HATS-5b: A transiting hot saturn from the HATsouth survey

Abstract

We report the discovery of HATS-5b, a transiting hot Saturn orbiting a G-type star, by the HATSouth survey. HATS-5b has a mass of Mp 0.24 MJ, radius of Rp 0.91 R J, and transits its host star with a period of P 4.7634 days. The radius of HATS-5b is consistent with both theoretical and empirical models. The host star has a V-band magnitude of 12.6, mass of 0.94 M ⊙, and radius of 0.87 R. The relatively high scale height of HATS-5b and the bright, photometrically quiet host star make this planet a favorable target for future transmission spectroscopy follow-up observations. We reexamine the correlations in radius, equilibrium temperature, and metallicity of the close-in gas giants and find hot Jupiter-mass planets to exhibit the strongest dependence between radius and equilibrium temperature. We find no significant dependence in radius and metallicity for the close-in gas giant population. Show more