2012ApJ...760..139B

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 = 10°.5^ + 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 = 7°.5^ + 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 = 24°.2^ + 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.