stars in the near infrared aiming at detection of habitable planets. Following the commissioning of the first multiple object instrument at Sloan in March and April 2005, a pilot program will be carried out to monitor 20,000 stars with V = 8 -11 in 2005-2008. Currently a trial survey with a single object ET is being conducted with the KPNO 0.9 meter Coude telescope. Initial survey results will be reported. ______________________________________________________________________ Andrea Ghez (UCLA) TBD ______________________________________________________________________ Brett Gladman and Collin Chan University of British Columbia A rogue planet scenario for the creation of the Extended Scattered Disk. The extended scattered disk (trans-neptunian objects with large semimajor axes and eccentricities but perihelia above about 40 AU) seems to require a cosmogonic explanation becuase scattering off the current giant planets cannot produce these objects in sufficient numbers. Stellar encounter scenarios appear feasible, although they require the correct encounter timing, distance, and angle to produce the observations. We present results of numerical simulations which show that scenarios in which there were additional `rogue planets' in the outer Solar system (with masses of order 10 percent of Uranus) which efficiently raise perihelia of scattered disk objects during the first 100-200 Myr of the Solar System's history before being eliminated from the System. _____________________________________________________________________ C.A. Grady, the STIS GTO, HST GO 9136 Team, and the HST GO 10177 Team High Contrast Imaging of Protoplanetary Disks: The STIS and NICMOS Perspective We present the results of high contrast coroaagraphic imaging surveys of protoplanetary disks including both classical T Tauri stars and Herbig Ae stars with HST STIS and, an on-going survey with NICMOS. The white-light STIS coronagraph covered 0.2-1.0 microns and was sensitive to remnant envelopes, bipolar jets and chains of HH knots, as well as reflection nebulosity from the disks. The observed disk surface brightness spans at least 2 orders of magnitude at 2 arcsec from the star. The optical surface brightness of the large disks correlates with the strength of the mid-IR PAH features, as seen by ISO, for the Herbig Ae stars. Some of the classical T Tauri stars have both coronagraphic imagery and FUV long-slit spectra. The optical surface brightness of the nebulosity around these stars appears to correlate with the strength of the spatially extended fluorescent molecular hydrogen emission. This trend may also be present among the Herbig Ae stars, albeit for an extremely small sample. While the NICMOS survey is still underway, the stars which have been observed to date suggest that a similar trend is present in the near-IR. Both the PAH emission and the molecular hydrogen fluorescence require direct illumination of the emitting material by a FUV light source. For comparatively isolated PMS stars, such as have been imaged with HST, such a source is the PMS star itself. The optically bright disks are those, therefore, with flared disk surfaces, while the dark disks in the sample are consistent with disks with constant opening angle or those which are geometrically flatter. Two disks in the sample have inner zones which are dark, and outer, brighter rings, suggesting that the dark zones are a byproduct of grain settling and subsequent dissoiation or removal of macromolecules and molecular gas. _____________________________________________________________________ J H Hough(1) , P W Lucas (1), J A Bailey (2), E Hirst (3) (1)Centre for Astrophysics Research, University of Hertfordshire, Hatfield AL10 9AB, England (2) Anglo-Australian Observatory, Epping Laboratory, PO Box 296, Epping NSW 2121, Australia (3) Particle Instruments Group, Science & Technology Research Institute, University of Hertfordshire, Hatfield AL10 9AB, England PLANETPOL: A new polarimeter for the direct detection & characterization of scattered light from extra-solar planets The advantages of using polarimetry to make direct detections of the light from extra-solar planets are discussed. The performance of a polarimeter with sufficient sensitivity to make such direct detections is presented together with some preliminary data from observations of stars with known extrasolar planets. _____________________________________________________________________ Nader Haghighipour (University of Hawaii) Formation of habitable planets in binary star systems. Current models of planet formation, explain how planets are formed around single stars. However, binary stars are the most common outcome of the star formation process. There is also considerable evidence for protoplanetary disks in young multiple star systems. Observations show that initial conditions for planet formation exist in binary star systems, as well. A survey of all currently known extrasolar planets indicates that close to 25% of their hosting stars are members of binary systems. Almost all of these binaries are wide with separations ranging from 250 to 1000 AU. At these separations the effect of the binary companion on the formation of planets around the other star is negligible. However, in close binary systems, the gravitational perturbation of the companion can have considerable effects on the structure of the circumstellar disk, formation of planetesimals and protoplanets, and ultimately on the formation of habitable planets, and water-delivery mechanisms. In this paper, I will present results of simulations of the dynamical evolution of planetesimals around one of the stars of a binary, and discuss the effects of the companion on the formation of Earth-like planets in the habitable zone of such a star. The implication of type II runaway growth of such simulations is that terrestrial planet embryos, and thus habitable planets, can form in protoplanetary disks in the presence of a massive binary companion. Within the context of habitability, I will present the results of a large survey of the parameter space of binary-planetary systems in search of regions where habitable planets can have long-term stable orbits, and will also discuss the effect of the companion on mechanisms of delivery of water to such planets. _____________________________________________________________________ Lynne Hillenbrand (Caltech) TBD _____________________________________________________________________ Matthew J. Holman (1), Norman W. Murray (2) 1: Harvard-Smithsonian Center for Astrophysics 2: Canadian Institute for Theoretical Astrophysics, University of Toronto The Use of Transit Timing to Detect Extrasolar Planets Future surveys for transiting extrasolar planets, including the space-based mission Kepler (Borucki et al 2003), are expected to detect hundreds of Jovian mass planets and tens of terrestrial mass planets. For many of these newly discovered planets, the intervals between successive transits will be measured with an accuracy of 0.1--100 minutes. We show that these timing measurements will allow for the detection of additional planets in the system (not necessarily transiting), via their gravitational interaction with the transiting planet. The transit time variations depend on the mass of the additional planet, and in some cases Earth-mass planets will produce a measurable effect. In some cases, when two or more planets transit the same star, the densities of the planets can be estimated. _____________________________________________________________________ Keith Horne, St.Andrews University Colin Snodgrass, Queens' University Belfast An Optimal Strategy for the RoboNet-1 Microlens Planet Survey Intensive monitoring of the lightcurves of Galactic Bulge microlens events is probably the fastest way to discover `cool planets' in 1-10 AU orbits around late-type stars with sensitivity to small planets approaching the mass of the Earth. In 2004 over 600 such events were identified by the OGLE-III and MOA experiments, and the lightcurves of several dozen of these were followed up using 1-m class telescopes coordinated by the PLANET, microFUN and MOA teams. In 2005, the UK RoboNet-1 experiment will augment PLANET's microlens follow-up network by linking three 2m robotic telescopes: the Liverpool Telescope in La Palma, Canary Islands and the two Faulkes Telescopes in Maui, Hawaii and Siding Springs, Australia. With limited observing time and so many events underway, observers face a non-trivial dilemma in deciding which events to observe and for how long on each night. RoboNet's robotic telescopes require fully automatic algorithms. I describe a metric and optimisation scheme for allocating observing time among ongoing events, designed to maximise the probability of detecting new planets. Cool planet detection capabilities of telescopes employing this strategy are investigated using Monte-Carlo simulations. _____________________________________________________________________ Hannah Jang-Condell (Carnegie) How Shadowing and Illumination in Disks Affects Planet Formation Radiative transfer is an important process in protoplanetary disks. Stellar illumination, in particular, is primarily responsible for setting the temperature and density structure of passively accreting protoplanetary disks. Perturbations in the structure of a disk such as clumping, gap-opening, and dust-settling can create shadows and bright spots which in turn further perturb the disk's structure. Density and temperature variations resulting from the dynamical interactions between a planet and a disk can be further enhanced by these cooling and heating effects, leading to alterations in planetary migration rates, planetary growth, and other important planet formation processes. I present radiative transfer calculations on a three-dimensional disk perturbation induced by a protoplanet. These temperature perturbations can affect ice formation vis-a-vis the "snow line" which in turn affects the accumulation of water onto a planet embryo as well as the growth rate of protoplanets. The change in the local pressure gradient caused by these temperature perturbations also changes the migration rate of the planet. I will also address some possible observational signatures of the presence of planets in disks. Small planets which are insufficiently massive to open a full annular gap in the disk are likely to be out of the range of observability, but gaps with large extent may be detectable in images and SEDs. _____________________________________________________________________ Ray Jayawardhana (University of Toronto) Disks Around Young Brown Dwarfs and Potential for Planet Formation I will review recent findings by our group and others on the frequency and characteristics of disks around young very low mass stars and brown dwarfs, covering the entire mass range from just above the hydrogen burning limit all the way to primary masses approaching the planetary domain. I will also present some new results on accretion, jets, disk masses and disk lifetimes, and discuss the potential for planet formation around sub-stellar objects. _____________________________________________________________________ John A. Johnson UC Berkeley Geoff Marcy UC Berkeley Debra Fischer San Francisco State Universtity Searching For Planets Orbiting Subgiants The vast majority of planet-bearing stars have masses less than 1.3 solar, due to the target selection criteria in Doppler searches. Main sequence stars more massive than 1.3 solar masses tend to be fast rotators, have fewer spectral lines and display a large amount of atmospheric ``jitter.'' One method to circumvent these difficulties is to observe stars after they evolve off of the main sequence. These subgiant stars are ideal planet search targets because they are cooler and rotate slower than their main-sequence, F- and A-type progenitors. We present a Doppler survey of a sample of 200 subgiants in order to determine whether or not stars with masses between 1.3 and 2.5 solar harbor planets, and whether the occurrence rate of planets is dependent upon the mass of the host star. _____________________________________________________________________ Hugh Jones (University of Hertfordshire NOT Liverpool John Moores University as originally registered) The Anglo-Australian Planet Search The Anglo-Australian Planet Search is a long-term programme being carried out on the Anglo-Australian Telescope to search for giant planets aroun nearby Solar type stars. We began observing in January 1998 observing 200 target stars over 20 nights per year, and have very recently grown to more than 60 nights per year targetting an expanded sample. Twenty planet candidates with M sin i values ranging from 0.2 to 10 Mjup have been found from the programme, four planet candidates have been confirmed using our data and several found by other programmes disputed. Our precision Doppler velocity measurements are made with the an echelle spectrograph with an iodine absorption cell. The iodine cell enables us to achieve measured long-term velocity stability of 2 m/s (for suitably stable stars) down to our survey magnitude limit. This stability will be discussed in the context of our latest results and our announcement of the HD70642 system (the best 'Solar System' analog yet found). _____________________________________________________________________ Paul Kalas (UCB), James Graham (UCB), and Mark Clampin (NASA GSFC) New HST images of dust belts around nearby main sequence stars. We present new HST optical data that resolve debris disks around nearby A - K stars with ages betwen 0.2 and 1 Gyr. In all cases, structure is belt-like, with evidence of azimuthal and radial asymmetry that can be linked to planetary perturbations. The large radii of the inner edges - two to three times that of our Kuiper Belt - flag systems where dynamical scattering or migration may have increased the semi-major axes of extrasolar Neptunes. In the best resolved example, the sharpness of the inner and outer belt boundary can be measured and related to theoretical calculations of disk-planet dynamical interactions. _____________________________________________________________________ Stephen Kane (St Andrews, UK) Hunting for Extra-Solar Planets in the Draco Field with the WASP Prototype The Wide Angle Search for Planets prototype (WASP0) is a wide-field instrument used to search for extra-solar planets via the transit method. Here we present the results of a monitoring program which targeted field stars in Draco. This programme involved the monitoring of around 35000 field stars for a period of two consecutive months. We describe the transit detection algorithm used to extract transit candidates from the thousands of lightcurves that have been produced. Analysis of the lightcurves resulted in the detection of 11 multi-transit candidates and 3 single-transit candidates, two of which we recommend for further follow-up. Monte-Carlo simulations which match the observing parameters have been performed to estimate the expected number of transit candidates from this survey. A comparison of the expected number with the number of candidates detected is used to discuss limits on planetary companions to field stars. _____________________________________________________________________ L.D. Keller(1), G.C. Sloan(2), K.I. Uchida(2), E. Leibensperger(1), W.J. Forrest(3), J. Najita(4), C. H. Chen(5), J. D. Green(3), F. Kemper(6), D. M. Watson(3), L. Hartmann(7), T. L. Herter(2), N. Calvet(7), P. D'Alessio(8), E. Furlan(2), B. Sargent(3), P. Morris(5), D. J. Barry(2), P. Hall(2), B. R. Brandl(9), P. C. Meyers(7), and J. R. Houck(2) (1)Ithaca College (2)Cornell University (3)University of Rochester (4)National Optical Astronomy Observatory, Tucson (5)California Institute of Technology (6)UCLA (7)CfA, Harvard (8)UNAM, Mexico (9)Sterrewacht Leiden, Netherlands Mid-infrared spectroscopy of emission from polycyclic aromatic hydrocarbons around Herbig AeBe stars We present Spitzer Infrared Spectrograph observations of 4 Herbig AeBe stars including HD 141569. All of the sources exhibit strong emission from polycyclic aromatic hydrocarbons (PAH) in the 5-20 micron range; in some of the spectra PAHs dominate the emission. A detailed examination reveals variations in the relative contributions of the skeletal PAH modes (6-8 microns), the C-H bending modes (8-13 microns). The variations in strengths between skeletal and C-H bending modes suggests variations in ionization ratios of the PAHs in our sample. Since AeBe stars are commonly characterized by strong crystalline silicate emission in this spectral region, we also examine the relative contributions (and possible confusion) of silicate and PAH features in the spectra of our sample of stars. _____________________________________________________________________ Stephan Kellner (Max-Planck-Institut for Astronomy, Heidelberg) Spectral Differential Imaging - How close are we imaging an extra solar planet? Speckle Noise is one of the most limiting factors in order to detect companions close (< 1") to a young star by the means of Adaptive Optics systems. We present here a method to reduce speckle noise by using differential imaging techniques of simultaneously obtained frames around the methane absorption band at 1.62 microns. We give a brief overview about the technical aspects, introduce furthermore a particularly for this application developed data reduction pipeline. Moreover we show very promising results obtained by oberserving several nearby young stars. We discuss both the enormous potential of Spectral Differential Imaging and also its limitations in terms of detection limits. _____________________________________________________________________ Hubert Klahr and Anders Johansen Max-Planck-Institute for Astronomy, Heidelberg Dust Diffusion, Transport and Concentration in 3D MHD Simulations of Protoplanetary Accretion Disks It is of great importance to understand the transport and mixing properties of turbulence in protoplanetary accretion disks. First, diffusion directly influences the chemical evolution in the disk and has an impact on the growth of dust particles to planetesimals. As a result the transport of dust grains and molecules determines the observational features of the disk. As a first order approach one usually assumes the diffusion parameter to be exactly equal to the turbulent viscosity. We demonstrate in how far this assumption is justified. Therefore, we study the transport of small grains in a direct numerical simulation of turbulence in a protoplanetary accretion disk driven by the magneto rotational instability. We adopt the Pencil code in a shearing sheet approximation to measure the diffusion properties of the disk turbulence in relation to the measured Reynolds and Maxwell stresses. We find the diffusion to be anisotropic and show how it relates to the measured stresses. We also study the transient concentration of solids in the turbulent flow pattern and the implications on the formation of planetesimals. _____________________________________________________________________ David Koch, William Borucki, J. Lissauer, David Mayer, Janice Voss, NASA Ames Research Center, Moffett Field, CA, Gibor Basri, Alan Gould, Univ. California-Berkeley, Berkeley, CA, Timothy Brown, High Altitude Observatory, Boulder, CO, Douglas Caldwell, Edna DeVore, Jeff Garside, Jon Jenkins, SETI Institute, Mountain View, CA, William Cochran, Univ. Texas-Austin, Austin, TX Edward Dunham, Lowell Observatory, Flagstaff, AZ, Nick Gautier, Jet Propulsion Laboratory, Pasadena, CA, John Geary, David Latham, Smithsonian Astrophysical Observatory, Cambridge, MA, Yoji Kondo, Goddard Space Flight Center, Greenbelt, MD, David Monet, US Naval Observatory, Flagstaff, AZ, Eric Bachtell, Jeff Baltrush, William Deininger, Adam Harvey, Lorna Hess-Frey, Dan Peters, Mike Weiss, Ball Aerospace and Technologies Corp., Boulder, CO, Riley Duren, Jet Propulsion Laboratory, Pasadena, CA, Rick Thompson, Orbital Sciences Corp., Mountain View, CA, Kepler Mission Design The Kepler Mission is in the development phase with launch planned for 2007. The primary mission goal is to reliably detect a significant number of Earth-size planets in the habitable zone of solar-like stars. (See W. Borucki, this conference.) The mission design allows for exploring the diversity of planetary sizes, orbital periods, stellar spectral types, etc. (also see papers by D. Latham and G. Basri, this conference) In this paper we describe the technical approach taken for the mission design; describing the flight and ground system, the detection methodology, the photometer design and capabilities, and the way the data are taken and processed. Finally the detection capability in terms of planet size and orbit are presented as a function of mission duration and stellar type. _____________________________________________________________________ Eiichiro Kokubo (National Astronomical Observatory of Japan) Protoplanets to Terrestrial Planets We investigate the formation process of terrestrial planets from protoplanets by using N-body simulations. As the initial conditions we adopt the oligarchic growth model of protoplanets. We derive the statistical properties of the resultant terrestrial planets from the results of about 100 runs. We show the dependence of the mass and orbital properties of the terrestrial planets on the mass and distribution of the initial protoplanets. The formation probability of habitable planets is also discussed. _____________________________________________________________________ Maciej Konacki, Caltech Precision radial velocities of double-lined spectroscopic binaries and the search for extrasolar planets in binary stellar systems A spectroscopic technique employing an iodine absorption cell (I_2) to superimpose a reference spectrum onto a stellar spectrum is currently the most widely adopted approach to obtain precision radial velocities (RVs) of solar-type stars. It has been used to detect ~80 extrasolar planets out of ~130 know. Yet in its original version, it only allows us to measure precise radial velocities of single stars. I will present a novel method employing an I_2 absorption cell that enables us to accurately determine radial velocities of both components of double-lined binaries. Initial results based on the data from the Keck~I telescope and HIRES spectrograph demonstrate that 20-30 m/s radial velocity precision can be routinely obtained for "early" type binaries (F3-F8). For later type binaries, the precision reaches ~10 m/s. I will discuss my ongoing search for extrasolar planets in binary stellar systems and the application of the new technique to stellar astronomy. In particular, such RVs when combined with the interferometric data collected with the Palomar Testbed Interferometer can routinely produce masses of the binary components accurate at the level of 0.1 to 1.0 % and challenge modern models of stellar structure and evolution. ____________________________________________________________________ Marc Kuchner (Princeton University) and Sara Seager (Carnegie DTM) Extrasolar Carbon Planets We suggest that extrasolar planets $\sim$1--60~$M_{\bigoplus}$ may commonly form substantially from carbon and silicon carbide like carbonaceous chondrites. This planet-formation pathway requires only a factor of two local enhancement of the protoplanetary disk's C/O ratio above solar, a condition that the evaporation of interstellar organics may create interior to where the temperature reaches 350~K in some protoplanetary disks. These planets may be distinguished by hydrocarbon-rich spectra and tar-covered surfaces. Diamond shells can protect these planets from carbon depletion at high temperatures and high fluxes of ionizing radiation. The planets around pulsar PSR 1257+12 or the newly discovered close-in Neptune-mass planets may represent this new class of carbon planets. Marc Kuchner and Andrew Youdin (Princeton University) Matthew Bate (University of Exeter) Delivery of Water to the Terrestrial Planets Via Ice Grains Following a Shifting Snow Line Protoplanetary disks evolve through a stage when viscous heating flags yet dust opacity still shields the midplane from direct sunlight. During this cold phase late in the evolution of the solar nebula, water likely condensed from the nebula and fell onto Earth, Venus and Mars as millimeter-sized ice grains. We investigated the flow of grains through the nebula onto protoplanets and planetesimals using analytic and numerical models and calculate grain capture probabilities as a function of protoplanet mass and orbital eccentricity. Our models support water-rich beginnings for Mars and Venus, and they predict a systematic, rather than stocastic, distribution of water-rich extrasolar planets. In this distribution, $\sim 1 M_{\bigoplus}$ planets have a larger mass fraction of water than larger or smaller bodies and planets on more eccentric orbits receive more water. Besides delivering the Earth's water, this mechanism can also supply the nitrogen in the Earth's atmosphere and the noble gasses in Jupiter's envelope, though some low-temperature condensates found in the inner solar system may still require comets or asteroids to supply them. _____________________________________________________________________ David W. Latham (CfA), Timothy M. Brown (HAO), Mark E. Everett (PSI), and David G. Monet (USNOFS) Target Selection for the Kepler Mission Kepler will stare at more than 100,000 solar-type stars continuously for four years to look for transits by earth-sized planets. Because of limited access to the Deep Space Network for data transmission, only the CCD pixels that include selected targets will be returned to Earth for analysis. Magnitude-limited samples are dominated by hot stars and giants that are too large to allow the detection of earth-sized transits. Therefore the Kepler team has undertaken a photometric and spectroscopic survey of the Kepler target region, more than 150 square degrees in Cygnus and Lyra, to provide the information needed for the selection of optimum targets. The multi-band CCD photometry is being carried out with the 48-inch telescope at the Whipple Observatory on Mount Hopkins, Arizona, using SDSS filters supplemented by a Mg b filter. Spectroscopy of candidate targets identified by the photometry will be carried out with the Hectochelle multi-fiber spectrograph on the MMT. The goal is to provide effective temperatures, metallicities, reddening, extinction, and surface gravities so that stellar radii can be estimated. Radial and rotational velocities will be reported for those stars that are observed spectroscopically. The resulting Kepler Input Catalog containing on the order of 10 million stars is scheduled for delivery in December 2006. _____________________________________________________________________ Gregory Laughlin(1), Peter Bodenheimer(1), Fred Adams(2) (1)University of California (2)University of Michigan The Core Accretion Model Predicts few Jovian-Mass Planets will be found Orbiting M-Dwarfs The favored theoretical explanation for giant planet formation -- in both our solar system and others -- is the core accretion model (although it still has some serious difficulties). In this scenario, planetesimals accumulate to build up planetary cores, which then accrete nebular gas. With current opacity estimates for protoplanetary envelopes, this model predicts the formation of Jupiter-mass planets in 2--3 Myr at 5 AU around solar-mass stars, provided that the surface density of solids is enhanced over that of the minimum-mass solar nebula (by a factor of a few). Working within the core-accretion paradigm, we present theoretical calculations which show that the formation of Jupiter-mass planets orbiting M dwarf stars is seriously inhibited at all radial locations (in sharp contrast to solar-type stars). Planet detection programs sensitive to companions of M dwarfs will test this prediction in the near future. _____________________________________________________________________ T. Joseph W. Lazio (Naval Research Laboratory), Jill C. Tarter (SETI Institute), D. J. Wilner (Center for Astrophysics) The Square Kilometer Array and The Cradle of Life The Square Kilometer Array (SKA) is a unique radio telescope being designed by an international consortium with the aim of surpassing the capabilities of the current generation of radio telescopes by at least an order of magnitude. By virtue of its sheer sensitivity (10^6 m^2 collecting area), high frequency coverage (at least to 25 GHz), and long baselines (~ 3000 km), the SKA will play a pivotal role in astrobiological studies. With its frequency coverage, the SKA will be sensitive to emission from dust grains with sizes of order 1 cm, thereby probing a crucial stage in the assembly of planets. With its sensitivity and long baselines, the SKA will be able to *image* proto-planetary disks in nearby star-forming regions and even monitor the evolution of structures within those disks (``movies of planetary formation''). Finally, it will also be able to assess the extent to which interstellar molecules are incorporated into proto-planetary disks. Basic research in radio astronomy at the NRL is supported by the Office of Naval Research. T. Joseph W. Lazio, Naval Research Laboratory William M. Farrell, NASA/GSFC Planetary Magnetospheres, Planetary Habitability, and Direct Detection of Extrasolar Planets By virtue of their planetary-scale magnetic fields, the Earth and all of the gas giants in our solar system possess solar-wind deformed magnetospheres. The magnetic polar regions of these ``magnetic planets'' produce intense, aurora-related radio emission from solar-wind powered electron currents. In the case of the Earth, its magnetic field also shields its atmosphere and surface from cosmic rays, potentially playing a key role in making its surface habitable. We describe a combined theoretical and observational program designed to test the extent to which auroral radio emission from the known extrasolar planets may be detectable over interstellar distances. Various forms of a radiometric Bode's Law have been developed to describe the dependence of auroral radio emission upon a planet's distance from the Sun and its magnetic moment. We have applied a typical form for the radiometric Bode's Law to the current census of extrasolar planets. We predict that the auroral radio emission of the known extrasolar planets may be within reach of current radio telescopes, under favorable circumstances, and should definitely be detectable with future instruments. We are also conducting a systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array. The current limits set by the VLA images are approaching, but do not yet provide strong constraints on, the predictions of the model. Basic research in radio astronomy at the NRL is supported by the Office of Naval Research. _____________________________________________________________________ Man Hoi Lee (UCSB) On the 2:1 Orbital Resonance in the HD 82943 Planetary System We present an analysis of the HD 82943 planetary system based on a radial velocity data set that combines new measurements obtained with the Keck telescope and the published CORALIE measurements.We examine simultaneously the goodness of fit and the dynamical properties of the best-fit double-Keplerian model as a function of the poorly constrained eccentricity and argument of periastron of the outer planet's orbit. There are two local minima of comparable $\chi_\nu^2$, but they are both dynamically unstable if the orbits are assumed to be coplanar. However, the minima are relatively shallow, and there is a wide range of fits outside the minima with reasonable $\chi_\nu^2$. For an assumed coplanar inclination $i = 30^\circ$ ($\sin i = 0.5$), only the good fits with both of the lowest order, eccentricity-type mean-motion resonance variables at the 2:1 commensurability, $\theta_1$ and $\theta_2$, librating about $0^\circ$ are stable. For $\sin i = 1$, there are also some good fits with only $\theta_1$ librating that are stable for at least $10^4$ years. The libration amplitudes are about $10^\circ$ (or less if $\sin i < 1$) for the stable good fit with the smallest libration amplitudes of both $\theta_1$ and $\theta_2$. Thus the two planets in the HD 82943 system are almost certainly in 2:1 orbital resonance, with at least $\theta_1$ librating, and may even be consistent with small-amplitude librations of both $\theta_1$ and $\theta_2$. _____________________________________________________________________ Zoe Leinhardt (University of Maryland) Out of the rubble: The growth of protoplanets We present results from a dozen direct N-body simulations of terrestrial planet formation with various initial conditions. In order to increase the realism of our simulations and investigate the effect of fragmentation on protoplanetary growth, we have developed a self-consistent planetesimal collision model that includes fragmentation and accretion of debris. In our model we treat all planetesimals as gravitational aggregates so that gravity is the dominant mechanism determining the collision outcome. We compare our results to those of Kokubo and Ida (2002) in which no fragmentation is allowed---perfect merging is the only collision outcome. After 500,000 yr of integration our results are virtually indistinguishable from those of Kokubo and Ida (2002). We find that the number and masses of protoplanets, and time required to grow a protoplanet, depends strongly on the initial conditions of the disk and is consistent with oligarchic theory. We have determined that the elastistity of the collisions, which is controlled by the normal component of the coefficient of restitution, does not significantly affect planetesimal growth over a long timescale. Particles below our resolution limit (debris) are treated semi-analytically, and we find that planetesimals accrete debris faster than they are ground down. As a result, at the end of oligarchic growth the debris component it negligible and does not affect the dynamics of the protoplanets. _____________________________________________________________________ Doug Lin (UCSC) The Mass-Period Relation of Extra Solar Giant Planets. Based on the convensional sequential accretion scenario, we consider the growth of planetesimals to cores and protoplanetary embryos in a gaseous medium. In disks with similar mass distribution as the minimum mass nebula, cores may attain sufficiently large masses to induce the onset of efficient gas accretion beyond he snow line. But, in more massive disks, gas giants may form in broad regions including locations interior to the snow line. Gas accretion is terminated by the local clearing through gap formation and global depletion due to photo evaporation. Based on the observed distribution of disk mass and disk migration models, we determine a mass-period distribution for systems with single gas giant planets. We show the dependence of this distribution for a range of stellar metallicity and masses. We predict the existence of a desert of planets with modest masses and intermediate periods. We also show that abundance of currently observable gas giants rapidly increases with stellar metallicity and masses, which is consistent with the observational results. _____________________________________________________________________ Charles H. Lineweaver(1) and Daniel Grether(2) (1)Planetary Science Institute, Australian National University, Canberra, ACT, Australia (2)Department of Astrophysics, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia How Dry is the Brown Dwarf Desert?: Quantifying the Relative Number of Planets, Brown Dwarfs and Stellar Companions around Nearby Sun-like Stars The formation of a binary star via molecular cloud collapse and fragmentation, and the formation of a massive planet around a host star via protoplanetary disk accretion, both involve the production of a binary system, but are recognized as distinct processes. The formation of companion brown dwarfs with masses in between the stellar and planetary mass ranges may have elements of both, or some more distinct mechanism. To constrain and differentiate models of the formation of these companions, we analyse the close companions ($P < 5$ years) of nearby Sun-like stars ($d < 25$ pc & $d < 50$ pc). By using the same sample to extract the relative numbers of stellar, brown dwarf and planetary companions, we are able to verify the existence of the brown dwarf desert and decribe it quantitatively. The mass function drops by more than an order of magnitude from $1.0 M_{\odot}$ stars to the brown dwarf mass range and rises by approximately half an order of magnitude as we move from brown dwarfs to Jupiter mass objects. The companion mass function in the brown dwarf and stellar mass range, has a different shape than the mass function of single stars and free-floating brown dwarfs. We discuss the possible origins of this difference in terms of formation mechanisms or post-formation migratory processes. _____________________________________________________________________ Michael C. Liu (U Hawaii) Debris Disks around M Dwarfs The vast majority of stars are the low-mass M dwarfs, but these objects have been relatively neglected in studies of disk and planet formation. At very young ages, low mass stars commonly have primordial disks; however, little is known about their subsequent evolution. We discuss the observed paucity of debris disks around low mass objects in the solar neighborhood compared to disks around higher mass stars. We then highlight the one well-studied M dwarf debris disk around the young star AU Mic. By virtue of the star's proximity (10 pc) and youth (12 Myr), multi-wavelength infrared and sub-millimeter observations achieve excellent sensitivity of the dust content and detailed morphology. We compare the AU Mic disk to other known young debris disk systems, and consider its properties in the context of current models of planet formation. Characterization of the AU Mic disk provides new insight into the physical nature of the long-studied archetype beta Pictoris. These two systems likely represent a key phase in disk evolution, between the primordial disks around pre-main sequence stars and the very tenuous debris disks around old stars. _____________________________________________________________________ James Lloyd (Cornell University), Mark Swain (Laboratoire d'Astrophysique Observatoire de Grenoble) Vincent Coude du Foresto (LESIA/Observatoire de Paris-Meudon) Wesley Traub, (Harvard-Smithsonian Center for Astrophysics) Christopher Walker, (University of Arizona) John Storey (University of New South Wales) The Antarctic Plateau Interferometer The Antarctic Plateau Interferometer (API) is an instrument concept capable of extensive unique discovery space science in a variety of areas including exoplanets, accretion, YSO's, and AGNs. To study exoplanets in the habitable zone, API would use three 2 meter class telescopes, high-dynamic range spectroscopy, and differential closure phase to achieve 1:1e5 contrast ratio measurements. API would achieve this performance using proven technology at the best accessible site on Earth for infrared interferometry. At Dome C Antarctica, the combination of low levels of atmospheric turbulence (resulting in the best seeing ever measured) and low thermal background enable an interferometer with 2 m class telescopes to exceed substantially the performance of existing instruments. API will be packaged in shipping containers so that the instrument can be demonstrated on the sky in the northern hemisphere and then shipped, with a minimum of disassemble, to Dome C. The combination of using existing interferometer technology (adapted to the Antarctic environment) and containerized packaging makes it possible to begin operation at Dome C in 5 years. In addition to delivering a high-impact science program, API could test instrument technology for space interferometry missions such as Darwin and TPFI. _____________________________________________________________________ Christophe Lovis, Michel Mayor, Stephane Udry (Obs. Geneve, Switzerland) Searching for extrasolar planets around red giants in intermediate-age open clusters We present preliminary results from our radial-velocity survey of ~50 red giants in the clump of 8 open clusters in the southern sky. The data have been obtained with the CORALIE spectrograph at La Silla and extend over more than one year. Cluster membership allows precise knowledge of red giant masses, which are very uncertain for field red giants. The age of the clusters (200 Myr to 4 Gyr) involves red giant masses between 3.7 and 1.3 M_Sun, allowing us to explore a new primary mass domain in the search for extrasolar planets. Interestingly, the radius reached by these giant stars at the RGB tip is not a strong limitation to the existence of short-period planets. Low-mass companions should be able to survive around 2 M_Sun giants for periods as short as ~40 days. The main limitation to this research will be the stellar RV jitter, which is poorly understood for giant stars. Our first results show that two thirds of the stars have a radial-velocity dispersion below 50 m/s, with a peak at about 25 m/s. We discuss the dependence of the RV dispersion on the position in the H-R diagram. We also present a few promising candidates, among which a possible 2 M_Jup planet around a 2.4 M_Sun star. _____________________________________________________________________ Phil Lucas, University of Hertfordshire and P F Roche, U Oxford A Gemini survey of the bottom of the IMF in the Trapezium Cluster We present the results of a deep imaging survey of the Trapezium Cluster with Gemini South/Flamingos. The survey is sensitive to objects with masses as low as 2 to 4 Jupiter masses, this limit being subject to significant theoretical uncertainties in the mass-luminosity relation. The mass function for luminosity selected brown dwarf candidates is found to decline into the planetary mass regime, though the slope of the decline depends on the presently unknown degree of contamination by background stars among the faintest sources. The incidence of wide binaries is found to be lower in brown dwarfs than in stars with a modest statistical significance. Some probable wide star+brown dwarf binaries are detected at separations too small for a chance association. However these pairs exist in apparent small-N groups which may be dynamically unstable, so the results do not necessarily conflict with the ejected stellar embryo hypothesis of Reipurth & Clarke. _____________________________________________________________________ Kevin Luhman (Harvard CfA) Spitzer Observations of Brown Dwarf Disks Through the GTO programs of the Spitzer IRAC, MIPS, and IRS instrument teams, we are obtaining extremely sensitive mid-infrared photometry and spectroscopy of circumstellar disks around a large sample of young low-mass stars and brown dwarfs in nearby star-forming regions. By combining these data with the predictions of models of circumstellar disks, we constrain various properties of these disks, such as their geometries (flat or flared?), inner radii, dust compositions, and lifetimes. With these results, we address the fundamental issue of how circumstellar disks -- and hence the initial conditions of planet formation -- change from stars to brown dwarfs. _____________________________________________________________________ Bruce Macintosh (LLNL)and James Graham (U California/Berkeley and U California/Santa Cruz) Direct Detection of Extrasolar Planets with Adaptive Optics on 8-30m telescopes Current radial-velocity searches for extrasolar planets, though powerful, are fundamentally constrained in the range of orbits they can access by the need for a near-complete orbital period: the largest detectable semi-major axis only grows with time to the 2/3 power. In the next several decades, indirect detection will barely reach planets with orbits comparable to Saturn. However, planets in our solar system exist at wider separations (such as Neptune, with an orbital period of 164 years). Resolves extrasolar dust disks frequently exceed 100 AU, some with evidence for perturbing planets in wide orbits. To probe the 5-100 AU range different techniques are needed. Direct detection of photons emitted by extrasolar planets is one such technique, but requires contrast levels of 10^7 (for warm self-luminous planets) to 10^9 for mature Jupiter analogs. Adaptive optics technology has matured to the point where it is now possible to design systems that can achieve contrast >10^7 on 8-10m telescopes. I will review the key issues in designing such a system, and present Monte Carlo simulations that show their likely science reach. Studies of the planet population in this region will shed considerable light on the mechanisms of planet formation and migration. In the next decade, even larger telescopes such as the Thirty Meter Telescope (TMT) will be operational. Such telescopes can achieve even higher contrasts, but will be operating in competition with space-based planet imaging missions such as TPF-C. To justify a planet-detection AO system for TMT we must identify a compelling scientific role that exploits the advantages of extremely large filled-aperture telescopes. I will present a comparative analysis of TPF and TMT for Jovian planet detection. One mission for which TMT could excel is imaging of the planet formation process - exploiting the high angular resolution and small inner working distance of a 30-m telescope to probe ~5 AU scales in nearby star forming regions. _____________________________________________________________________ Jean-Luc Margot (Cornell University) HST observations of binary Kuiper Belt Objects (KBOs) Our Hubble Space Telescope (HST) program is designed to characterize the orbital and physical properties of six confirmed KBO binaries [Margot et al., 2003]. Our primary goals are to measure the masses/densities of KBOs, to identify the binary formation mechanism, and to place constraints on the primordial Kuiper belt. The densities of large Kuiper belt objects provide estimates of the ice/rock fraction which depends on the amount of Oxygen sequestered in CO in the early solar nebula. The range of densities admissible by the new Oxygen abundances of Asplund et al. differs considerably from previous estimates. Most KBOs in our sample must have high albedos, otherwise their densities would be implausibly low. For unit density, we find that KBOs in our sample have albedos in the range 8-40%, much higher than indicated by the long-held assumption that KBOs have comet-like albedos of ~4%. This implies that the total mass in the Kuiper belt may have been over-estimated by an order of magnitude. The size distribution of KBOs must similarly be revised to account for the smaller, brighter objects. The high albedos presumably require a continuous collisional resurfacing in the Kuiper Belt. The binary formation mechanisms proposed to date make important predictions for the characteristics of the binaries and the environment at the time of formation. The distributions of semi-major axes, eccentricities, and inclinations of the binary pairs available to date do not appear to support the binary formation of model of Funato et al. nor that of Goldreich et al. References Asplund et al., A&A 417, 2004. Funato et al., Nature 427, 2004. Goldreich, Lithwick, Sari, Nature 420, 2002. Margot, Brown, Trujillo, Sari, HST General Observer Prgm 9746, 2003. _____________________________________________________________________ Barbara McArthur et al. McArthur, Barbara E.(1); Endl, Michael(1); Cochran, William D.(1); Benedict, G. Fritz(1); Fischer, Debra A.(2); Marcy, Geoffrey W.(2); Butler, R. Paul(3); Naef, Dominique(4); Mayor, Michel(5); Queloz, Diedre(5); Udry, Stephane(5); Harrison, Thomas E.(6) (1)U Texas (2)Berkeley (3)Carnegie Institution of Washington (4)San Francisco State University (5)Obs. Geneve, Switzerland (6)New Mexico State University Detection of a Neptune-Mass Planet in the ?1 Cancri System Using the Hobby-Eberly Telescope We report the detection of the lowest mass extrasolar planet yet found around a Sun-like star-a planet with an Msini of only 14.21+/-2.91 M? in an extremely short period orbit (P=2.808 days) around ?1 Cancri, a planetary system that already has three known planets. Velocities taken from late 2003-2004 at McDonald Observatory with the Hobby-Eberly Telescope revealed this inner planet at 0.04 AU. We estimate an inclination of the outer planet ?1 Cancri d, based on Hubble Space Telescope Fine Guidance Sensor measurements that suggest an inner planet of only 17.7+/-5.57 M?, if coplanarity is assumed for the system. _____________________________________________________________________ Renu Malhotra (Arizona) TBD _____________________________________________________________________ Geoff Marcy (Berkeley) TBD _____________________________________________________________________ Mark Marley, Jonathan Fortney, Olenka Hubickyj, Jack Lissauer (NASA Ames Research Center), Peter Bodenheimer (UC Santa Cruz) Young Jupiters are Faint The early evolution of young extrasolar giant planets is of considerable interest. EGPs are brightest and most easily detectable when they are young. However traditional planet evolution models, which progress from arbitrarily hot and extended initial states, are unreliable at young ages. Despite modelers? impassioned caveats, the lack of alternatives has led various tabulations of model luminosities for young planets to be routinely used to plan observations and estimate detectability of these objects at ages of less than twenty or so million years. This model shortcoming led our group to produce the first self-consistent evolutionary calculation for a one Jupiter-mass planet including all stages of formation, accumulation, and subsequent cooling. Our calculations include the accretion of an approximately ten Earth mass core followed by the subsequent rate-limited flow of nebular gas onto that core. After the total planet mass reaches 1 MJ accretion is terminated and the planet begins to cool adiabatically, as in standard cooling sequences. Since the evolutionary calculation begins with a planet that has been self-consistently brought to its initial state, we believe the behavior at young ages is more reliable than previous computations. We find that while our total luminosity agrees well with other models at ages in excess of about 30 million years, at younger times our predicted luminosity is substantially?by up to a factor of two or more?lower. This result implies that extrasolar giant planets around very young stars may be substantially more difficult to detect than expected. We will present our evolution calculation as well as model spectra and photometry of young EGPs. _____________________________________________________________________ Eduardo Martin (UCF) Title: Detection of planets around ultracool dwarfs: present and future Abstract: We will report on ongoing observational efforts to detect planets around ultracool dwarfs using radial velocity and imaging techniques. Results on ultracool dwarf binaries will be shown, including dynamical mass measurements and binary frequencies. We will also discuss the status of planet candidates. We will present the NAHUAL project, which is a high-resolution near-infrared echelle spectrograph for the 10.4-meter telescope in La Palma (GTC). We estimate that this instrument will reach the required sensitivity to detect planets down to a few earth masses in the habitable region around ultracool dwarfs. _____________________________________________________________________ Francisco Javier Martin-Torres (NASA LRC) Is the OH a key-species to look for in our search for life in other planets? Meinel[1] first identified the bright airglow in the night sky as produced by the emission from the rotational-vibrational bands of hydroxyl (OH). The emission from these bands has been subsequently observed in oxygen-supported flames and stellar atmospheres[2], interstellar medium[3], comets[4,5] and other astronomical objects[6,7]. In the Earth's atmosphere the two most important sources of OH are the reactions of hydrogen (H) and ozone (O3) and the photolysis of water vapour (H2O)[8]. Both are exothermic reactions and the rotational and vibrational levels of OH formed and responsible of the visible and infrared emissions, have excitation temperatures that differ from the local kinetic temperature. This implies that the assumption that they emit according to the Planck function at the local kinetic temperature is no longer valid and non- Local Thermodynamic Equilibrium (non-LTE) models must be used to simulate and analyze them[9]. In the near future new optical and infrared spectral separation techniques will help us to analyze spectra from exoplanetary atmospheres. The detection of OH in a planetary atmosphere using those spectra would be an indirect evidence of the presence of ozone and water vapour (and, perhaps, life). Nevertheless OH is not a key-species the current proposed missions to search and characterize exoplanets as the Terrestrial Planet Finder[10]. Here, based on the analysis of the measurements of the OH emissions in the atmosphere of the Earth taken by space-borne instruments is evaluated the potential non-LTE OH emissions in the visible and infrared. This is an important issue to deal with in order to perform an appropriate design of future missions. REFERENCES: [1] Meinel, I.A. B., OH Emission Bands in the Spectrum of the Night Sky, Astrophysical Journal, vol. 111, p.555-568, (1950) [2] Grevesse, N, Sauval, A. J. and van Dishoeck, E. F., An analysis of vibration-rotation lines of OH in the solar infrared spectrum, Astronomy and Astrophysics (ISSN 0004-6361), vol. 141, no. 1, Dec. 1984, p. 10-16 (1984) [3] Robinson, B. J. and McGee, R. X., OH Molecules in the Interstellar Medium, Annual Review of Astronomy and Astrophysics, vol. 5, p.183-197 (1967). [4] Meisel, D. D. and Berg, R.A., High resolution spectrophotometry of selected features in the 1.1 micron spectrum of Comet Kohoutek-1973f, Icarus, vol. 23, Nov. 1974, p. 454-458 (1974). [5] Tozzi, G. P., Feldman, P. D., and Weaver, H. A., Observations of the OH Meinel system in comet P/Swift-Tuttle, Astron. Astrophys. 285L, L9-L12 (1994) [6] Lewis, B. M., David, P., Le Squeren, A. M., Mainline OH detection rates from blue circumstellar shells, Astronomy and Astrophysics Supplement, v.111, p.237 (1995) [7] Sylvester et al., Detection by ISO of the far-infrared OH maser pumping lines in IRC+10420, Royal Astronomical Society, Monthly Notices, vol. 291, p. L42-L46 (1997) [8] Brasseur, G. and Solomon, S. Aeronomy of the Middle Atmosphere, 2nd ed., D. Reidel Publishing Co., Norwell, Mass. (1986) [9] Mlynczak, M. G.and Solomon, S., Middle atmosphere heating by exothermic chemical reactions involving odd-hydrogen species, Geophysical Research Letters (ISSN 0094-8276), vol. 18, p. 37-40 (1991) [10] NASA's Terrestrial Planet Finder mission: the search for habitable planets, Proceedings of the Conference on Towards Other Earths: DARWIN/TPF and the Search for Extrasolar Terrestrial Planets, 22-25 April 2003, Heidelberg, Germany. Edited by M. Fridlund, T. Henning, compiled by H. Lacoste. ESA SP-539, Noordwijk, Netherlands: ESA Publications Division, ISBN 92-9 ns Division, ISBN 92-9 _____________________________________________________________________ Michel Mayor et al.(Obs. Geneve, Switzerland) SEARCHING FOR VERY LOW MASS PLANETS The one meter/second precision for the radial velocity measurements currently achieved with the HARPS spectrograph is well adapted to explore the exoplanet mass domain below the mass of Saturn. Several exoplanets have already been detected with masses as small as Neptune's mass. These detections could add constraints on the formation of exoplanets by comparison with statistical predictions recently proposed by several teams. _____________________________________________________________________ Tsevi Mazeh(1), Omer Tamuz(1), Shay Zucker(2) & Andrzej Udalski(3) (1)Tel-Aviv, Israel (2)Obs. Geneve, Switzerland (3)European Southern Observatory, Germany Sys-Rem - A new Algorithm to Remove Systematic Effects in Large Photometric Datasets: Application to OGLE Carina Lightcurves with New Transit Candidates We constructed a new algorithm, Sys-Rem, to remove systematic effects in a large set of lightcurves obtained by a photometric survey. The algorithm can remove any systematic effects, like the ones associated with atmospheric extinction, detector efficiency, or PSF changes over the detector. Sys-Rem works without any prior knowledge of the effect, as long as it linearly appears in many stars of the sample. The algorithm, which was originally developed to remove atmospheric extinction effects, is based on a lower rank approximation of matrices. It is specially useful in cases where the uncertainties of the measurements are unequal. For equal uncertainties Sys-Rem reduces to the Principal Components Analysis (PCA) algorithm. Application of Sys-Rem to the OGLE Carina dataset revealed new significant transit candidates. _____________________________________________________________________ Stanimir Metchev and Lynne Hillenbrand (Caltech) Low-Mass Companions to Young Solar Analogs We present preliminary results from a coronagraphic survey of young nearby Sun-like stars using the Palomar and Keck adaptive optics systems. We have targeted 251 solar analogs (F5-K5) at 20-160 pc from the Sun, spanning the 3-3000 Myr age range. The youngest (<500 Myr) of these have been imaged with deeper exposures to search for sub-stellar companions. The deep survey of 100 stars is sensitive to brown-dwarf companions at separations >0.5" from their host stars, with sensitivity extending to planetary-mass (5-15 Jupiter masses) objects at wider (>3") separations. Based on the discovery of a number of new low-mass (<0.2 solar masses) stellar companions, we infer that their frequency at >20~AU separations may be greater (12%) than that found from radial velocity surveys probing <4 AU separations (6%; Mazeh et al. 2003). In addition to revealing the multiplicity of Sun-like stars at wide separations and low binary mass ratios, this survey may also help guide future radial velocity studies of the planetary frequency around binary stars, that can then be compared with the emerging results on single stars. Finally, we report the astrometric confirmation of the first sub-stellar companion from the survey - an L4 brown dwarf at a projected distance of 44 AU from the 500 Myr-old star HD 49197. Based on this detection, we estimate that the frequency of sub-stellar companions to solar-type stars is at least 1%, and possibly of order a few per cent. _____________________________________________________________________ C. McCarthy, D. Fischer (San Francisco State Univ.), G. Marcy (U.C. Berkeley) Search for Terrestrial Planets with the Space Interferometry Mission The Space Interferometry Mission will return unprecedented astrometric precision of 1 microarcsecond, enabling the detection of planets with masses few times the mass of the Earth around the nearest stars. With launch in 2010, SIM will discover and provide dynamical masses for the planets observed by Terrestrial Planet Finder. To achieve 1 microarcsecond precision in narrow angle mode, SIM requires an exquisitely stable reference frame established by distant background stars, all within 1 degree of each target star to be searched for planets. We present the current status of SIM's search for extrasolar terrestrial planets. _____________________________________________________________________ Caer-Eve McCabe(1), A.M. Ghez(1), L. Prato(1) & G. Duchene(2) (1)UCLA (2)Grenoble Observatory T Tauri Disk Evolution A high spatial resolution, 10-20 micron, survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis has been carried out at the Keck telescope. Combined with resolved near-infrared photometry and spectroscopic accretion diagnostics, the survey probes the inner ~AU region of the circumstellar disks around these young stars and finds that ten percent of stars with a mid-infrared excess do not appear to be accreting. In contrast to an actively accreting disk system, these 'passive disks' have significantly lower K-L colors that are, in most cases, consistent with photospheric emission, suggesting the presence of an inner disk hole. In addition, there appears to be a significant mass dependence associated with the presence of a passive disk, with all passive disks having spectral types later than M2.5. The presence of a companion does not appear to be related to the presence of an inner disk hole; the passive disks sample the entire range of binary separations present in the sample and a similar fraction of passive disks is observed in a sample of single stars. The mass dependence makes the possibility that the passive disks are caused by the presence of a nearby, as yet unresolved, companion unlikely, and suggests that these passive disks represent a subset of T Tauri stars that are in the process of losing their disk material, with the disk evolving in an inside-out manner. In this framework, the timescale of disk evolution appears to be dependent on the mass of the central star, with disks around low mass stars taking longer to clear out the inner disk region. Caer-Eve McCabe, Gaspard Duchene, Andrea Ghez, Francois Menard, Christophe Pinte, Karl Stapelfeldt (UCLA-JPL-Grenoble team) Resolving the structure and grain size distribution of T Tauri disks through multi-wavelength Monte Carlo simulations of scattered light images. Resolved scattered light images of T Tauri circumstellar disks, in combination with dust thermal emission maps in the millimeter regime, provide a powerful tool that can be used to probe the grain sizes in these young, presumably protoplanetary, systems. By obtaining spatially resolved scattered light observations over as wide a wavelength range as possible on systems where the disk structure and mass is well constrained, we can investigate the wavelength dependence of the dust scattering properties and, in the case of disks which are close to edge-on, the vertical disk structure. Using the Keck II Adaptive Optics system with NIRC2, the facility near-infrared camera, we have spatially resolved the GG Tau, HK Tau and HV Tau circumstellar disks in scattered light in the 3-5 micron wavelength range. The angular dependence of scattered light at these wavelengths does not behave as expected from standard ISM dust models, with the disks consistently showing evidence for more forward throwing dust at longer wavelengths. Multi-wavelength Monte Carlo modeling of these systems finds evidence for larger than ISM grain sizes and, in at least two of these cases, evidence for dust settling. _____________________________________________________________________ Stanimir Metchev (Caltech), Joshua Eisner (Caltech), Lynne Hillenbrand (Caltech), Sebastian Wolf (MPI) Structure and Dynamical Evolution in the AU Mic Disk We present adaptive optics observations of the near-IR scattered light from the inner 17-60 AU of the AU Mic disk. We find evidence for clumpy disk sub-structure, confirming previous observations, suggestive of the existence of embedded planets. However, no >1 Jupiter-mass planets are detected at >20 AU separations from the star. We also observe a reddening trend in the color of the scattered light with decreasing disk radius, indicating the presence of larger grains at smaller orbital separations. Using a radiative transfer code to simultaneously model the optical to near-IR scattered light surface brightness profile and the optical to sub-mm spectral energy distribution, we constrain the disk mass, minimum and maximum grain sizes, and the inner radius of the disk. We then compare the equally-young AU Mic and beta Pic systems and observe similar radial structure in the two debris disks: both exhibit chages in the power-law of their scattered light profiles over a discrete range of disk radii. From a scaling anlysis of the physical parameters of the two systems, we conclude that the observed homology is the signature of either grain growth or Poynting-Robertson drag in circumstellar disks undergoing a transition between a primordial and a debris state. These processes self-consistently explain the observed radial dependence of the grain size in the AU Mic disk. Thus, the comparative study of the co-eval and homologous AU Mic and beta Pic debris disks provides more accurate empirical constraints on the relevant dynamical time-scales in circumstellar disks than previously possible from analyses of individual systems. _____________________________________________________________________ Amaya Moro-Martin (U Arizona) Signatures of planets in debris disks Main sequence stars are commonly surrounded by debris disks, composed of cold far-IR emitting dust presumably generated by a reservoir of undetected dust-producing planetesimals. In debris disks harboring massive planets, the trapping of dust in gravitational resonances with the planet creates a density enhancement in a ring-like structure outside the orbit of the planet, while gravitational scattering with the planet creates a clearing of dust inside the planet's orbit. Massive planets, therefore, can create structure in the dust disk, and the study of this structure can help us survey a range of planetary parameters that are not detected by other methods. The Spitzer infrared space telescope will obtain spatially unresolved spectrophotometric observations of many potentially diverse debris disk systems with embedded planets. We discuss how the structure carved by massive planets affects the shape of a debris disk's spectral energy distribution (SED), and consequently how the SED may be used to infer the presence and properties of planets. We show that the SED modeling presents some degeneracies that can only be broken if spatially resolved images of the dust disks are obtained. _____________________________________________________________________ M. Nagasawa(1), E. Thommes(2), & D. N. C. Lin(1) (1)UCSC (2)CITA, University of Toronto Final accretion of terrestrial planets and depletion of asteroids We calculated the orbital evolution of protoplanets and planetesimals during the protoplanetary disk depletion including effects of the tidal drag and gas drag. The estimated total mass in the asteroid belt inferred from observations is only 0.1% of that from the mass distribution of the minimum mass solar nebula. This cannot be accounted for only by planetary configurations. We found a sweeping secular resonance passes through a region of terrestrial planets during the dissipation of disk and that the resonance excites eccentricities of protoplanets and planetesimals and causes their orbits to cross. The excited eccentricities of large protoplanets are damped by the tidal drag and the eccentricities of small particles are damped by gas drag. This damping induces semi-major axes to decay. Therefore, the protoplanets tend to migrate along with the secular resonance and several circular terrestrial planets are formed inside 2AU. Since the effect of the sweeping secular is strong in a region of asteroids, the resonance combined with the tidal drag or gas drag can clear up the asteroids. _____________________________________________________________________ Eric Nielsen (1), Laird Close (1), Rainer Lenzen (2), Jose Guirado (3), Eric Mamajek (4), Wolfgang Brandner (2), Markus Hartung (5), Chris Lidman (5), Beth Biller (1). The First Observational Calibration of Theoretical Cooling Curves for Young, Low-Mass Objects. 1: Steward Observatory, University of Arizona 2: Max-Plank Institut fur Astronomie 3: Departament d'Astronomia i Astrofisica, Universitat de Valencia 4: Harvard-Smithsonian Center for Astrophysics 5: European Southern Observatory Simultaneous Differential Imaging (SDI) is a promising technique to image low-mass, close companions, and our team is undertaking a survey to detect extrasolar planets around a sample of nearby, young stars. Using NACO SDI at the VLT, we have detected a new low-mass companion, 5.4 magnitudes fainter at H than the primary, at a separation of just 0.156 arcseconds. Follow-up JHK photometry gives absolute magnitudes for the new companion of J=9.89 (+0.19, -0.24), H=9.19 (+0.13, -0.15), and Ks=8.57 (+0.12, -0.15), and K-band spectra give a spectral type of M8 (+/- 1.0). From these values, combined with the age of the primary of 50 Myr, and a mass derived from an astrometric orbit of 0.090 (+/- 0.005) solar masses, it is clear that the currently used models (Burrows et al. 2001 and Chabrier et al. 2000) systematically underestimate the mass of young, low-mass objects by about a factor of two. This is a profound result, as young, cool objects may have higher masses than have been reported, and it's likely that "cluster planets," young free-floating objects of planetary mass, are actually just low-mass brown dwarfs. _____________________________________________________________________ Keith Noll (STScI) Binary Planetesimals in Debris Disks The Solar System?s Kuiper Belt is the only debris disk where individual planetesimals in the disk can be studied directly. An understanding of the dynamical history of the Kuiper Belt provides a window into the late stages of giant planet formation and the concomitant clearing retain signatures of the younger, denser protoplanetary disk. One such signature is the remarkably high number of binary objects that have survived to the present era. The largest, high angular resolution, homogeneous survey of the Kuiper