KNOW THE STAR, KNOW THE PLANET. III. DISCOVERY OF LATE-TYPE COMPANIONS TO TWO EXOPLANET HOST STARS

We discuss two multiple star systems that host known exoplanets: HD 2638 and 30 Ari B. Adaptive optics imagery revealed an additional stellar companion to both stars. We collected multi-epoch images of the systems with Robo-AO and the PALM-3000 adaptive optics systems at Palomar Observatory and provide relative photometry and astrometry. The astrometry indicates that the companions share common proper motion with their respective primaries. Both of the new companions have projected separations less than 30 AU from the exoplanet host star. Using the projected separations to compute orbital periods of the new stellar companions, HD 2638 has a period of 130 yrs and 30 Ari B has a period of 80 years. Previous studies have shown that the true period is most likely within a factor of three of these estimated values. The additional component to the 30 Ari makes it the second confirmed quadruple system known to host an exoplanet. HD 2638 hosts a hot Jupiter and the discovery of a new companion strengthens the connection between hot Jupiters and binary stars. We place the systems on a color-magnitude diagram and derive masses for the companions which turn out to be roughly 0.5 solar mass stars.

[1]  K. Cunha,et al.  DETAILED ABUNDANCES OF THE SOLAR TWINS 16 CYGNI A AND B: CONSTRAINING PLANET FORMATION MODELS , 2011, 1107.3183.

[2]  M. Hartung,et al.  COMPANIONS TO NEARBY STARS WITH ASTROMETRIC ACCELERATION. II , 2013, 1304.8003.

[3]  Brian D. Mason,et al.  The 2001 US Naval Observatory Double Star CD-ROM. II. The Fifth Catalog of Orbits of Visual Binary Stars , 2001 .

[4]  Bernhard R. Brandl,et al.  PHARO: A Near‐Infrared Camera for the Palomar Adaptive Optics System , 2001 .

[5]  Jena,et al.  Extrasolar planets in stellar multiple systems , 2012, 1204.4833.

[6]  Andrei Tokovinin,et al.  FROM BINARIES TO MULTIPLES. II. HIERARCHICAL MULTIPLICITY OF F AND G DWARFS , 2014, 1401.6827.

[7]  C. Baranec,et al.  PALM-3000: EXOPLANET ADAPTIVE OPTICS FOR THE 5 m HALE TELESCOPE , 2013, 1309.1216.

[8]  Warren R. Brown,et al.  Kepler-16: A Transiting Circumbinary Planet , 2011, Science.

[9]  Pravin Chordia,et al.  HIGH-EFFICIENCY AUTONOMOUS LASER ADAPTIVE OPTICS , 2014, 1407.8179.

[10]  S. Udry,et al.  Tertiary Companions to Close Spectroscopic Binaries , 2006, astro-ph/0601518.

[11]  Bruce W. Carney,et al.  A Survey of Proper-Motion Stars. XVI. Orbital Solutions for 171 Single-lined Spectroscopic Binaries , 2002 .

[12]  L. Roberts,et al.  KNOW THE STAR, KNOW THE PLANET. I. ADAPTIVE OPTICS OF EXOPLANET HOST STARS , 2011, 1109.4320.

[13]  E. Shaya,et al.  VERY WIDE BINARIES AND OTHER COMOVING STELLAR COMPANIONS: A BAYESIAN ANALYSIS OF THE HIPPARCOS CATALOGUE , 2010, 1007.0425.

[14]  Ben R. Oppenheimer,et al.  Adaptive Optics Photometry and Astrometry of Binary Stars , 2005 .

[15]  S. Desidera,et al.  The frequency of planets in multiple systems , 2007, astro-ph/0703754.

[16]  M. Nagasawa,et al.  Formation of Hot Planets by a Combination of Planet Scattering, Tidal Circularization, and the Kozai Mechanism , 2008, 0801.1368.

[17]  Michel Mayor,et al.  The impact of stellar duplicity on planet occurrence and properties. I. Observational results of a V , 2007 .

[18]  F. Fekel,et al.  The properties of close multiple stars , 1981 .

[19]  E. al.,et al.  The Sloan Digital Sky Survey: Technical summary , 2000, astro-ph/0006396.

[20]  S. Tremaine,et al.  Submitted to ApJ Preprint typeset using L ATEX style emulateapj v. 10/09/06 SHRINKING BINARY AND PLANETARY ORBITS BY KOZAI CYCLES WITH TIDAL FRICTION , 2022 .

[21]  Y. Lithwick,et al.  SECULAR CHAOS AND THE PRODUCTION OF HOT JUPITERS , 2010, 1012.3475.

[22]  F. Rasio,et al.  submitted to ApJ Preprint typeset using L ATEX style emulateapj v. 10/09/06 PLANETARY SYSTEMS IN BINARIES. I. DYNAMICAL CLASSIFICATION , 2022 .

[23]  Andrei Tokovinin,et al.  SPECKLE INTERFEROMETRY AT THE BLANCO AND SOAR TELESCOPES IN 2008 AND 2009 , 2009, 0911.5718.

[24]  F. Faedi,et al.  On the abundance of circumbinary planets , 2014, 1404.5617.

[25]  Yanqin Wu,et al.  HOT JUPITERS IN BINARY STAR SYSTEMS , 2007 .

[26]  N. Murray,et al.  Planet Migration and Binary Companions: The Case of HD 80606b , 2003, astro-ph/0303010.

[27]  G. Duchêne.  PLANET FORMATION IN BINARY SYSTEMS: A SEPARATION-DEPENDENT MECHANISM? , 2009, 0912.3025.

[28]  S. Zucker,et al.  On the Mass-Period Correlation of the Extrasolar Planets , 2002, astro-ph/0202415.

[29]  P. Bodenheimer,et al.  Orbital migration of the planetary companion of 51 Pegasi to its present location , 1996, Nature.

[30]  R. Rafikov.  PLANET FORMATION IN SMALL SEPARATION BINARIES: NOT SO SECULARLY EXCITED BY THE COMPANION , 2012, 1212.1465.

[31]  C. Moutou,et al.  The HARPS search for southern extra-solar planets. IV. Three close-in planets around HD 2638, HD 27894 and HD 63454 , 2005 .

[32]  Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems , 2006, astro-ph/0603836.

[33]  C. Morbey,et al.  A SEARCH FOR SPECTROSCOPIC BINARIES FROM PUBLISHED RADIAL VELOCITY DATA , 1974 .

[34]  S. S. Olivier,et al.  Stellar Companions to Stars with Planets , 2002, astro-ph/0207538.

[35]  M. Mugrauer,et al.  A lucky imaging multiplicity study of exoplanet host stars , 2012, 1202.4586.

[36]  G. Chauvin,et al.  Planetary systems in close binary stars: the case of HD 196885 - Combined astrometric and radial velocity study , 2011 .

[37]  A. Tokovinin.  FROM BINARIES TO MULTIPLES. I. DATA ON F AND G DWARFS WITHIN 67 pc OF THE SUN , 2014, 1401.6825.

[38]  Megan E. Schwamb,et al.  PLANET HUNTERS: A TRANSITING CIRCUMBINARY PLANET IN A QUADRUPLE STAR SYSTEM , 2012, 1210.3612.

[39]  L. Roberts,et al.  Binary Star Differential Photometry Using the Adaptive Optics System at Mount Wilson Observatory , 2000 .

[40]  W. Farr,et al.  ON THE FORMATION OF HOT JUPITERS IN STELLAR BINARIES , 2012, 1206.3529.

[41]  Massimiliano Esposito,et al.  A substellar component orbiting the F-star 30 Arietis B , 2009 .

[42]  W. Kley,et al.  Planet formation in binary stars: the case of γ Cephei , 2008, 0805.1354.

[43]  N. I. Shatskii,et al.  A test of Hipparcos parallaxes on multiple stars , 1998 .

[44]  Eric B. Ford,et al.  Dynamical Outcomes of Planet-Planet Scattering , 2007, astro-ph/0703166.

[45]  Chun-Hwey Kim,et al.  THE sdB+M ECLIPSING SYSTEM HW VIRGINIS AND ITS CIRCUMBINARY PLANETS , 2008, 0811.3807.

[46]  S. DesideraM. Barbieri.  Properties of planets in binary systems - The role of binary separation , 2007 .

[47]  F. V. Leeuwen.  Validation of the new Hipparcos reduction , 2007, 0708.1752.

[48]  A. Tokovinin,et al.  WIDE COMPANIONS TO HIPPARCOS STARS WITHIN 67 pc OF THE SUN , 2012, 1208.0626.

[49]  L. Roberts,et al.  KNOW THE STAR, KNOW THE PLANET. II. SPECKLE INTERFEROMETRY OF EXOPLANET HOST STARS , 2011, 1109.4569.

[50]  Harold A. McAlister,et al.  Differential Binary Star Photometry Using the Adaptive Optics System at Starfire Optical Range , 1996 .

[51]  Sujit Punnadi,et al.  A SURVEY OF THE HIGH ORDER MULTIPLICITY OF NEARBY SOLAR-TYPE BINARY STARS WITH Robo-AO , 2014, 1411.0682.

[52]  Wilhelm Kley,et al.  Modeling circumbinary planets: The case of Kepler-38 , 2014, 1401.7648.

[53]  Darko Jevremovic,et al.  The Dartmouth Stellar Evolution Database , 2008, 0804.4473.