We have measured the alignment between the orbit of HATS-3b (a recently discovered, slightly inflated Hot Jupiter) and the spin-axis of its host star. Data were obtained using the CYCLOPS2 optical-fiber bundle and its simultaneous calibration system feeding the UCLES spectrograph on the Anglo-Australian Telescope. The sky-projected spin-orbit angle of λ=3±25∘ was determined from spectroscopic measurements of Rossiter-McLaughlin effect. This is the first exoplanet discovered through the HATSouth transit survey to have its spin-orbit angle measured. Our results indicate that the orbital plane of HATS-3b is consistent with being aligned to the spin axis of its host star. The low obliquity of the HATS-3 system, which has a relatively hot mid F-type host star, agrees with the general trend observed for Hot Jupiter host stars with effective temperatures >6250K to have randomly distributed spin-orbit angles.
@article{arxiv.1407.7710,
title = {A Spin-Orbit Alignment for the Hot Jupiter HATS-3b},
author = {B. C. Addison and C. G. Tinney and D. J. Wright and D. Bayliss},
journal= {arXiv preprint arXiv:1407.7710},
year = {2015}
}
Comments
13 pages. Accepted for publication in the Astrophysical Journal