Jonathan Labadie-Bartz, University of Delaware
Joseph E. Rodriguez, Harvard-Smithsonian Center for Astrophysics
Keivan G. Stassun, Vanderbilt University
David R. Ciardi, California Institute of Technology
Kaloyan Penev, The University of Texas at Dallas
Marshall C. Johnson, The Ohio State University
B. Scott Gaudi, The Ohio State University
Knicole D. Colón, NASA Goddard Space Flight Center
Allyson Bieryla, Harvard-Smithsonian Center for Astrophysics
David W. Latham, Harvard-Smithsonian Center for Astrophysics
Joshua Pepper, Lehigh University
Karen A. Collins, Harvard-Smithsonian Center for Astrophysics
Phil Evans, El Sauce Observatory
Howard Relles, Harvard-Smithsonian Center for Astrophysics
Robert J. Siverd, Las Cumbres Observatory Global Telescope Network, Inc
Joao Bento, Australian National University, Mount Stromlo Observatory
Xinyu Yao, Lehigh University
Chris Stockdale, Hazelwood Observatory
Thiam Guan Tan, Perth Exoplanet Survey Telescope
George Zhou, Harvard-Smithsonian Center for Astrophysics
Jason D. Eastman, Harvard-Smithsonian Center for Astrophysics
Michael D. Albrow, University of Canterbury
Daniel Bayliss, Australian National University, Mount Stromlo Observatory
Thomas G. Beatty, Pennsylvania State University
Perry Berlind, Harvard-Smithsonian Center for Astrophysics
Valerio Bozza, Università degli Studi di Salerno
Michael L. Calkins, Harvard-Smithsonian Center for Astrophysics
David H. Cohen, Swarthmore College
Ivan A. Curtis, Ivan Curtis Private Observatory
Gilbert A. Esquerdo, Harvard-Smithsonian Center for Astrophysics
Dax Feliz, Vanderbilt University
Benjamin J. Fulton, Division of Geological and Planetary Sciences
Joao Gregorio, Atalaia Group and CROW Observatory

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We present the discovery of KELT-22Ab, a hot Jupiter from the KELT-South survey. KELT-22Ab transits the moderately bright (V ∼ 11.1) Sun-like G2V star TYC 7518-468-1. The planet has an orbital period of days, a radius of , and a relatively large mass of . The star has , , K, (cgs), and [m/H] = ; thus other than its slightly super-solar metallicity, it 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 rapidly for its estimated age, and shows evidence of chromospheric activity. Imaging reveals a slightly fainter companion to KELT-22A that is likely bound, with a projected separation of 6″ (∼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 semimajor axis of ), 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 semimajor axis is decreasing rapidly, and KELT-22Ab is predicted to spiral into the star within the next Gyr.

Publication Source (Journal or Book title)

Astrophysical Journal, Supplement Series