Substellar Companions to Evolved Intermediate-Mass Stars: HD 145457 and HD 180314
Abstract
We report on the detection of two substellar companions orbiting around evolved intermediate-mass stars by precise Doppler measurements at Subaru Telescope and Okayama Astrophysical Observatory. HD 145457 is a K0 giant with a mass of 1.9Modot, and has a planet of minimum mass, m2 sin i = 2.9MJ, orbiting with a period of P = 176d and eccentricity of e = 0.11. HD 180314 is also a K0 giant with 2.6Modot, and hosts a substellar companion of m2 sin i = 22MJ, which falls in the brown-dwarf mass regime, in an orbit with P = 396d and e = 0.26. HD 145457 b is one of the innermost planets and HD 180314 b is the seventh candidate of a brown-dwarf-mass companion found around evolved intermediate-mass stars.
- Publication:
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Publications of the Astronomical Society of Japan
- Pub Date:
- August 2010
- DOI:
- arXiv:
- arXiv:1005.2860
- Bibcode:
- 2010PASJ...62.1063S
- Keywords:
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- stars: individual (HD 145457);
- stars: individual (HD 180314);
- stars: planetary systems;
- techniques: radial velocities;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 16 pages, 4 figures, accepted for publication in PASJ