HATS-17b: A Transiting Compact Warm Jupiter in a 16.3 Days Circular Orbit

TL;DR

HATS-17b is a unique transiting warm Jupiter with a 16.3-day orbit, notable for its high density, compact size, and potential for detailed follow-up studies due to its brightness.

Contribution

This is the first transiting warm Jupiter discovered by the HATSouth network, expanding the known population of such planets with detailed characterization potential.

Findings

HATS-17b has a 16.3-day circular orbit.

It has a high density suggesting a large heavy element core.

It is one of the brightest transiting warm Jupiters available for follow-up.

Abstract

We report the discovery of HATS-17b, the first transiting warm Jupiter of the HATSouth network. HATS-17b transits its bright (V=12.4) G-type (M$_{\star}$=1.131 $\pm$ 0.030 M$_{\odot}$, R$_{\star}$=1.091$^{+0.070}_{-0.046}$ R$_{\star}$) metal-rich ([Fe/H]=+0.3 dex) host star in a circular orbit with a period of P=16.2546 days. HATS-17b has a very compact radius of 0.777 $\pm$ 0.056 R$_J$ given its Jupiter-like mass of 1.338 $\pm$ 0.065 M$_J$. Up to 50% of the mass of HATS-17b may be composed of heavy elements in order to explain its high density with current models of planetary structure. HATS-17b is the longest period transiting planet discovered to date by a ground-based photometric survey, and is one of the brightest transiting warm Jupiter systems known. The brightness of HATS-17b will allow detailed follow-up observations to characterize the orbital geometry of the system and the atmosphere of the planet.