KELT-12b: A P ∼ 5 day, Highly Inflated Hot Jupiter Transiting a Mildly Evolved Hot Star
- Department of Astronomy, The Ohio State University, 140 W. 18th Ave., Columbus, OH 43210 (United States)
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN 37235 (United States)
- Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States)
- Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States)
- Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
- Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
- Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States)
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States)
- Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA 19081 (United States)
- Società Astronomica Lunae, Castelnuovo Magra I-19030 (Italy)
- Dipartimento di Fisica “E. R. Caianiello,” Università di Salerno, Via Giovanni Paolo II 132, I-84084 Fisciano (Saudi Arabia) (Italy)
- Department of Physical Sciences, Kutztown University, Kutztown, PA 19530 (United States)
- Atalaia Group and Crow-Observatory, Portalegre (Portugal)
We announce the discovery of KELT-12b, a highly inflated Jupiter-mass planet transiting the mildly evolved, V = 10.64 host star TYC 2619-1057-1. We followed up the initial transit signal in the KELT-North survey data with precise ground-based photometry, high-resolution spectroscopy, precise radial velocity measurements, and high-resolution adaptive optics imaging. Our preferred best-fit model indicates that the host star has T{sub eff} = 6279 ± 51 K, logg{sub ⋆} = 3.89 ± 0.05, [Fe/H] = 0.19{sub −0.09}{sup +0.08}, M{sub ∗} = 1.59{sub −0.09}{sup +0.07} M{sub ⊙}, and R{sub ∗} = 2.37 ± 0.17 R{sub ⊙}. The planetary companion has M{sub P} = 0.95 ± 0.14 M{sub J}, R{sub P} = 1.78{sub −0.16}{sup +0.17} R{sub J}, logg{sub P} = 2.87{sub −0.10}{sup +0.09}, and density ρ{sub P} = 0.21{sub −0.05}{sup +0.07} g cm{sup −3}, making it one of the most inflated giant planets known. Furthermore, for future follow-up, we report a high-precision time of inferior conjunction in BJD{sub TDB} of 2,457,083.660459 ± 0.000894 and period of P=5.0316216±0.000032 days. Despite the relatively large separation of ∼0.07 au implied by its ∼5.03-day orbital period, KELT-12b receives significant flux of 2.38{sub −0.29}{sup +0.32}×10{sup 9} erg s{sup −1} cm{sup −2} from its host. We compare the radii and insolations of transiting gas giant planets around hot (T{sub eff}⩾6250 K) and cool stars, noting that the observed paucity of known transiting giants around hot stars with low insolation is likely due to selection effects. We underscore the significance of long-term ground-based monitoring of hot stars and space-based targeting of hot stars with the Transiting Exoplanet Survey Satellite to search for inflated gas giants in longer-period orbits.
- OSTI ID:
- 22863104
- Journal Information:
- The Astronomical Journal (Online), Vol. 153, Issue 4; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 1538-3881
- Country of Publication:
- United States
- Language:
- English
Similar Records
KELT-16b: A Highly Irradiated, Ultra-short Period Hot Jupiter Nearing Tidal Disruption
KELT-11b: A Highly Inflated Sub-Saturn Exoplanet Transiting the V = 8 Subgiant HD 93396