Analysis of spin-orbit alignment in the WASP-32, WASP-38, and HAT-P-27/WASP-40 systems
Abstract
We present measurements of the spin-orbit alignment angle, λ, 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+90 - 100 K) is aligned, with an alignment angle of λ = 10fdg5 + 6.4 - 6.5 obtained through tomography, and that WASP-38 (T eff = 6180+40 - 60 K) is also aligned, with tomographic analysis yielding λ = 7fdg5 + 4.7 - 6.1. The latter result provides an order-of-magnitude improvement in the uncertainty in λ 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+160 - 170 K) to λ = 24fdg2 + 76.0 - 44.5, 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. Based on observations (under proposal 087.C-0649) made using the HARPS High Resolution Échelle Spectrograph mounted on the ESO 3.6 m at the ESO La Silla observatory.
Citation
Brown , D J A , Cameron , A C , Díaz , R F , Doyle , A P , Gillon , M , Lendl , M , Smalley , B , Triaud , A H M J , Anderson , D R , Enoch , B , Hellier , C , Maxted , P F L , Miller , G R M , Pollacco , D , Queloz , D , Boisse , I & Hébrard , G 2012 , ' Analysis of spin-orbit alignment in the WASP-32, WASP-38, and HAT-P-27/WASP-40 systems ' , Astrophysical Journal , vol. 760 , no. 2 , pp. 139 . https://doi.org/10.1088/0004-637X/760/2/139
Publication
Astrophysical Journal
Status
Peer reviewed
ISSN
0004-637XType
Journal article
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