Spin-orbit measurements and refined parameters for the exoplanet systems WASP-22 and WASP-26

D. R. Anderson; A. Collier Cameron; M. Gillon; C. Hellier; E. Jehin; M. Lendl; D. Queloz; B. Smalley; A. H. M. J. Triaud; M. Vanhuysse

doi:10.1051/0004-6361/201117597

arXiv · 1106.6092

Spin-orbit measurements and refined parameters for the exoplanet systems WASP-22 and WASP-26

D. R. Anderson·A. Collier Cameron·M. Gillon·C. Hellier·E. Jehin·M. Lendl·D. Queloz·B. Smalley·A. H. M. J. Triaud·M. Vanhuysse

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Abstract

We report on spectroscopic and photometric observations through transits of the exoplanets WASP-22b and WASP-26b, intended to determine the systems' spin-orbit angles. We combine these data with existing data to refine the system parameters. We measure a sky-projected spin-orbit angle of 22 +/- 16 deg for WASP-22b, showing the planet's orbit to be prograde and, perhaps, slightly misaligned. We do not detect the Rossiter-McLaughlin effect of WASP-26b due to its low amplitude and observation noise. We place 3-sigma upper limits on orbital eccentricity of 0.063 for WASP-22b and 0.050 for WASP-26b. After refining the drift in the systemic velocity of WASP-22 found by Maxted et al. (2010, AJ, 140, 2007) we find the third body in the system to have a minimum-mass of 5.3 +/- 0.3 Mjup (a3/5 AU)^2, where a3 is the orbital distance of the third body.

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D. R. Anderson, A. Collier Cameron, M. Gillon, C. Hellier, E. Jehin, M. Lendl, D. Queloz, B. Smalley, A. H. M. J. Triaud, M. Vanhuysse. 2011-06-30. Spin-orbit measurements and refined parameters for the exoplanet systems WASP-22 and WASP-26. https://doi.org/10.1051/0004-6361/201117597

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