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Know the Star, Know the Planet. IV. A Stellar Companion to the Host Star of the Eccentric Exoplanet HD 8673b

Roberts, Lewis C., Jr. and Mason, Brian D. and Neyman, Christopher R. and Wu, Yanqin and Riddle, Reed L. and Shelton, J. Christopher and Angione, John and Baranec, Christoph and Bouchez, Antonin and Bui, Khanh and Burruss, Rick and Burse, Mahesh and Chordia, Pravin and Croner, Ernest and Das, Hillol and Dekany, Richard G. and Guiwits, Stephen and Hale, David and Henning, John and Kulkarni, Shrinivas and Law, Nicholas M. and McKenna, Dan and Milburn, Jennifer and Palmer, Dean and Punnadi, Sujit and Ramaprakash, A. N. and Roberts, Jennifer E. and Tendulkar, Shriharsh P. and Trinh, Thang and Troy, Mitchell and Truong, Tuan and Zolkower, Jeff (2015) Know the Star, Know the Planet. IV. A Stellar Companion to the Host Star of the Eccentric Exoplanet HD 8673b. Astronomical Journal, 149 (4). Art. No. 144. ISSN 1538-3881. doi:10.1088/0004-6256/149/4/144.

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HD 8673 hosts a massive exoplanet in a highly eccentric orbit (e = 0.723). Based on two epochs of speckle interferometry a previous publication identified a candidate stellar companion. We observed HD 8673 multiple times with the 10 m Keck II telescope, the 5 m Hale telescope, the 3.63 m Advanced Electro-Optical System telescope, and the 1.5 m Palomar telescope in a variety of filters with the aim of confirming and characterizing the stellar companion. We did not detect the candidate companion, which we now conclude was a false detection, but we did detect a fainter companion. We collected astrometry and photometry of the companion on six epochs in a variety of filters. The measured differential photometry enabled us to determine that the companion is an early M dwarf with a mass estimate of 0.33–0.45 M⊙. The companion has a projected separation of 10 AU, which is one of the smallest projected separations of an exoplanet host binary system. Based on the limited astrometry collected, we are able to constrain the orbit of the stellar companion to a semimajor axis of 35–60 AU, an eccentricity ⩽0.5, and an inclination of 75°–85°. The stellar companion has likely strongly influenced the orbit of the exoplanet and quite possibly explains its high eccentricity.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Roberts, Lewis C., Jr.0000-0003-3892-2900
Riddle, Reed L.0000-0002-0387-370X
Shelton, J. Christopher0000-0001-8982-1654
Baranec, Christoph0000-0002-1917-9157
Dekany, Richard G.0000-0002-5884-7867
Kulkarni, Shrinivas0000-0001-5390-8563
Law, Nicholas M.0000-0001-9380-6457
Tendulkar, Shriharsh P.0000-0003-2548-2926
Additional Information:© 2015. The American Astronomical Society. Received 2014 June 20. Accepted 2015 February 25. Published 2015 March 30. The research in this paper was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. This paper is based on observations from a number of observatories, including the Maui Space Surveillance System, operated by the US Air Force Research Laboratory's Directed Energy Directorate. Additional observations were made at the Hale Telescope, Palomar Observatory as part of a continuing collaboration between the California Institute of Technology, NASA/JPL, NOAO, Oxford University, Stony Brook University, and the National Astronomical Observatories of China. Some of the data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The W.M. Keck Observatory was made possible by the generous financial support of the W.M. Keck Foundation. The Robo-AO system is supported by collaborating partner institutions, the California Institute of Technology and the Inter-University Centre for Astronomy and Astrophysics, by the National Science Foundation under grant Nos. AST-0906060, AST-0960343, and AST-1207891, by a grant from the Mt. Cuba Astronomical Foundation and by a gift from Samuel Oschin. C.B. acknowledges support from the Alfred P. Sloan Foundation. This research made use of the Washington Double Star Catalog maintained at the U.S. Naval Observatory, the SIMBAD database, operated by the CDS in Strasbourg, France, NASA's Astrophysics Data System and data products from the 2MASS, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. Facilities: AEOS (Visible Imager), Hale (PHARO), Keck:II (NIRC2), PO:1.5 m (Robo-AO).
Group:Seismological Laboratory, Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Inter-University Centre for Astronomy and AstrophysicsUNSPECIFIED
Mt. Cuba Astronomical FoundationUNSPECIFIED
Alfred P. Sloan FoundationUNSPECIFIED
Subject Keywords:binaries: visual; instrumentation: adaptive optics; stars: individual (HD 8673) ; stars: late-type
Issue or Number:4
Record Number:CaltechAUTHORS:20160613-133245263
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Official Citation:Lewis C. Roberts Jr. et al 2015 The Astronomical Journal 149 144
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:67882
Deposited By: George Porter
Deposited On:13 Jun 2016 21:15
Last Modified:11 Nov 2021 03:56

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