A HIGHLY INCLINED ORBIT FOR THE 110 DAY PERIOD M-DWARF COMPANION KOI-368.01

Journal Article · Sun Oct 20 04:00:00 EDT 2013 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/776/2/L35· OSTI ID:22215429

Zhou, George ^[1]

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1. Research School of Astronomy and Astrophysics, Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia)

We report the detection of asymmetry in the transit light curves of the 110 day period companion to KOI-368, a rapidly rotating A-dwarf. The significant distortion in the transit light curve is attributed to spin-orbit misalignment between the transiting companion and the gravity darkened host star. Our analysis was based on 11 long cadence and 2 short cadence transits of KOI-368.01 from the Kepler mission, as well as stellar parameters determined from our follow-up spectroscopic observation. We measured the true obliquity between the orbit normal and the stellar rotation axis to be 69{sub -10}{sup +9o}. We also find a secondary eclipse event with depth 29 ± 3 ppm at phase 0.59, from which the temperature of the companion is constrained to 3060 ± 50 K, indicating that KOI-368.01 is a late M-dwarf. The eccentricity is also calculated from the eclipse to be 0.1429 ± 0.0007. The long period, high obliquity, and low eccentricity of KOI-368.01 allow us to limit a number of proposed theories for the misalignment of binary systems.

• OSTI ID: 22215429
• Journal Information: Astrophysical Journal Letters, Journal Name: Astrophysical Journal Letters Journal Issue: 2 Vol. 776; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ASYMMETRY
DEPTH
DETECTION
ECLIPSE
GRAVITATION
ORBITS
ROTATION
STARS
VISIBLE RADIATION