TY - JOUR
T1 - KELT-1b
T2 - A Strongly Irradiated, Highly Inflated, Short Period, 27 Jupiter-mass Companion Transiting a Mid-F Star
AU - Siverd, R.J.
AU - Beatty, T.G.
AU - Pepper, J,
AU - Eastman, J.D.
AU - Collins, K.
AU - Bieryla, A.
AU - Latham, D.W.
AU - Jensen, E.N.
AU - Crepp, J.R.
AU - Street, R.
AU - Buchhave, Lars C. Astrup
PY - 2012/12/10
Y1 - 2012/12/10
N2 - We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V = 10.7 primary is a mildly evolved mid-F star with T eff= 6516 ± 49 K, log g = 4.228 +0.014-0.021, and [Fe/H] = 0.052 ± 0.079, with an inferred mass M⊙* = 1.335 ± 0.063 M ⊙and radius R* = 1.471+0.045 -0.035 R. The companion is a low-mass brown dwarf or a super-massive planet with mass MP= 27.38 ± 0.93 M⊙Jup and radius RP= 1.116+0.038-0.029RJup. The companion is on a very short (∼29 hr) period circular orbit, with an ephemeris Tc(BJDTDB) = 2455909.29280 ± 0.00023 and P = 1.217501 ± 0.000018 days. KELT-1b receives a large amount of stellar insolation, resulting in an estimated equilibrium temperature assuming zero albedo and perfect redistribution of T eq= 2423+34 -27 K. Comparison with standard evolutionary models suggests that the radius of KELT-1b is likely to be significantly inflated. Adaptive optics imaging reveals a candidate stellar companion to KELT-1 with a separation of 588 ± 1 mas, which is consistent with an M dwarf if it is at the same distance as the primary. Rossiter-McLaughlin measurements during transit imply a projected spin-orbit alignment angle λ = 2 ± 16 deg, consistent with a zero obliquity for KELT-1. Finally, the vsin I* = 56 ± 2 km s-1 of the primary is consistent at ∼2σ with tidal synchronization. Given the extreme parameters of the KELT-1 system, we expect it to provide an important testbed for theories of the emplacement and evolution of short-period companions, as well as theories of tidal dissipation and irradiated brown dwarf atmospheres.
AB - We present the discovery of KELT-1b, the first transiting low-mass companion from the wide-field Kilodegree Extremely Little Telescope-North (KELT-North) transit survey. A joint analysis of the spectroscopic, radial velocity, and photometric data indicates that the V = 10.7 primary is a mildly evolved mid-F star with T eff= 6516 ± 49 K, log g = 4.228 +0.014-0.021, and [Fe/H] = 0.052 ± 0.079, with an inferred mass M⊙* = 1.335 ± 0.063 M ⊙and radius R* = 1.471+0.045 -0.035 R. The companion is a low-mass brown dwarf or a super-massive planet with mass MP= 27.38 ± 0.93 M⊙Jup and radius RP= 1.116+0.038-0.029RJup. The companion is on a very short (∼29 hr) period circular orbit, with an ephemeris Tc(BJDTDB) = 2455909.29280 ± 0.00023 and P = 1.217501 ± 0.000018 days. KELT-1b receives a large amount of stellar insolation, resulting in an estimated equilibrium temperature assuming zero albedo and perfect redistribution of T eq= 2423+34 -27 K. Comparison with standard evolutionary models suggests that the radius of KELT-1b is likely to be significantly inflated. Adaptive optics imaging reveals a candidate stellar companion to KELT-1 with a separation of 588 ± 1 mas, which is consistent with an M dwarf if it is at the same distance as the primary. Rossiter-McLaughlin measurements during transit imply a projected spin-orbit alignment angle λ = 2 ± 16 deg, consistent with a zero obliquity for KELT-1. Finally, the vsin I* = 56 ± 2 km s-1 of the primary is consistent at ∼2σ with tidal synchronization. Given the extreme parameters of the KELT-1 system, we expect it to provide an important testbed for theories of the emplacement and evolution of short-period companions, as well as theories of tidal dissipation and irradiated brown dwarf atmospheres.
U2 - 10.1088/0004-637X/761/2/123
DO - 10.1088/0004-637X/761/2/123
M3 - Journal article
SN - 0004-637X
VL - 761
SP - 123
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
ER -