KELT-22Ab: A Massive Hot Jupiter Transiting a Near Solar Twin
Creators: name: Labadie-Bartz, Jonathan
name: Rodriguez, Joseph E.
name: Stassun, Keivan G.
name: Ciardi, David R.
name: Johnson, Marshall C.
name: Gaudi, B. Scott
name: Penev, Kaloyan M.
name: Bieryla, Allyson
name: Latham, David W.
name: Pepper, Joshua
name: Collins, Karen A.
name: Evans, Phil
name: Relles, Howard M.
name: Siverd, Robert J.
name: Bento, Joao
name: Yao, Xinyu
name: Stockdale, Chris
name: Tan, Thiam-Guan
name: Zhou, George
name: Colon, Knicole D.
name: Eastman, Jason D.
name: Albrow, Michael D.
name: Malpas, Amber
name: Bayliss, Daniel
name: Beatty, Thomas G.
name: Bozza, Valerio
name: Cohen, David H.
name: Curtis, Ivan A.
name: DePoy, Darren L.
name: Feliz, Dax
name: Fulton, Benjamin J.
name: Gregorio, Joao
name: James, David
name: Jang-Condell, Hannah
name: Jensen, Eric L.
name: Johnson, John A.
name: Johnson, Samson A.
name: Joner, Michael D.
name: Kielkopf, John
name: Kuhn, Rudolf B.
name: Lund, Michael B.
name: Manner, Mark
name: Marshall, Jennifer L.
name: McCrady, Nate
name: McLeod, Kim K.
name: Oberst, Thomas E.
name: Penny, Matthew T.
name: Pogge, Rick
name: Reed, Phillip A.
name: Sliski, David H.
name: Stephens, Denise C.
name: Stevens, Daniel J.
name: Trueblood, Mark
name: Trueblood, Patricia
name: Villanueva, Steven
name: Wittenmyer, Robert A.
name: Wright, Jason T.
name: Zambelli, Roberto
name: Berlind, Perry
name: Calkins, Michael L.
name: Esquerdo, Gilbert A.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present the discovery of KELT-22Ab, a hot Jupiter from the KELT-South survey. KELT-22Ab transits the moderately bright ($V\sim 11.1$) Sun-like G2V star TYC 7518-468-1. The planet has an orbital period of $P = 1.3866529 \pm 0.0000027 $ days, a radius of $R_{P} = 1.285_{-0.071}^{+0.12}~R_{J}$, and a relatively large mass of $M_{P} = 3.47_{-0.14}^{+0.15}~ M_{J}$. The star has $R_{\star} = 1.099_{-0.046}^{+0.079}~ R_{\odot}$, $M_{\star} = 1.092_{-0.041}^{+0.045}~ M_{\odot}$, ${T_{\rm eff}\,} = 5767_{-49}^{+50}~$ K, ${\log{g_\star}} = 4.393_{-0.060}^{+0.039}~$ (cgs), and [m/H] = $+0.259_{-0.083}^{+0.085}~$, and thus, other than its slightly super-solar metallicity, appears to be a near solar twin. Surprisingly, KELT-22A exhibits kinematics and a Galactic orbit that are somewhat atypical for thin disk stars. Nevertheless, the star is rotating quite rapidly for its estimated age, shows evidence of chromospheric activity, and is somewhat metal rich. Imaging reveals a slightly fainter companion to KELT-22A that is likely bound, with a projected separation of 6\arcsec ($\sim$1400 AU). In addition to the orbital motion caused by the transiting planet, we detect a possible linear trend in the radial velocity of KELT-22A suggesting the presence of another relatively nearby body that is perhaps non-stellar. KELT-22Ab is highly irradiated (as a consequence of the small semi-major axis of $a/R_{\star} = 4.97$), and is mildly inflated. At such small separations, tidal forces become significant. The configuration of this system is optimal for measuring the rate of tidal dissipation within the host star. Our models predict that, due to tidal forces, the semi-major axis of KELT-22Ab is decreasing rapidly, and is thus predicted to spiral into the star within the next Gyr.
description: 14 pages, 13 figures, 5 tables