KELT-8b: A HIGHLY INFLATED TRANSITING HOT JUPITER AND A NEW TECHNIQUE FOR EXTRACTING HIGH-PRECISION RADIAL VELOCITIES FROM NOISY SPECTRA

2015/05/31 by Benjamin J. Fulton, Karen A. Collins, B. Scott Gaudi +34
Physics and Astronomy · #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Brown dwarf #Effective temperature #Ephemeris #Exoplanet #Gamma-ray bursts and supernovae #Gas giant #Hot Jupiter #Jupiter (rocket family) #Light curve #Physics #Planet #RADIUS #Radial velocity #Satellite #Space exploration #Spectral line #Stars #Stellar, planetary, and galactic studies #Surface gravity #astro-ph.EP

paper · pdf · doi:10.1088/0004-637x/810/1/30

Submitted to ApJ, feedback is welcome

openalex publication_date 2015/08/27 · arxiv created 2015/09/26 · arxiv updated 2015/09/29 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/06

Abstract

We announce the discovery of a highly inflated transiting hot Jupiter by the KELT-North survey. A global analysis including constraints from isochrones indicates that the V = 10.8 host star (HD 343246) is a mildly evolved, G dwarf with K, , , an inferred mass , and radius . The planetary companion has a mass M J , radius R J , surface gravity , and density g cm −3 . The planet is on a roughly circular orbit with semimajor axis AU and eccentricity . The best-fit linear ephemeris is and days. This planet is one of the most inflated of all known transiting exoplanets, making it one of the few members of a class of extremely low density, highly irradiated gas giants. The low stellar and large implied radius are supported by stellar density constraints from follow-up light curves, as well as an evolutionary and space motion analysis. We also develop a new technique to extract high-precision radial velocities from noisy spectra that reduces the observing time needed to confirm transiting planet candidates. This planet boasts deep transits of a bright star, a large inferred atmospheric scale height, and a high equilibrium temperature of K, assuming zero albedo and perfect heat redistribution, making it one of the best targets for future atmospheric characterization studies.

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