KELT-2Ab: A Hot Jupiter Transiting the Bright (V=8.77) Primary Star of a Binary System

Дата и время публикации : 2012-06-07T20:00:00Z

Авторы публикации и институты :
Thomas G. Beatty
Joshua Pepper
Robert J. Siverd
Jason D. Eastman
Allyson Bieryla
David W. Latham
Lars A. Buchhave
Eric L. N. Jensen
Mark Manner
Keivan G. Stassun
B. Scott Gaudi
Perry Berlind
Michael L. Calkins
Karen Collins
Darren L. DePoy
Gilbert A. Esquerdo
Benjamin J. Fulton
Gábor Fürész
John C. Geary
Andrew Gould
Leslie Hebb
John F. Kielkopf
Jennifer L. Marshall
Richard Pogge
K. Z. Stanek
Robert P. Stefanik
Rachel Street
Andrew H. Szentgyorgyi
Mark Trueblood
Patricia Trueblood
Amelia M. Stutz

Ссылка на журнал-издание: Astrophysical Journal Letters 756, L39 (2012)
Коментарии к cтатье: 9 pages, 2 tables, 4 figures. A short video describing this paper is available at Revised to reflect the ApJL version. Note that figure 4 is not in the ApJL version
Первичная категория: astro-ph.EP

Все категории : astro-ph.EP

Краткий обзор статьи: We report the discovery of KELT-2Ab, a hot Jupiter transiting the bright (V=8.77) primary star of the HD 42176 binary system. The host is a slightly evolved late F-star likely in the very short-lived "blue-hook" stage of evolution, with $teff=6148pm48{rm K}$, $log{g}=4.030_{-0.026}^{+0.015}$ and $feh=0.034pm0.78$. The inferred stellar mass is $M_*=1.314_{-0.060}^{+0.063}$msun and the star has a relatively large radius of $R_*=1.836_{-0.046}^{+0.066}$rsun. The planet is a typical hot Jupiter with period $4.11379pm0.00001$ days and a mass of $M_P=1.524pm0.088$mj and radius of $R_P=1.290_{-0.050}^{+0.064}$rj. This is mildly inflated as compared to models of irradiated giant planets at the $sim$4 Gyr age of the system. KELT-2A is the third brightest star with a transiting planet identified by ground-based transit surveys, and the ninth brightest star overall with a transiting planet. KELT-2Ab’s mass and radius are unique among the subset of planets with $V<9$ host stars, and therefore increases the diversity of bright benchmark systems. We also measure the relative motion of KELT-2A and -2B over a baseline of 38 years, robustly demonstrating for the first time that the stars are bound. This allows us to infer that KELT-2B is an early K-dwarf. We hypothesize that through the eccentric Kozai mechanism KELT-2B may have emplaced KELT-2Ab in its current orbit. This scenario is potentially testable with Rossiter-McLaughlin measurements, which should have an amplitude of $sim$44 m s$^{-1}$.

Category: Physics