A Substellar Companion to the Intermediate-Mass Giant 11 Com

Abstract

We report the detection of a substellar companion orbiting the intermediate-mass giant star 11 Com (G8 III). Precise Doppler measurements of the star from Xinglong station and Okayama Astrophysical Observatory (OAO) revealed Keplerian velocity variations with an orbital period of 326.03 +/- 0.32 days, a semiamplitude of 302.8 +/- 2.6 m/s, and an eccentricity of 0.231 +/- 0.005. Adopting a stellar mass of 2.7 +/- 0.3 M_solar, the minimum mass of the companion is 19.4 +/- 1.5 M_Jup, well above the deuterium burning limit, and the semimajor axis is 1.29 +/- 0.05 AU. This is the first result from the joint planet search program between China and Japan aiming at revealing statistics of substellar companions around intermediate-mass giants. 11 Com b emerged from 300 targets of the planet search program at OAO. The current detection rate of a brown dwarf candidate seems to be comparable to that around solar-type stars within orbital separations of $\sim$3 AU.

19 pages, 4 figures, accepted by ApJ

References in corpus (14)

• Catalog of Nearby Exoplanets
• The formation and retention of gas giant planets around stars with a range of metallicities
• How Dry is the Brown Dwarf Desert?: Quantifying the Relative Number of Planets, Brown Dwarfs and Stellar Companions around Nearby Sun-like Stars
• Chemical composition of 90 F and G disk dwarfs
• The Y^2 Stellar Evolutionary Tracks
• Retired A Stars and Their Companions: Exoplanets Orbiting Three Intermediate-Mass Subgiants
• Predicting the Properties of Binary Stellar Systems: The Evolution of Accreting Protobinary Systems
• Planets around evolved intermediate-mass stars. I. Two substellar companions in the open clusters NGC 2423 and NGC 4349
• A Planetary Mass Companion to the K0 Giant HD 17092
• Substellar companions and isolated planetary mass objects from protostellar disc fragmentation
• A substellar companion around the intermediate-mass giant star HD 11977
• Fourteen New Companions from the Keck & Lick Radial Velocity Survey Including Five Brown Dwarf Candidates
• Extrasolar planets and brown dwarfs around A-F type stars. IV. A candidate brown dwarf around the A9V pulsating star HD180777
• A brown dwarf desert for intermediate mass stars in Sco OB2?

Cited by in corpus (46)

• The Orbital Evolution of Gas Giant Planets around Giant Stars
• Precise Radial Velocities of Giant Stars VII. Occurrence Rate of Giant Extrasolar Planets as a Function of Mass and Metallicity
• Stellar Parameters and Elemental Abundances of Late-G Giants
• Retired A Stars and Their Companions. III. Comparing the Mass-Period Distributions of Planets Around A-Type Stars and Sun-Like Stars
• Search for brown-dwarf companions of stars
• Extrasolar planets in stellar multiple systems
• The Xinglong 2.16-m Telescope: Current Instruments and Scientific Projects
• Statistical Properties of Brown Dwarf Companions: Implications for Different Formation Mechanisms
• Stellar Diameters and Temperatures V. Eleven Newly Characterized Exoplanet Host Stars
• Planet Engulfment by ~1.5-3 Solar-Mass Red Giants
• Evidence for the Tidal Destruction of Hot Jupiters by Subgiant Stars
• Calibration of Equilibrium Tide Theory for Extrasolar Planet Systems II
• Planetary Companions around Three Intermediate-Mass G and K Giants: 18 Del, xi Aql, and HD 81688
• Mass constraints on substellar companion candidates from the re-reduced Hipparcos intermediate astrometric data: Nine confirmed planets and two confirmed brown dwarfs
• Substellar-mass companions to the K-dwarf BD +14 4559 and the K-giants HD 240210 and BD +20 2457
• Spitzer IRAC Observations of White Dwarfs. II. Massive Planetary and Cold Brown Dwarf Companions to Young and Old Degenerates
• A high binary fraction for the most massive close-in giant planets and brown dwarf desert members
• Substellar-Mass Companions to the K-Giants HD 240237, BD +48 738 and HD 96127
• Planetary Companions to Evolved Intermediate-Mass Stars: 14 Andromedae, 81 Ceti, 6 Lyncis, and HD 167042
• Planetary-mass companions to the K-giants BD+15 2940 and HD 233604
• The lithium abundances for a large sample of red giants
• Substellar Companions to Seven Evolved Intermediate-Mass Stars
• Planetary Companions to Three Evolved Intermediate-Mass Stars: HD 2952, HD 120084, and omega Serpentis
• Precise radial velocities of giant stars XVI. Planet occurrence rates from the combined analysis of the Lick, EXPRESS, and PPPS giant star surveys
• Discovery of the first wide L dwarf + giant binary system and eight other ultra-cool dwarfs in wide binaries
• Substellar Companions to Evolved Intermediate-Mass Stars: HD 145457 and HD 180314
• Three red giants with substellar-mass companions
• Precise radial velocities of giant stars. X. Bayesian stellar parameters and evolutionary stages for 372 giant stars from the Lick planet search
• The Masses of a Sample of Radial-Velocity Exoplanets with Astrometric Measurements
• An eclipsing double-line spectroscopic binary at the stellar/substellar boundary in the Upper Scorpius OB association
• Precise radial velocities of giant stars IX. HD 59686 Ab: a massive circumstellar planet orbiting a giant star in a ~13.6 au eccentric binary system
• A Massive Substellar Companion to the Massive Giant HD 119445
• Precise radial velocities of giant stars VIII. Testing for the presence of planets with CRIRES Infrared Radial Velocities
• A Pair of Giant Planets around the Evolved Intermediate-Mass Star HD 47366: Multiple Circular Orbits or a Mutually Retrograde Configuration
• Precise radial velocities of giant stars. XI. Two brown dwarfs in 6:1 mean motion resonance around the K giant star $\nu$ Ophiuchi
• Radio Emissions from Substellar Companions of Evolved Cool Stars
• OGLE-2019-BLG-1470LABc: Another Microlensing Giant Planet in a Binary System?
• Multiple Populations of Extrasolar Gas Giants
• A Possible Substellar Companion to the Intermediate-mass Giant HD 175679
• Oscillations in the G-type Giants
• Precise radial velocities of giant stars XV. Mysterious nearly periodic radial velocity variations in the eccentric binary $\epsilon$ Cygni
• On the stability of planetary orbits in binary star systems I. The S-type orbits
• Search for Exoplanets around Northern Circumpolar Stars- II. The Detection of Radial Velocity Variations in M Giant Stars HD 36384, HD 52030, and HD 208742
• Precise radial velocities of giant stars -- XVII. Distinguishing planets from intrinsically induced radial velocity signals in evolved stars
• Two close binaries across the hydrogen-burning limit in the Praesepe open cluster
• 3D models of the circumstellar environments of evolved stars: Formation of multiple spiral structures