KEPLER-63b: A GIANT PLANET IN A POLAR ORBIT AROUND A YOUNG SUN-LIKE STAR
We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, m [subscript Kp] = 11.6, T [subscript eff] = 5576 K, M [star] = 0.98 M [subscript ☉]). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies cau...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
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Other Authors: | |
Format: | Article |
Language: | en_US |
Published: |
IOP Publishing
2014
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Online Access: | http://hdl.handle.net/1721.1/88680 https://orcid.org/0000-0002-4265-047X |
Summary: | We present the discovery and characterization of a giant planet orbiting the young Sun-like star Kepler-63 (KOI-63, m [subscript Kp] = 11.6, T [subscript eff] = 5576 K, M [star] = 0.98 M [subscript ☉]). The planet transits every 9.43 days, with apparent depth variations and brightening anomalies caused by large starspots. The planet's radius is 6.1 ± 0.2 R [subscript ⊕], based on the transit light curve and the estimated stellar parameters. The planet's mass could not be measured with the existing radial-velocity data, due to the high level of stellar activity, but if we assume a circular orbit, then we can place a rough upper bound of 120 M [subscript ⊕] (3σ). The host star has a high obliquity (ψ = 104°), based on the Rossiter-McLaughlin effect and an analysis of starspot-crossing events. This result is valuable because almost all previous obliquity measurements are for stars with more massive planets and shorter-period orbits. In addition, the polar orbit of the planet combined with an analysis of spot-crossing events reveals a large and persistent polar starspot. Such spots have previously been inferred using Doppler tomography, and predicted in simulations of magnetic activity of young Sun-like stars. |
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