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Title: Spin-orbit alignment for 110 day period KOI368.01 from gravity darkening

We fit the Kepler photometric light curve of the KOI-368 system using an oblate, gravity-darkened stellar model in order to constrain its spin-orbit alignment. We find that the system is relatively well-aligned with a sky-projected spin-orbit alignment of λ = 10° ± 2°, a stellar obliquity of ψ = 3° ± 7°, and a true spin-orbit alignment of ψ = 11° ± 3°. Although our measurement differs significantly from zero, the low value for ψ is consistent with spin-orbit alignment. We also measure various transit parameters of the KOI-368 system: R {sub KOI-368} = 2.28 ± 0.02 R {sub ☉}, R{sub p} = 1.83 ± 0.02 R {sub jup}, and i = 89.°221 ± 0.°013. This work shows that our gravity-darkened model can constrain long-period, well-aligned planets and M-class stars orbiting fast-rotators, allowing for measurement of a new subcategory of transiting bodies.
Authors:
; ;  [1]
  1. Department of Physics, University of Idaho, 875 Perimeter Drive Stop 440903, Moscow, ID 83844-0903 (United States)
Publication Date:
OSTI Identifier:
22356941
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ALIGNMENT; COSMOLOGICAL MODELS; ECLIPSE; GRAVITATION; L-S COUPLING; ORBITS; PHOTOMETRY; PLANETS; SATELLITES; SPIN; STARS; VISIBLE RADIATION