KELT-16b: A Highly Irradiated, Ultra-short Period Hot Jupiter Nearing Tidal Disruption

March 2017 • 2017AJ....153...97O

Authors • Oberst, Thomas E. • Rodriguez, Joseph E. • Colón, Knicole D. • Angerhausen, Daniel • Bieryla, Allyson • Ngo, Henry • Stevens, Daniel J. • Stassun, Keivan G. • Gaudi, B. Scott • Pepper, Joshua • Penev, Kaloyan • Mawet, Dimitri • Latham, David W. • Heintz, Tyler M. • Osei, Baffour W. • Collins, Karen A. • Kielkopf, John F. • Visgaitis, Tiffany • Reed, Phillip A. • Escamilla, Alejandra • Yazdi, Sormeh • McLeod, Kim K. • Lunsford, Leanne T. • Spencer, Michelle • Joner, Michael D. • Gregorio, Joao • Gaillard, Clement • Matt, Kyle • Dumont, Mary Thea • Stephens, Denise C. • Cohen, David H. • Jensen, Eric L. N. • Calchi Novati, Sebastiano • Bozza, Valerio • Labadie-Bartz, Jonathan • Siverd, Robert J. • Lund, Michael B. • Beatty, Thomas G. • Eastman, Jason D. • Penny, Matthew T. • Manner, Mark • Zambelli, Roberto • Fulton, Benjamin J. • Stockdale, Christopher • DePoy, D. L. • Marshall, Jennifer L. • Pogge, Richard W. • Gould, Andrew • Trueblood, Mark • Trueblood, Patricia

Abstract • We announce the discovery of KELT-16b, a highly irradiated, ultra-short period hot Jupiter transiting the relatively bright (V = 11.7) star TYC 2688-1839-1/KELT-16. A global analysis of the system shows KELT-16 to be an F7V star with {T}_{eff}=6236+/- 54 K, {log}{g}_\star ={4.253}_-0.036^+0.031, [{Fe}/{{H}}]=-{0.002}_-0.085^+0.086, {M}_\star ={1.211}_-0.046^+0.043 {M}_⊙ , and {R}_\star ={1.360}_-0.053^+0.064{R}_⊙ . The planet is a relatively high-mass inflated gas giant with {M}_{{P}}={2.75}_-0.15^+0.16{M}_{{J}}, {R}_{{P}}={1.415}_-0.067^+0.084{R}_{{J}}, density {ρ }_{{P}}=1.20+/- 0.18 g cm^-3, surface gravity {log} {g}_{{P}}={3.530}_-0.049^+0.042, and {T}_{eq}={2453}_-47⁺⁵⁵ K. The best-fitting linear ephemeris is {T}_{{C}}=2457247.24791+/- 0.00019 {{BJD}}_{TDB} and P=0.9689951+/- 0.0000024 day. KELT-16b joins WASP-18b, -19b, -43b, -103b, and HATS-18b as the only giant transiting planets with P < 1 day. Its ultra-short period and high irradiation make it a benchmark target for atmospheric studies by the Hubble Space Telescope, Spitzer, and eventually the James Webb Space Telescope. For example, as a hotter, higher-mass analog of WASP-43b, KELT-16b may feature an atmospheric temperature-pressure inversion and day-to-night temperature swing extreme enough for TiO to rain out at the terminator. KELT-16b could also join WASP-43b in extending tests of the observed mass-metallicity relation of the solar system gas giants to higher masses. KELT-16b currently orbits at a mere ∼1.7 Roche radii from its host star, and could be tidally disrupted in as little as a few ×10⁵ years (for a stellar tidal quality factor of {Q}_* ^\prime ={10}⁵). Finally, the likely existence of a widely separated bound stellar companion in the KELT-16 system makes it possible that Kozai-Lidov (KL) oscillations played a role in driving KELT-16b inward to its current precarious orbit.

Links

• PREPRINT http://arxiv.org/abs/1608.00618
• ELECTR https://iopscience.iop.org/article/10.3847/1538-3881/153/3/97
• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2017AJ....153...97O
• PDF https://iopscience.iop.org/article/10.3847/1538-3881/153/3/97/pdf
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2017AJ....153...97O
• DATA https://irsa.ipac.caltech.edu/bibdata/2017/O/2017AJ....153...97O.html