TY - JOUR
T1 - KELT-20b
T2 - A Giant Planet with a Period of P ∼ 3.5 days Transiting the v ∼ 7.6 Early A Star HD 185603
AU - Lund, Michael B.
AU - Rodriguez, Joseph E.
AU - Zhou, George
AU - Gaudi, B. Scott
AU - Stassun, Keivan G.
AU - Johnson, Marshall C.
AU - Bieryla, Allyson
AU - Oelkers, Ryan J.
AU - Stevens, Daniel J.
AU - Collins, Karen A.
AU - Penev, Kaloyan
AU - Quinn, Samuel N.
AU - Latham, David W.
AU - Villanueva, Steven
AU - Eastman, Jason D.
AU - Kielkopf, John F.
AU - Oberst, Thomas E.
AU - Jensen, Eric L.N.
AU - Cohen, David H.
AU - Joner, Michael D.
AU - Stephens, Denise C.
AU - Relles, Howard
AU - Corfini, Giorgio
AU - Gregorio, Joao
AU - Zambelli, Roberto
AU - Esquerdo, Gilbert A.
AU - Calkins, Michael L.
AU - Berlind, Perry
AU - Ciardi, David R.
AU - Dressing, Courtney
AU - Patel, Rahul
AU - Gagnon, Patrick
AU - Gonzales, Erica
AU - Beatty, Thomas G.
AU - Siverd, Robert J.
AU - Labadie-Bartz, Jonathan
AU - Kuhn, Rudolf B.
AU - Colón, Knicole D.
AU - James, David
AU - Pepper, Joshua
AU - Fulton, Benjamin J.
AU - McLeod, Kim K.
AU - Stockdale, Christopher
AU - Calchi Novati, Sebastiano
AU - DePoy, D. L.
AU - Gould, Andrew
AU - Marshall, Jennifer L.
AU - Trueblood, Mark
AU - Trueblood, Patricia
AU - Johnson, John A.
AU - Wright, Jason
AU - McCrady, Nate
AU - Wittenmyer, Robert A.
AU - Johnson, Samson A.
AU - Sergi, Anthony
AU - Wilson, Maurice
AU - Sliski, David H.
PY - 2017/11
Y1 - 2017/11
N2 - We report the discovery of KELT-20b, a hot Jupiter transiting a V ∼7.6 early A star, HD 185603, with an orbital period of P ≃3.47 days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we infer that KELT-20 is a rapidly rotating (v sin I∗ ≃ 120 km s-1 ) A2V star with an effective temperature of Teff=8730 -260 +250 K, mass of M∗+1.76-0.20 +0.14MO, radius of R∗= 1.561-0.064+0.058RO,surface gravity of log g ∗=4.292-0.020+0.017, and age of ≳600 Myr. The planetary companion has a radius of Rp=1.735 -0.075 +0.070Rj, a semimajor axis of a =0.0542-0.0021+0.0014 au, and a linear ephemeris of BJDTDB=2457503.120049 ± 0.000190+E(3.4741070± 0.0000019). We place a 3s upper limit of ∼ 3.5 MJ on the mass of the planet. Doppler tomographic measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star (l = 3 °.4± 2 °.1). The inclination of the star is constrained to 24°.4 > I ∗ > 155 °.6, implying a three-dimensional spin-orbit alignment of 1°.3 > ψ > 69°.8. KELT-20b receives an insolation flux of∼8× 109 erg s-1cm-2, implying an equilibrium temperature of of ∼ 2250 K, assuming zero albedo and complete heat redistribution. Due to the high stellar Teff, KELT-20b also receives an ultraviolet (wavelength d ≤ 91.2 nm) insolation flux of ∼9.1×104erg s-1 cm-2, possibly indicating significant atmospheric ablation. Together with WASP-33, Kepler-13 A, HAT-P-57, KELT-17, and KELT-9, KELT-20 is the sixth A star host of a transiting giant planet, and the thirdbrightest host (in V) of a transiting planet.
AB - We report the discovery of KELT-20b, a hot Jupiter transiting a V ∼7.6 early A star, HD 185603, with an orbital period of P ≃3.47 days. Archival and follow-up photometry, Gaia parallax, radial velocities, Doppler tomography, and AO imaging were used to confirm the planetary nature of KELT-20b and characterize the system. From global modeling we infer that KELT-20 is a rapidly rotating (v sin I∗ ≃ 120 km s-1 ) A2V star with an effective temperature of Teff=8730 -260 +250 K, mass of M∗+1.76-0.20 +0.14MO, radius of R∗= 1.561-0.064+0.058RO,surface gravity of log g ∗=4.292-0.020+0.017, and age of ≳600 Myr. The planetary companion has a radius of Rp=1.735 -0.075 +0.070Rj, a semimajor axis of a =0.0542-0.0021+0.0014 au, and a linear ephemeris of BJDTDB=2457503.120049 ± 0.000190+E(3.4741070± 0.0000019). We place a 3s upper limit of ∼ 3.5 MJ on the mass of the planet. Doppler tomographic measurements indicate that the planetary orbit normal is well aligned with the projected spin axis of the star (l = 3 °.4± 2 °.1). The inclination of the star is constrained to 24°.4 > I ∗ > 155 °.6, implying a three-dimensional spin-orbit alignment of 1°.3 > ψ > 69°.8. KELT-20b receives an insolation flux of∼8× 109 erg s-1cm-2, implying an equilibrium temperature of of ∼ 2250 K, assuming zero albedo and complete heat redistribution. Due to the high stellar Teff, KELT-20b also receives an ultraviolet (wavelength d ≤ 91.2 nm) insolation flux of ∼9.1×104erg s-1 cm-2, possibly indicating significant atmospheric ablation. Together with WASP-33, Kepler-13 A, HAT-P-57, KELT-17, and KELT-9, KELT-20 is the sixth A star host of a transiting giant planet, and the thirdbrightest host (in V) of a transiting planet.
KW - methods: observational
KW - planets and satellites: detection
KW - planets and satellites: gaseous planets
KW - stars: individual (HD 185603)
KW - techniques: photometric
KW - techniques: radial velocities
UR - http://www.scopus.com/inward/record.url?scp=85034582287&partnerID=8YFLogxK
U2 - 10.3847/1538-3881/aa8f95
DO - 10.3847/1538-3881/aa8f95
M3 - Article
AN - SCOPUS:85034582287
SN - 0004-6256
VL - 154
JO - Astronomical Journal
JF - Astronomical Journal
IS - 5
M1 - 194
ER -