Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS II: A Short-period Companion Orbiting an F Star with Evidence of a Stellar Tertiary And Significant Mutual Inclination
Creators: name: Fleming, Scott W.
name: Ge, Jian
name: Barnes, Rory
name: Beatty, Thomas G.
name: Crepp, Justin R.
name: De Lee, Nathan
name: Esposito, Massimiliano
name: Femenia, Bruno
name: Ferreira, Leticia
name: Gary, Bruce
name: Gaudi, B. Scott
name: Ghezzi, Luan
name: Hernández, Jonay I. González
name: Hebb, Leslie
name: Jiang, Peng
name: Lee, Brian
name: Nelson, Ben
name: de Mello, Gustavo F. Porto
name: Shappee, Benjamin J.
name: Stassun, Keivan
name: Thompson, Todd A.
name: Tofflemire, Benjamin M.
name: Wisniewski, John P.
name: Wood-Vasey, W. Michael
name: Agol, Eric
name: Prieto, Carlos Allende
name: Bizyaev, Dmitry
name: Brewington, Howard
name: Cargile, Phillip A.
name: Coban, Louis
name: Costello, Korena S.
name: da Costa, Luis N.
name: Good, Melanie L.
name: Hua, Nelson
name: Kane, Stephen R.
name: Lander, Gary R.
name: Liu, Jian
name: Ma, Bo
name: Mahadevan, Suvrath
name: Maia, Marcio A. G.
name: Malanushenko, Elena
name: Malanushenko, Viktor
name: Muna, Demitri
name: Nguyen, Duy Cuong
name: Oravetz, Daniel
name: Paegert, Martin
name: Pan, Kaike
name: Pepper, Joshua
name: Rebolo, Rafael
name: Roebuck, Eric J.
name: Santiago, Basilio X.
name: Schneider, Donald P.
name: Shelden, Alaina
name: Simmons, Audrey
name: Sivarani, Thirupathi
name: Snedden, Stephanie
name: Vincent, Chelsea L. M.
name: Wan, Xiaoke
name: Wang, Ji
name: Weaver, Benjamin A.
name: Weaver, Gwendolyn M.
name: Zhao, Bo
Publisher: name: arXiv
Year: 2012
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We report the discovery via radial velocity of a short-period (P = 2.430420 \pm 0.000006 days) companion to the F-type main sequence star TYC 2930-00872-1. A long-term trend in the radial velocities indicates the presence of a tertiary stellar companion with $P &gt; 2000$ days. High-resolution spectroscopy of the host star yields T_eff = 6427 +/- 33 K, log(g) = 4.52 +/- 0.14, and [Fe/H]=-0.04 +/- 0.05. These parameters, combined with the broad-band spectral energy distribution and parallax, allow us to infer a mass and radius of the host star of M_1=1.21 +/- 0.08 M_\odot and R_1=1.09_{-0.13}^{+0.15} R_\odot. We are able to exclude transits of the inner companion with high confidence. The host star's spectrum exhibits clear Ca H and K core emission indicating stellar activity, but a lack of photometric variability and small v*sin(I) suggest the primary's spin axis is oriented in a pole-on configuration. The rotational period of the primary from an activity-rotation relation matches the orbital period of the inner companion to within 1.5 σ, suggesting they are tidally locked. If the inner companion's orbital angular momentum vector is aligned with the stellar spin axis, as expected through tidal evolution, then it has a stellar mass of M_2 ~ 0.3-0.4 M_\odot. Direct imaging limits the existence of stellar companions to projected separations &lt; 30 AU. No set of spectral lines and no significant flux contribution to the spectral energy distribution from either companion are detected, which places individual upper mass limits of M &lt; 1.0 M_\odot, provided they are not stellar remnants. If the tertiary is not a stellar remnant, then it likely has a mass of ~0.5-0.6 M_\odot, and its orbit is likely significantly inclined from that of the secondary, suggesting that the Kozai-Lidov mechanism may have driven the dynamical evolution of this system.
description: 37 pages, 7 tables, 21 figures, Accepted in AJ