Bibcode
Ma, B.; Ge, Jian; Wolszczan, Alex; Muterspaugh, Matthew W.; Lee, Brian; Henry, Gregory W.; Schneider, Donald P.; Martín, Eduardo L.; Niedzielski, Andrzej; Xie, Jiwei; Fleming, Scott W.; Thomas, Neil; Williamson, Michael; Zhu, Zhaohuan; Agol, Eric; Bizyaev, Dmitry; Nicolaci da Costa, Luiz; Jiang, Peng; Martinez Fiorenzano, A. F.; González Hernández, J. I.; Guo, Pengcheng; Grieves, Nolan; Li, Rui; Liu, Jane; Mahadevan, Suvrath; Mazeh, Tsevi; Nguyen, Duy Cuong; Paegert, Martin; Sithajan, Sirinrat; Stassun, Keivan; Thirupathi, Sivarani; van Eyken, Julian C.; Wan, Xiaoke; Wang, Ji; Wisniewski, John P.; Zhao, Bo; Zucker, Shay
Bibliographical reference
The Astronomical Journal, Volume 152, Issue 5, article id. 112, 12 pp. (2016).
Advertised on:
11
2016
Citations
17
Refereed citations
15
Description
We report the detections of a giant planet (MARVELS-7b) and a brown
dwarf (BD) candidate (MARVELS-7c) around the primary star in the close
binary system, HD 87646. To the best of our knowledge, it is the first
close binary system with more than one substellar circumprimary
companion that has been discovered. The detection of this giant planet
was accomplished using the first multi-object Doppler instrument
(KeckET) at the Sloan Digital Sky Survey (SDSS) telescope. Subsequent
radial velocity observations using the Exoplanet Tracker at the Kitt
Peak National Observatory, the High Resolution Spectrograph at the Hobby
Eberley telescope, the “Classic” spectrograph at the
Automatic Spectroscopic Telescope at the Fairborn Observatory, and
MARVELS from SDSS-III confirmed this giant planet discovery and revealed
the existence of a long-period BD in this binary. HD 87646 is a close
binary with a separation of ∼22 au between the two stars, estimated
using the Hipparcos catalog and our newly acquired AO image from PALAO
on the 200 inch Hale Telescope at Palomar. The primary star in the
binary, HD 87646A, has {T}{eff} = 5770 ± 80 K, log g
= 4.1 ± 0.1, and [Fe/H] = ‑0.17 ± 0.08. The derived
minimum masses of the two substellar companions of HD 87646A are 12.4
± 0.7 {M}{Jup} and 57.0 ± 3.7
{M}{Jup}. The periods are 13.481 ± 0.001 days and 674
± 4 days and the measured eccentricities are 0.05 ± 0.02
and 0.50 ± 0.02 respectively. Our dynamical simulations show that
the system is stable if the binary orbit has a large semimajor axis and
a low eccentricity, which can be verified with future astrometry
observations.