Bo Ma, University of FloridaFollow
Jian Ge, University of FloridaFollow
Alex Wolszczan, Pennsylvania State UniversityFollow
Matthew W. Muterspaugh, Tennessee State UniversityFollow
Brian Lee, University of FloridaFollow
Gregory W. Henry, Tennessee State UniversityFollow
Donald P. Schneider, Pennsylvania State UniversityFollow
Eduardo L. Martín, Centro de AstrobiologíaFollow
Andrzej Niedzielski, Nicolaus Copernicus University in ToruńFollow
Jiwei Xie, University of FloridaFollow
Scott W. Fleming, Space Telescope Science InstituteFollow
Neil Thomas, University of FloridaFollow
Michael Williamson, Tennessee State UniversityFollow
Zhaohuan Zhu, Princeton UniversityFollow
Eric Agol, University of WashingtonFollow
Dmitry Bizyaev, Apache Point Observatory and New Mexico State UniversityFollow
Luiz Nicolaci da Costa, Laboratŕio Interinstitucional de e-AstronomiaFollow
Peng Jiang, University of FloridaFollow
Aldo Fabricio Martinez Fiorenzano, Fundación Galileo Galilei-INAFFollow
Jonay I. González Hernández, Instituto de Astrofísica de CanariasFollow
Pengcheng Guo, University of FloridaFollow
Nolan Grieves, University of FloridaFollow
Rui Li, University of FloridaFollow
Jane Liu, University of FloridaFollow
Suvrath Mahadevan, Pennsylvania State UniversityFollow
Tsevi Mazeh, Tel Aviv UniversityFollow
Duy Cuong Nguyen, University of TorontoFollow
Martin Paegert, Vanderbilt UniversityFollow
Sirinrat Sithajan, University of FloridaFollow
Keivan Stassun, Vanderbilt UniversityFollow
Sivarani Thirupathi, University of FloridaFollow
Julian C. van Eyken, University of California, Santa BarbaraFollow
Xiaoke Wan, University of FloridaFollow
Ji Wang, Yale UniversityFollow
John P. Wisniewski, University of OklahomaFollow
Bo Zhao, University of FloridaFollow
Shay Zucker, Tel Aviv UniversityFollow

Document Type


Publication Date



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 ${T}_{\mathrm{eff}}$ = 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 ${M}_{\mathrm{Jup}}$ and 57.0 ± 3.7 ${M}_{\mathrm{Jup}}$. 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.

Available for download on Saturday, January 01, 2022