The Core Accretion Model Predicts Few Jovian-Mass Planets Orbiting Red 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, this Letter presents theoretical calculations that 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.

[1]  R. Paul Butler,et al.  Scientific Frontiers in Research on Extrasolar Planets , 2003 .

[2]  R. Paul Butler,et al.  DETECTION OF EXTRASOLAR GIANT PLANETS , 1998 .

[3]  S. Inaba,et al.  Enhanced collisional growth of a protoplanet that has an atmosphere , 2003 .

[4]  R. P. Butler,et al.  A Transiting “51 Peg-like” Planet , 2000, The Astrophysical journal.

[5]  A. Boss,et al.  Protostars and Planets VI , 2000 .

[6]  J. Harker,et al.  Detection of Intermediate‐Period Transiting Planets with a Network of Small Telescopes: transitsearch.org , 2003, astro-ph/0310084.

[7]  Dynamics and Origin of the 2:1 Orbital Resonances of the GJ 876 Planets , 2001, astro-ph/0108104.

[8]  Italo Mazzitelli,et al.  New pre-main-sequence tracks for M less than or equal to 2.5 solar mass as tests of opacities and convecti on model , 1994 .

[9]  G. Marcy,et al.  Planetary Companions to the Metal-rich Stars BD –10°3166 and HD 52265* , 2000 .

[10]  A. K. Vivas,et al.  The CIDA-QUEST large-scale survey of Orion OB1: evidence for rapid disk dissipation in a dispersed stellar population. , 2001, Science.

[11]  L. G. Henyey,et al.  A NEW METHOD OF AUTOMATIC COMPUTATION OF STELLAR EVOLUTION , 1964 .

[12]  Jon M. Jenkins,et al.  Kepler: a space mission to detect earth-class exoplanets , 1998, Astronomical Telescopes and Instrumentation.

[13]  U. Gorti,et al.  Photoevaporation of Circumstellar Disks Due to External Far-Ultraviolet Radiation in Stellar Aggregates , 2004, astro-ph/0404383.

[14]  A. Boss,et al.  Possible Rapid Gas Giant Planet Formation in the Solar Nebula and Other Protoplanetary Disks , 2000, The Astrophysical journal.

[15]  S. Inaba,et al.  Formation of gas giant planets: core accretion models with fragmentation and planetary envelope , 2003 .

[16]  R. Paul Butler,et al.  A Pair of Resonant Planets Orbiting GJ 876 , 2001 .

[17]  H. Richer,et al.  A Young White Dwarf Companion to Pulsar B1620-26: Evidence for Early Planet Formation , 2003, Science.

[18]  CRITICAL PROTOPLANETARY CORE MASSES IN PROTOPLANETARY DISKS AND THE FORMATION OF SHORT-PERIOD GIANT PLANETS , 1999, astro-ph/9903310.

[19]  A. Boss,et al.  Protostars and Planets , 1998, Science.

[20]  F. Adams,et al.  Infrared Spectra of Rotating Protostars , 1986 .

[21]  Astrophysics,et al.  Models of the formation of the planets in the 47 UMa system , 2002, Astronomy & Astrophysics.

[22]  Jack J. Lissauer,et al.  Formation of the Giant Planets by Concurrent Accretion of Solids and Gas , 1995 .

[23]  K. Zebrun,et al.  OGLE 2003-BLG-235/MOA 2003-BLG-53: A Planetary Microlensing Event , 2004 .

[24]  A. Gould,et al.  Statistical Determination of the MACHO Mass Spectrum , 1995, astro-ph/9504078.

[25]  M. Podolak.  The contribution of small grains to the opacity of protoplanetary atmospheres , 2003 .