TY - JOUR
T1 - The Rossiter-McLaughlin effect of the transiting exoplanet XO-4b
AU - Narita, Norio
AU - Hirano, Teruyuki
AU - Sanchis-Ojeda, Roberto
AU - Winn, Joshua N.
AU - Holman, Matthew J.
AU - Sato, Bun'ei
AU - Aoki, Wako
AU - Tamura, Motohide
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2010/12/25
Y1 - 2010/12/25
N2 - We report photometric and radial velocity observations of the XO-4 transiting planetary system, conducted with the FLWO 1.2 m telescope and the 8.2 m Subaru Telescope. Based on the new light curves, the refined transit ephemeris of XO-4b is P = 4.1250828± 0.0000040d and Tc [BJDTDB] = 2454485.93323± 0.00039.We measured the Rossiter-McLaughlin effect of XO-4b and estimated the sky-projected angle between the stellar spin axis and the planetary orbital axis to be λ = -46° 7+8° 1 -6° 1. This measurement of λ is less robust than in some other cases because the impact parameter of the transit is small, causing a strong degeneracy between λ and the projected stellar rotational velocity. Nevertheless, our finding of a spin-orbit misalignment suggests that the migration process for XO-4b involved few-body dynamics rather than interaction with a gaseous disk. In addition, our result conforms with the pattern reported by Winn et al. (2010, ApJ, 718, L145) that high obliquities are preferentially found for stars with effective temperatures hotter than 6250 K
AB - We report photometric and radial velocity observations of the XO-4 transiting planetary system, conducted with the FLWO 1.2 m telescope and the 8.2 m Subaru Telescope. Based on the new light curves, the refined transit ephemeris of XO-4b is P = 4.1250828± 0.0000040d and Tc [BJDTDB] = 2454485.93323± 0.00039.We measured the Rossiter-McLaughlin effect of XO-4b and estimated the sky-projected angle between the stellar spin axis and the planetary orbital axis to be λ = -46° 7+8° 1 -6° 1. This measurement of λ is less robust than in some other cases because the impact parameter of the transit is small, causing a strong degeneracy between λ and the projected stellar rotational velocity. Nevertheless, our finding of a spin-orbit misalignment suggests that the migration process for XO-4b involved few-body dynamics rather than interaction with a gaseous disk. In addition, our result conforms with the pattern reported by Winn et al. (2010, ApJ, 718, L145) that high obliquities are preferentially found for stars with effective temperatures hotter than 6250 K
KW - Stars:planetary systems:individual (XO-4)
KW - Stars:rotation
KW - Techniques:photometric
KW - Techniques:radial velocities
KW - Techniques:spectroscopic
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U2 - 10.1093/pasj/62.6.L61
DO - 10.1093/pasj/62.6.L61
M3 - Article
AN - SCOPUS:79251507319
VL - 62
SP - L61-L65
JO - Publication of the Astronomical Society of Japan
JF - Publication of the Astronomical Society of Japan
SN - 0004-6264
IS - 6
ER -