@article{5844419cf0a542e5b09de0b8ae109d8e,
title = "KELT-12b: A P ∼ 5 day, Highly Inflated Hot Jupiter Transiting a Mildly Evolved Hot Star",
abstract = "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 = 6279 ±51 K, = 3.89 ±0.05, [Fe/H] = 0.19+0.08 -0.09, = M∗ = 1.59+0.07 0.09M, and R ∗= 2.37 ±0.17 . The planetary companion has Mp= 0.95 ±0.14 MJ, RP = 1.78+0.17-0.16 RJ, log gP = 2.87+0.9 -0.09 and density pp 0.210.07 0.05= g cm-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 BJDTDB of 2,457,083.660459 ±0.000894 and period of P = 5.0316216 ± 0.000032days. 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+0.32 -0.29 × 109 erg s-1 cm-2 from its host. We compare the radii and insolations of transiting gas giant planets around hot (Teff 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.",
author = "Stevens, {Daniel J.} and Collins, {Karen A.} and Gaudi, {B. Scott} and Beatty, {Thomas G.} and Siverd, {Robert J.} and Allyson Bieryla and Fulton, {Benjamin J.} and Crepp, {Justin R.} and Gonzales, {Erica J.} and Coker, {Carl T.} and Kaloyan Penev and Stassun, {Keivan G.} and Jensen, {Eric L.N.} and Howard, {Andrew W.} and Latham, {David W.} and Rodriguez, {Joseph E.} and Roberto Zambelli and Valerio Bozza and Reed, {Phillip A.} and Joao Gregorio and Buchhave, {Lars A.} and Penny, {Matthew T.} and Joshua Pepper and Perry Berlind and Novati, {Sebastiano Calchi} and Calkins, {Michael L.} and Giuseppe D'Ago and Eastman, {Jason D.} and D. Bayliss and Col{\'o}n, {Knicole D.} and Curtis, {Ivan A.} and DePoy, {D. L.} and Esquerdo, {Gilbert A.} and Andrew Gould and Joner, {Michael D.} and Kielkopf, {John F.} and Jonathan Labadie-Bartz and Lund, {Michael B.} and Mark Manner and Marshall, {Jennifer L.} and McLeod, {Kim K.} and Oberst, {Thomas E.} and Pogge, {Richard W.} and Gaetano Scarpetta and Stephens, {Denise C.} and Christopher Stockdale and Tan, {T. G.} and Mark Trueblood and Patricia Trueblood",
note = "Funding Information: DSSI data presented herein were obtained at the WIYN Observatory from telescope time allocated to NN-EXPLORE through the scientific partnership of the National Aeronautics and Space Administration, the National Science Foundation, and the National Optical Astronomy Observatory. This work was supported by a NASA WIYN PI Data Award, administered by the NASA Exoplanet Science Institute. We gratefully acknowledge the help of the DSSI team in observing KELT-12 and reducing the DSSI data. Publisher Copyright: {\textcopyright} 2017. The American Astronomical Society. All rights reserved.",
year = "2017",
month = apr,
doi = "10.3847/1538-3881/aa5ffb",
language = "English (US)",
volume = "153",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "4",
}