Development of the CAGC model

Planet formation theories and models have been proposed, debated, and refined for quite a few decades. An overall discussion of planet formation is presented by J. Lissauer in this book, and a brief historical overview of the CAGC model is offered in this section. The earliest theories proposed that planets formed from mass thrown off the Sun after it had condensed into its current state (Descartes 1644 Kant 1755 Laplace 1796 W. Herschel 1811). A rudimentary version of an accretion theory was...

Summary and conclusions

More than 130 stars are now known to harbor planetary systems. The correlation between planetary frequency and metallicity is now well established, and probably reflects nature rather than nurture. We have analyzed the statistical properties of the current sample of ESP hosts, looking for other possible trends and biases. With the possible exception of a higher mean velocity perpendicular to the Plane, the planetary hosts appear to be unremarkable members of the Galactic Disk. Several ESP host...

Introduction

The extremely short orbital period of 51 Pegasi (Mayor & Queloz 1995) and the other hot Jupiters pose a problem for planet formation, not only because such systems bear little resemblance to the Solar System, but more fundamentally because the high temperatures expected in the protoplanetary disk at radii a < 0.1 AU largely preclude the possibility of in situ formation. Disk models by Bell et al. (1997) show that for typical T Tauri accretion rates of M 10 8 Mq yr_1 (Gullbring et al....

Primary transits

The primary transit by an extrasolar planet, in which the planet passes between its parent star and the Earth, is useful for several reasons. The light curves from such transits have been used to estimate gross properties of all of the presently known transiting planets and of their stars, measuring the stellar and planetary radii, the inclination of the planets' orbit, and the strength of limb darkening on the stars. Moreover, for the two nearest transiting planets, more-or-less successful...

A decade of extrasolar planets around normal stars

Proceedings of the Space Telescope Science Institute Symposium, held in Baltimore, Maryland May 2-5, 2005 Space Telescope Science Institute, Baltimore, MD 21218, USA Space Telescope Science Institute, Baltimore, MD 21218, USA Space Telescope Science Institute, Baltimore, MD 21218, USA Published for the Space Telescope Science Institute Cambridge, New York, Melbourne, Madrid, Cape Town, Singapore, Sao Paulo The Edinburgh Building, Cambridge CB2 8RU, UK Published in the United States of America...

Radiative cooling

In pioneering work by Nelson et al. (2000), the midplane temperatures and surface densities from 2D thin-disk hydrodynamics simulations are used to fit simple vertical structures in hydrostatic equilibrium. The vertical fits then permit an estimate of the cooling rate for each column based on realistic opacities. In several simulations of Solar Nebula-sized disks, disk fragmentation, if it occurs at all, is much reduced over isothermal evolutions of the same disks. As an extension of Gammie's...

Photometer and spacecraft description

Schmidt Corrector

The instrument is a wide-FOV differential photometer with a 100 square degree FOV that continuously and simultaneously monitors the brightness of 100,000 main-sequence stars with sufficient precision to detect transits by Earth-size planets orbiting G2 dwarfs. 38 W. J. Borucki et al. The Kepler mission Figure 1. Isometric view of the Kepler photometer. Graphite Cyan ate Metering Structure Figure 1. Isometric view of the Kepler photometer. The brightness range of target stars is from visual...

The potential for planet formation in young circumstellar disks

What are the initial conditions in young disks, and what is the likelihood that they are, in fact, proto-planetary The raw material of planetary embryos, Earth-like rocks, and Jupiter-like gas giants is indeed abundant, if not ubiquitous, in young disks. But whether any individual disk will form planets is, of course, unknowable. What we can say is that many of the disks we observe are at least capable of forming planetary systems similar to our own, as evidenced from measured disk sizes,...

Giant planet formation models

The observation that the mass function of young objects in star-forming regions extends down through the brown dwarf mass range to below the deuterium burning limit Zapatero Osorio et al. 2000 , together with the lack of any convincing theoretical reason to believe that the collapse process that leads to stars cannot also produce substellar . lt 3 g . lt f ' ' 0.5 1.0 1.5 2.0 2.5 0.5 1.0 1.5 2.0 2.5 0.5 1.0 1.5 2.0 2.5 semi-major axis au semi-major axis au semi-major axis au 0.5 1.0 1.5 2.0 2.5...

Questions concerning primordial dust disk evolution

The term primordial is used in reference to disks that are remnants of the star formation process. As outlined above, such disks are composed of the dust and gas which participated in the gravitational collapse that formed the star, and now comprise the raw materials for the formation of planets. The size, mass, and composition parameters of known young primordial disks are consistent with those estimated for the proto-solar system disk. Terrestrial planets and the rocky cores of giant planets...

The CAGC computer model

At the time of this conference, there are four groups that have computer models based on the CAGC formation of gas giant planets the collaborators at NASA-Ames Research Center and University of California at Santa Cruz referred to ARC UCSC group the group in Japan the group in Bern, Switzerland and G. Wuchterl. The first three groups use a similar technique based on a modified stellar structure evolution code, and Wuchterl uses a fully hydrodynamical computer code to model the evolving...

By Olenka Hubickyj

UCO Lick Observatory, University of California, Santa Cruz, CA 94064 and NASA Ames Research Center, MS 245-3, Moffett Field, CA 94035, USA The core accretion-gas capture model is generally accepted as the standard formation model for gas giant planets. It proposes that a solid core grows via the accretion of planetesimals, and then captures a massive envelope from the solar nebula gas. Simulations have been successful in explaining many features of giant planets. This chapter will present an...