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Published October 2015 | Published + Submitted
Journal Article Open

Know the Star, Know the Planet. V. Characterization of the Stellar Companion to the Exoplanet Host HD 177830


HD 177830 is an evolved K0IV star with two known exoplanets. In addition to the planetary companions it has a late-type stellar companion discovered with adaptive optics imagery. We observed the binary star system with the PHARO near-IR camera and the Project 1640 coronagraph. Using the Project 1640 coronagraph and integral field spectrograph we extracted a spectrum of the stellar companion. This allowed us to determine that the spectral type of the stellar companion is a M4±1V. We used both instruments to measure the astrometry of the binary system. Combining these data with published data, we determined that the binary star has a likely period of approximately 800 years with a semi-major axis of 100-200 AU. This implies that the stellar companion has had little or no impact on the dynamics of the exoplanets. The astrometry of the system should continue to be monitored, but due to the slow nature of the system, observations can be made once every 5-10 years.

Additional Information

© 2015 The American Astronomical Society. Received 2015 June 10; accepted 2015 July 28; published 2015 September 8. A portion of 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 (NASA). This work was partially funded through the NASA ROSES Origins of Solar Systems Grant NMO710830/102190. Project 1640 is funded by National Science Foundation grants AST-0520822, AST-0804417, and AST-0908484. The members of the Project 1640 team are also grateful for support from the Cordelia Corporation, Hilary and Ethel Lipsitz, the Vincent Astor Fund, Judy Vale, Andrew Goodwin, and an anonymous donor. C. B. acknowledges support from the Alfred P. Sloan Foundation. We thank the staff of the Palomar Observatory for their invaluable assistance in collecting these data. This paper is based on observations obtained at the Hale Telescope, Palomar Observatory. 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 and NASA's Astrophysics Data System. Facilities: Hale (PHARO - Palomar Observatory's 5.1m Hale Telescope, Project 1640) -

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Published - Roberts_2015p103.pdf

Submitted - 1507.07913v2.pdf


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