Site Map
Contacts
Follow us on Facebook Follow us on Twitter YouTube channel
Centro de Astrofísica da Universidade do Porto

Analysis of spin-orbit alignment in the WASP-32, WASP-38, and HAT-p-27/WASP-40 systems

D. Brown, A. Collier Cameron, R. F. Díaz, 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, G. Hébrard

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 (Teff = 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 (Teff = 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 (Teff = 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.

Notes
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.

The Astrophysical Journal
Volume 760, Page 139_1
December 2012

>> PDF>> ADS>> DOI

Institute of Astrophysics and Space Sciences

Institute of Astrophysics and Space Sciences (IA) is a new but long anticipated research infrastructure with a national dimension. It embodies a bold but feasible vision for the development of Astronomy, Astrophysics and Space Sciences in Portugal, taking full advantage and fully realizing the potential created by the national membership of the European Space Agency (ESA) and the European Southern Observatory (ESO). IA resulted from the merging the two most prominent research units in the field in Portugal: the Centre for Astrophysics of the University of Porto (CAUP) and the Center for Astronomy and Astrophysics of the University of Lisbon (CAAUL). It currently hosts more than two-thirds of all active researchers working in Space Sciences in Portugal, and is responsible for an even greater fraction of the national productivity in international ISI journals in the area of Space Sciences. This is the scientific area with the highest relative impact factor (1.65 times above the international average) and the field with the highest average number of citations per article for Portugal.

Proceed on CAUP's website|Go to IA website