ANALYSIS OF SPIN-ORBIT ALIGNMENT IN THE WASP-32, WASP-38, AND HAT-P-27/WASP-40 SYSTEMS

D. J. A. Brown , A. Collier Cameron , R. F. Diaz , A. P. Doyle , M. Gillon , M. Lendl , B. Smalley , A. H. M. J. Triaud , D. R. Anderson , B. Enoch , C. Hellier , P. F. L. Maxted , G. R. M. Miller , D. Pollacco , D. Queloz , I. Boisse (1) , G. Hebrard

1 LAM - Laboratoire d'Astrophysique de Marseille

We present measurements of the spin-orbit alignment angle,., for the hot Jupiter systems WASP-32, WASP-38, and HAT-P-27/WASP-40, based on data obtained using the HARPS spectrograph. We analyze the Rossiter-McLaughlin effect for all three systems and also carry out Doppler tomography for WASP-32 and WASP-38. We find that WASP-32 (T-eff = 6140(-100)(+90) K) is aligned, with an alignment angle of lambda = 10 degrees.5(-6.5)(+6.4) obtained through tomography, and that WASP-38 (T-eff = 6180(-60)(+40) K) is also aligned, with tomographic analysis yielding lambda = 7 degrees.5(-6.1)(+4.7). The latter result provides an order-of-magnitude improvement in the uncertainty in lambda compared to the previous analysis of Simpson et al. We are only able to loosely constrain the angle for HAT-P-27/WASP-40 (T-eff = 5190(-170)(+160) K) to lambda = 24 degrees.2(-44.5)(+76.0), owing to the poor signal-to-noise ratio of our data. We consider this result a non-detection under a slightly updated version of the alignment test of Brown et al. We place our results in the context of the full sample of spin-orbit alignment measurements, finding that they provide further support for previously established trends.

Domaines: Astrophysique [astro-ph]

D. J. A. Brown, A. Collier Cameron, R. F. Diaz, A. P. Doyle, M. Gillon, et al.. ANALYSIS OF SPIN-ORBIT ALIGNMENT IN THE WASP-32, WASP-38, AND HAT-P-27/WASP-40 SYSTEMS. The Astrophysical Journal, 2012, 760 (2), ⟨10.1088/0004-637X/760/2/139⟩. ⟨hal-01434442⟩