THE CALIFORNIA PLANET SURVEY. III. A POSSIBLE 2:1 RESONANCE IN THE EXOPLANETARY TRIPLE SYSTEM HD 37124

We present new radial velocities from Keck Observatory and both Newtonian and Keplerian solutions for the triple-planet system orbiting HD 37124. The orbital solution for this system has improved dramatically since the third planet was first reported in Vogt et al. with an ambiguous orbital period. The period ambiguity is resolved, and the outer two planets have an apparent period commensurability of 2:1. A dynamical analysis finds both resonant and non-resonant configurations consistent with the radial velocity data and constrains the mutual inclinations of the planets to be <~30°. We discuss HD 37124 in the context of the other 19 exoplanetary systems with apparent period commensurabilities, which we summarize in a table. We show that roughly one in three well-characterized multiplanet systems has a apparent low-order period commensurability, which is more than would naively be expected if the periods of exoplanets in known multiplanet systems were drawn randomly from the observed distribution of planetary orbital periods.

[1]  M. Couture,et al.  HIRES: the high-resolution echelle spectrometer on the Keck 10-m Telescope , 1994, Astronomical Telescopes and Instrumentation.

[2]  Ji-lin Zhou,et al.  ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. II. A SATURN–JUPITER CONFIGURATION , 2010, 1007.4520.

[3]  Krzysztof Gozdziewski,et al.  On the Extrasolar Multiplanet System around HD 160691 , 2006, astro-ph/0608279.

[4]  S. Peale,et al.  Secular Evolution of Hierarchical Planetary Systems , 2002, astro-ph/0304454.

[5]  Debra A. Fischer,et al.  A Bayesian Periodogram Finds Evidence for Three Planets in 47 Ursae Majoris , 2010, 1003.5549.

[6]  Migration and the Formation of Systems of Hot Super-Earths and Neptunes , 2006, astro-ph/0609779.

[7]  A. Wolszczan,et al.  Confirmation of Earth-Mass Planets Orbiting the Millisecond Pulsar PSR B1257 + 12 , 1994, Science.

[8]  R. P. Butler,et al.  ATTAINING DOPPLER PRECISION OF 3 M S-1 , 1996 .

[9]  Jason T. Wright,et al.  Five New Extrasolar Planets , 2005 .

[10]  N. Gorelick,et al.  Mean Motion Resonances from Planet-Planet Scattering , 2008, 0809.3449.

[11]  P. Goldreich,et al.  An Explanation of the Frequent Occurrence of Commensurable Mean Motions in the Solar System , 1965 .

[12]  A. Lagrange,et al.  Extrasolar planets and brown dwarfs around A–F type stars - V. A planetary system found with HARPS around the F6IV–V star HD 60532 , 2008, 0809.3862.

[13]  C. G. Tinney,et al.  Four New Exoplanets and Hints of Additional Substellar Companions to Exoplanet Host Stars , 2007 .

[14]  S. Lucatello,et al.  Extrasolar Planets in Multi-Body Systems: Theory and Observations , 2010 .

[15]  Austin,et al.  KEPLER'S FIRST ROCKY PLANET: KEPLER-10b , 2011, 1102.0605.

[16]  R. Paul Butler,et al.  THE LICK-CARNEGIE EXOPLANET SURVEY: A URANUS-MASS FOURTH PLANET FOR GJ 876 IN AN EXTRASOLAR LAPLACE CONFIGURATION , 2010, 1006.4244.

[17]  Wojciech Borczyk,et al.  The long-term stability of extrasolar system HD 37124. Numerical study of resonance effects , 2007 .

[18]  E. Szuszkiewicz,et al.  Jupiter and Super-Earth embedded in a gaseous disc , 2007, 0712.3250.

[19]  K. Tsiganis,et al.  Stable Chaos versus Kirkwood Gaps in the Asteroid Belt: A Comparative Study of Mean Motion Resonances , 2002 .

[20]  E. Chiang,et al.  A Signature of Planetary Migration: The Origin of Asymmetric Capture in the 2:1 Resonance , 2004, astro-ph/0410086.

[21]  F. Fressin,et al.  FIVE KEPLER TARGET STARS THAT SHOW MULTIPLE TRANSITING EXOPLANET CANDIDATES , 2010, 1006.2763.

[22]  Jason T. Wright,et al.  THE CALIFORNIA PLANET SURVEY. I. FOUR NEW GIANT EXOPLANETS , 2010, 1003.3488.

[23]  A. Howard,et al.  EFFICIENT FITTING OF MULTIPLANET KEPLERIAN MODELS TO RADIAL VELOCITY AND ASTROMETRY DATA , 2009, 0904.3725.

[24]  R. Paul Butler,et al.  The 2:1 Resonant Exoplanetary System Orbiting HD 73526 , 2006, astro-ph/0602557.

[25]  Z. Sándor,et al.  Stability and formation of the resonant system HD 73526 , 2007, 0706.2128.

[26]  K. Tsiganis,et al.  Chaotic capture of Jupiter's Trojan asteroids in the early Solar System , 2005, Nature.

[27]  John Asher Johnson,et al.  TEN NEW AND UPDATED MULTIPLANET SYSTEMS AND A SURVEY OF EXOPLANETARY SYSTEMS , 2008, 0812.1582.

[28]  J. Lissauer,et al.  Resonant Inclination Excitation of Migrating Giant Planets , 2003, astro-ph/0308112.

[29]  K. Goździewski.  A dynamical analysis of the HD 37124 planetary system , 2003 .

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

[31]  Naoj,et al.  The Librating Companions in HD 37124, HD 12661, HD 82943, 47 Ursa Majoris, and GJ 876: Alignment or Antialignment? , 2003, astro-ph/0305448.

[32]  Sean N. Raymond,et al.  PLANET–PLANET SCATTERING IN PLANETESIMAL DISKS , 2009, 0905.3741.

[33]  E. Ford,et al.  SECULAR EVOLUTION OF HD 12661: A SYSTEM CAUGHT AT AN UNLIKELY TIME , 2008, 0811.0001.

[34]  R. Paul Butler,et al.  Seven New Keck Planets Orbiting G and K Dwarfs , 2003 .

[35]  R. Paul Butler,et al.  Evidence for Multiple Companions to υ Andromedae , 1999 .

[36]  J. Valenti,et al.  THE NASA-UC ETA-EARTH PROGRAM. I. A SUPER-EARTH ORBITING HD 7924 , 2009, 0901.4394.

[37]  Howard Isaacson,et al.  Kepler-9: A System of Multiple Planets Transiting a Sun-Like Star, Confirmed by Timing Variations , 2010, Science.

[38]  J. Wright.  A Survey of Multiple Planet Systems , 2009, 0909.0957.

[39]  O. Tamuz,et al.  The HARPS search for southern extra-solar planets. VIII. μ Arae , a system with four planets , 2006, astro-ph/0608396.

[40]  J. Papaloizou,et al.  The dynamical origin of the multi-planetary system HD 45364 , 2009, 0910.5082.

[41]  A. Vienne,et al.  THE ROLE OF SECONDARY RESONANCES IN THE EVOLUTION OF THE MIMAS-TETHYS SYSTEM , 1999 .

[42]  J. Wright,et al.  Radial velocity jitter in stars from the california and carnegie planet search at keck observatory , 2005 .

[43]  A. Vienne,et al.  Chaos and secondary resonances in the mimas–tethys system , 1999 .

[44]  J. Laskar,et al.  The CORALIE survey for southern extra-solar planets - XIII. A pair of planets around HD 202206 or a circumbinary planet? , 2005 .

[45]  C. G. Tinney,et al.  Catalog of nearby exoplanets , 2006 .

[46]  J. Laskar,et al.  HD60532, a planetary system in a 3:1 mean motion resonance , 2009, 0902.0667.

[47]  K. Tsiganis,et al.  Origin of the cataclysmic Late Heavy Bombardment period of the terrestrial planets , 2005, Nature.

[48]  Michel Mayor,et al.  The HARPS search for southern extra-solar planets - XVI. HD 45364, a pair of planets in a 3:2 mean motion resonance , 2009 .

[49]  M. López-Morales,et al.  HOW ECCENTRIC ORBITAL SOLUTIONS CAN HIDE PLANETARY SYSTEMS IN 2:1 RESONANT ORBITS , 2008, 0809.1275.

[50]  Howard Isaacson,et al.  Five Planets Orbiting 55 Cancri , 2007, 0712.3917.

[51]  F. Bouchy,et al.  The HARPS survey for southern extra-solar planets. II. A 14 Earth-masses exoplanet around μ Arae , 2004, astro-ph/0408471.

[52]  J. Valenti,et al.  Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs , 2005 .

[53]  Maciej Konacki,et al.  Orbital configurations and dynamical stability of multiplanet systems around sun-like stars HD 202206, 14 Herculis, HD 37124, and HD 108874 , 2006 .

[54]  K. Tsiganis,et al.  Trapping in high-order orbital resonances and inclination excitation in extrasolar systems , 2009 .

[55]  R. Paul Butler,et al.  On the 2:1 Orbital Resonance in the HD 82943 Planetary System , 2005 .

[56]  Ji-lin Zhou,et al.  ON THE ORBITAL EVOLUTION OF A GIANT PLANET PAIR EMBEDDED IN A GASEOUS DISK. I. JUPITER–SATURN CONFIGURATION , 2010, 1002.2201.

[57]  R. Malhotra,et al.  Resonant orbital evolution in the putative planetary system of PSR1257 + 12 , 1992, Nature.

[58]  Chaotic Diffusion And Effective Stability of Jupiter Trojans , 2005 .

[59]  On the migration-induced resonances in a system of two planets with masses in the Earth mass range , 2005, astro-ph/0507611.

[60]  R. Malhotra.  A Dynamical Mechanism for Establishing Apsidal Resonance , 2002, astro-ph/0207126.

[61]  On the Plutinos and Twotinos of the Kuiper Belt , 2002, astro-ph/0210440.

[62]  J. Papaloizou,et al.  On the dynamics of multiple systems of hot super-Earths and Neptunes: tidal circularization, resonance and the HD 40307 system , 2010, 1002.2125.

[63]  K. Tsiganis,et al.  Origin of the orbital architecture of the giant planets of the Solar System , 2005, Nature.

[64]  J. Papaloizou,et al.  On the evolution of mean motion resonances through stochastic forcing: fast and slow libration modes and the origin of HD 128311 , 2008, 0811.1813.

[65]  J. Chambers.  A hybrid symplectic integrator that permits close encounters between massive bodies , 1999 .

[66]  E. Ford,et al.  SECULAR ORBITAL DYNAMICS OF HIERARCHICAL TWO-PLANET SYSTEMS , 2010, 1004.1421.

[67]  D. Queloz,et al.  The CORALIE survey for southern extra-solar planets. XII. Orbital solutions for 16 extra-solar planets discovered with CORALIE , 2003, astro-ph/0310316.

[68]  F. Bouchy,et al.  The HARPS search for southern extra-solar planets: XVIII. An Earth-mass planet in the GJ 581 planetary system , 2009, 0906.2780.

[69]  Debra A. Fischer,et al.  RETIRED A STARS AND THEIR COMPANIONS. VI. A PAIR OF INTERACTING EXOPLANET PAIRS AROUND THE SUBGIANTS 24 SEXTANIS AND HD 200964 , 2010, 1007.4552.

[70]  J. Lissauer,et al.  Saturn’s wayward shepherds: the peregrinations of Prometheus and Pandora , 2003 .

[71]  R. Nelson,et al.  Constraints on resonant-trapping for two planets embedded in a protoplanetary disc , 2008, 0802.2033.

[72]  Eric B. Ford,et al.  Planet–planet scattering in the upsilon Andromedae system , 2005, Nature.

[73]  D. Lin,et al.  Dynamical Shake-up of Planetary Systems. I. Embryo Trapping and Induced Collisions by the Sweeping Secular Resonance and Embryo-Disk Tidal Interaction , 2005 .

[74]  Resonance in PSR B1257+12 Planetary System , 1998, astro-ph/9804096.

[75]  R. Paul Butler,et al.  Five New Multicomponent Planetary Systems , 2005 .

[76]  J. Lissauer,et al.  A ~7.5 M⊕ Planet Orbiting the Nearby Star, GJ 876* , 2005, astro-ph/0510508.

[77]  Evolution of planetary systems in resonance , 2003, astro-ph/0310321.

[78]  Planetary migration and extrasolar planets in the 2/1 mean-motion resonance , 2004, astro-ph/0404166.

[79]  Sean N. Raymond,et al.  PLANET–PLANET SCATTERING IN PLANETESIMAL DISKS. II. PREDICTIONS FOR OUTER EXTRASOLAR PLANETARY SYSTEMS , 2010, 1001.3409.

[80]  K. Ulaczyk,et al.  Discovery of a Jupiter/Saturn Analog with Gravitational Microlensing , 2008, Science.

[81]  J. Brandt,et al.  New horizons in astronomy , 1972 .

[82]  E. Szuszkiewicz,et al.  A Super‐Earth caught in a trap , 2009, 0905.2298.

[83]  D. Frail,et al.  A planetary system around the millisecond pulsar PSR1257 + 12 , 1992, Nature.