Characterization the Cool KOIs. II. The M Dwarf KOI-254 and its Hot Jupiter
Abstract
We report the confirmation and characterization of a transiting gas giant planet orbiting the M dwarf KOI-254 every 2.455239 days, which was originally discovered by the Kepler mission. We use radial velocity measurements, adaptive optics imaging, and near-infrared spectroscopy to confirm the planetary nature of the transit events. KOI-254 b is the first hot Jupiter discovered around an M-type dwarf star. We also present a new model-independent method of using broadband photometry to estimate the mass and metallicity of an M dwarf without relying on a direct distance measurement. Included in this methodology is a new photometric metallicity calibration based on J – K colors. We use this technique to measure the physical properties of KOI-254 and its planet. We measure a planet mass of M_P = 0.505 M_(Jup), radius R_P = 0.96 R_(Jup), and semimajor axis a = 0.030 AU, based on our measured stellar mass M_* = 0.59 M_☉ and radius R_* = 0.55 R_☉. We also find that the host star is metal-rich, which is consistent with the sample of M-type stars known to harbor giant planets.
Additional Information
© 2012 American Astronomical Society. Received 2011 December 22; accepted 2012 February 29; published 2012 April 4. 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 Caltech, the University of California and NASA. We gratefully acknowledge the efforts and dedication of the Keck Observatory staff, especially Grant Hill, Scott Dahm, and Hien Tran for their support of HIRES and Greg Wirth for support of remote observing. A.W. H. gratefully acknowledges support from a Townes Post-doctoral Fellowship at the U. C. Berkeley Space Sciences Laboratory. T. S. B. and K. R. C. acknowledge support provided by NASA through Hubble Fellowship grants HST-HF-51252.01 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contracts NAS 5-26555 and NAS 5-26555, respectively. We made use of the SIMBAD database operated at CDS, Strasbourg, France, and NASA's Astrophysics Data System Bibliographic Services. Finally, we extend special thanks to those of Hawaiian 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 - Johnson2012p18125Astron_J.pdf
Submitted - 1112.0017.pdf
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Additional details
- Eprint ID
- 31482
- Resolver ID
- CaltechAUTHORS:20120515-153434137
- University of California, Berkeley
- HST-HF-51235.01
- NASA Hubble Fellowship
- NAS 5-26555
- NASA
- Created
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2012-05-16Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field