Very Low Mass Stellar and Substellar Companions to Solar-like Stars from MARVELS. IV. A Candidate Brown Dwarf or Low-mass Stellar Companion to HIP 67526

September 2013 • 2013AJ....146...65J

Authors • Jiang, Peng • Ge, Jian • Cargile, Phillip • Crepp, Justin R. • De Lee, Nathan • Porto de Mello, Gustavo F. • Esposito, Massimiliano • Ferreira, Letícia D. • Femenia, Bruno • Fleming, Scott W. • Gaudi, B. Scott • Ghezzi, Luan • González Hernández, Jonay I. • Hebb, Leslie • Lee, Brian L. • Ma, Bo • Stassun, Keivan G. • Wang, Ji • Wisniewski, John P. • Agol, Eric • Bizyaev, Dmitry • Brewington, Howard • Chang, Liang • Nicolaci da Costa, Luiz • Eastman, Jason D. • Ebelke, Garrett • Gary, Bruce • Kane, Stephen R. • Li, Rui • Liu, Jian • Mahadevan, Suvrath • Maia, Marcio A. G. • Malanushenko, Viktor • Malanushenko, Elena • Muna, Demitri • Nguyen, Duy Cuong • Ogando, Ricardo L. C. • Oravetz, Audrey • Oravetz, Daniel • Pan, Kaike • Pepper, Joshua • Paegert, Martin • Allende Prieto, Carlos • Rebolo, Rafael • Santiago, Basilio X. • Schneider, Donald P. • Shelden Bradley, Alaina C. • Sivarani, Thirupathi • Snedden, Stephanie • van Eyken, J. C. • Wan, Xiaoke • Weaver, Benjamin A. • Zhao, Bo

Abstract • We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 yr. Our Keplerian fit, using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of 90.2695^{+0.0188}_{-0.0187} days, an eccentricity of 0.4375 ± 0.0040, and a semi-amplitude of 2948.14^{+16.65}_{-16.55} m s^-1. Using additional high-resolution spectroscopy, we find the host star has an effective temperature T _eff = 6004 ± 34 K, a surface gravity log g (cgs) =4.55 ± 0.17, and a metallicity [Fe/H] =+0.04 ± 0.06. The stellar mass and radius determined through the empirical relationship of Torres et al. yields 1.10 ± 0.09 M _⊙ and 0.92 ± 0.19 R _⊙. The minimum mass of MARVELS-5b is 65.0 ± 2.9M _Jup, indicating that it is likely to be either a BD or a very low mass star, thus occupying a relatively sparsely populated region of the mass function of companions to solar-type stars. The distance to this system is 101 ± 10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2 M _⊙ at a separation larger than 40 AU.

Links

• PREPRINT http://arxiv.org/abs/1307.3308
• ELECTR https://iopscience.iop.org/article/10.1088/0004-6256/146/3/65
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2013AJ....146...65J
• PDF https://iopscience.iop.org/article/10.1088/0004-6256/146/3/65/pdf
• DATA https://irsa.ipac.caltech.edu/bibdata/2013/J/2013AJ....146...65J.html