The American Astronomical Society (AAS), established in 1899 and based in Washington, DC, is the major organization of professional astronomers in North America. Its membership of about 7,000 individuals also includes physicists, mathematicians, geologists, engineers, and others whose research and educational interests lie within the broad spectrum of subjects comprising contemporary astronomy. The mission of the AAS is to enhance and share humanity's scientific understanding of the universe.
Two New Candidate Planets in Eccentric Orbits*
Geoffrey W. Marcy,R. Paul Butler,Steven S. Vogt,Debra Fischer, andMichael C. Liu
© 1999. The AmericanAstronomical Society. All rights reserved. Printed inU.S.A.
The Astrophysical Journal,Volume 520,Number 1Citation Geoffrey W. Marcyet al 1999ApJ520 239DOI 10.1086/307451
Geoffrey W. Marcy
AFFILIATIONS
Department of Physics and Astronomy, San Francisco, CA 94132; and Department of Astronomy, University of California, Berkeley, CA 94720
R. Paul Butler
AFFILIATIONS
Anglo-Australian Observatory, P.O. Box 296, Epping, NSW 1710, Australia
Steven S. Vogt
AFFILIATIONS
UCO/Lick Observatory, University of California at Santa Cruz, Santa Cruz, CA, 95064
Debra Fischer
AFFILIATIONS
Department of Physics and Astronomy, San Francisco, CA 94132; and Department of Astronomy, University of California, Berkeley, CA 94720
Michael C. Liu
AFFILIATIONS
Department of Astronomy, University of California at Berkeley, Berkeley, CA 94720
Article metrics
1466 Total downloads
0 Video abstract views
Permissions
Dates
- Received1998 December 16
- Accepted1999 February 24
Abstract
Doppler measurements of two G-type main-sequence stars, HD 210277 and HD 168443, reveal Keplerian variations that imply the presence of companions with masses (M sini) of 1.28 and 5.04MJ (whereMJ is the mass of Jupiter) and orbital periods of 437 and 58 days, respectively. The orbits have large eccentricities ofe = 0.45 ande = 0.54, respectively. All nine known extrasolar planet candidates witha = 0.2-2.5 AU have orbital eccentricities greater than 0.1, higher than that of Jupiter (e = 0.05). Eccentric orbits may result from gravitational perturbations imposed by other orbiting planets or stars, by passing stars in the dense star-forming cluster, or by the protoplanetary disk. Based on published studies and our near-IR adaptive optics images, HD 210277 appears to be a single star. However, HD 168443 exhibits a long-term velocity trend consistent with a close stellar companion, as yet undetected directly.
Footnotes
- *
Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology, and based on observations obtained at Lick Observatory, which is operated by the University of California.