The NASA-UC Eta-Earth Program. III. A Super-Earth Orbiting HD 97658 and a Neptune-mass Planet Orbiting Gl 785
Abstract
We report the discovery of planets orbiting two bright, nearby early K dwarf stars, HD 97658 and Gl 785. These planets were detected by Keplerian modeling of radial velocities measured with Keck-HIRES for the NASA-UC Eta-Earth Survey. HD 97658 b is a close-in super-Earth with minimum mass Msin i = 8.2 ± 1.2 M ⊕, orbital period P = 9.494 ± 0.005 days, and an orbit that is consistent with circular. Gl 785 b is a Neptune-mass planet with Msin i = 21.6 ± 2.0 M ⊕, P = 74.39 ± 0.12 days, and orbital eccentricity e = 0.30 ± 0.09. Photometric observations with the T12 0.8 m automatic photometric telescope at Fairborn Observatory show that HD 97658 is photometrically constant at the radial velocity period to 0.09 mmag, supporting the existence of the planet.
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. Keck time has been granted by both NASA and the University of California.- Publication:
-
The Astrophysical Journal
- Pub Date:
- March 2011
- DOI:
- 10.1088/0004-637X/730/1/10
- arXiv:
- arXiv:1011.0414
- Bibcode:
- 2011ApJ...730...10H
- Keywords:
-
- planetary systems;
- stars: individual: HD 97658 Gl 785;
- techniques: radial velocities;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Submitted to ApJ, 7 pages, 6 figures, 5 tables