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 M sin 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 M sin 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.
Additional Information
© 2011 American Astrophysical Society. Received 2010 November 2; accepted 2010 December 30; published 2011 February 24. 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. We thank the many observers who contributed to the measurements reported here. We gratefully acknowledge the efforts and dedication of the Keck Observatory staff, especially Scott Dahm, Hien Tran, and Grant Hill for support of HIRES and Greg Wirth for support of remote observing. We are grateful to the time assignment committees of the University of California, NASA, and NOAO for their generous allocations of observing time. Without their long-term commitment to RV monitoring, these long-period planets would likely remain unknown. We acknowledge R. Paul Butler and S. S. Vogt for many years of contributing to the data presented here. G.W.M. acknowledges NASA grant NNX06AH52G. G.W.H. acknowledges support from NASA, NSF, Tennessee State University, and the State of Tennessee through its Centers of Excellence program. This work made use of the SIMBAD database (operated at CDS, Strasbourg, France), NASA's Astrophysics Data System Bibliographic Services, and the NASA Star and Exoplanet Database (NStED). Finally, the authors wish to extend special thanks to those of Hawai'ian ancestry on whose sacred mountain of Mauna Kea we are privileged to be guests. Without their generous hospitality, the Keck observations presented herein would not have been possible.Attached Files
Published - Howard2011p13382Astrophys_J.pdf
Files
| Name | Size | Download all |
|---|---|---|
|
md5:128b0e4a76d028ed025641e30cb69f15
|
572.6 kB | Preview Download |
Additional details
- Eprint ID
- 23326
- Resolver ID
- CaltechAUTHORS:20110414-085412339
- NASA
- NNX06AH52G
- NSF
- Tennessee State University
- State of Tennessee
- Created
-
2011-04-15Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field