TY - JOUR
T1 - A highly inclined orbit for the 110 day period m-dwarf companion KOI-368.01
AU - Zhou, George
AU - Huang, Chelsea X.
PY - 2013/10/20
Y1 - 2013/10/20
N2 - 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 . 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.
AB - 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 . 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.
KW - binaries: eclipsing
KW - stars: individual (KOI-368)
KW - stars: low-mass
KW - techniques: photometric
UR - http://www.scopus.com/inward/record.url?scp=84885363093&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/776/2/L35
DO - 10.1088/2041-8205/776/2/L35
M3 - Article
SN - 2041-8205
VL - 776
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L35
ER -