Very low mass stellar and substellar companions to solar-like stars from MARVELS. II. A short-period companios orbiting an F star with evidence of a stellar tertiary and significant mutual inclination

Autor: Eric J. Roebuck, Carlos Allende Prieto, Ji Wang, Rafael Rebolo, Gwendolyn M. Weaver, Eric Agol, Louis Coban, Howard Brewington, Joshua Pepper, Duy Cuong Nguyen, Audrey Simmons, Jian Liu, Xiaoke Wan, Daniel Oravetz, Peng Jiang, B. Scott Gaudi, Martin Paegert, Luan Ghezzi, Stephen R. Kane, Elena Malanushenko, W. Michael Wood-Vasey, Nathan De Lee, Rory Barnes, Thomas G. Beatty, Chelsea L. M. Vincent, Bo Ma, Alaina Shelden, John P. Wisniewski, Marcio A. G. Maia, Brian Lee, Jian Ge, Donald P. Schneider, Nelson Hua, Kaike Pan, Jonay I. González Hernández, Stephanie A. Snedden, Demitri Muna, Bo Zhao, B. E. Nelson, Luis N. da Costa, Bruce Gary, Justin R. Crepp, Phillip A. Cargile, Massimiliano Esposito, Benjamin J. Shappee, Dmitry Bizyaev, Suvrath Mahadevan, Leslie Hebb, Benjamin A. Weaver, Korena S. Costello, Bruno Femenia, Keivan G. Stassun, Benjamin M. Tofflemire, Gustavo F. Porto de Mello, Thirupathi Sivarani, Scott W. Fleming, Viktor Malanushenko, Leticia D. Ferreira, Gary R. Lander, Todd A. Thompson, Basilio X. Santiago, Melanie Good
Jazyk: angličtina
Rok vydání: 2012
Předmět:
010504 meteorology & atmospheric sciences
Stellar mass
Astrometria
Momento angular
FOS: Physical sciences
Hidrogênio
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
Compact star
Massa estelar
01 natural sciences
Movimento estelar
spectroscopic [Binaries]
individual (TYC 2930-00872-1) [Stars]
0103 physical sciences
Evolucao estelar
Astrophysics::Solar and Stellar Astrophysics
010303 astronomy & astrophysics
Astrophysics::Galaxy Astrophysics
Solar and Stellar Astrophysics (astro-ph.SR)
0105 earth and related environmental sciences
Physics
Cálcio
Astronomy and Astrophysics
Orbital period
Espectros estelares
Radial velocity
Stars
Astrophysics - Solar and Stellar Astrophysics
Space and Planetary Science
Potássio
Spectral energy distribution
Astrophysics::Earth and Planetary Astrophysics
Low Mass
Dimensões estelares
close [Binaries]
Main sequence
Zdroj: Repositório Institucional da UFRGS
Universidade Federal do Rio Grande do Sul (UFRGS)
instacron:UFRGS
Popis: 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 $P > 2000$ 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 ��, 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 < 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 < 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.
37 pages, 7 tables, 21 figures, Accepted in AJ
Databáze: OpenAIRE
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