WASP-78b and WASP-79b: Two highly-bloated hot Jupiter-mass exoplanets orbiting F-type stars in Eridanus

TL;DR

This paper reports the discovery and characterization of two highly bloated hot Jupiter exoplanets, WASP-78b and WASP-79b, orbiting F-type stars, with detailed measurements of their masses, radii, and temperatures.

Contribution

It presents the first detailed parameters of WASP-78b and WASP-79b, including their sizes, masses, and temperatures, highlighting their bloated nature and extreme characteristics.

Findings

WASP-78b has a mass of 0.89 M_Jup and a radius of 1.70 R_Jup.

WASP-78b's equilibrium temperature is approximately 2350 K.

WASP-79b has a mass of 0.90 M_Jup and an uncertain radius between 1.70 and 2.09 R_Jup.

Abstract

We report the discovery of WASP-78b and WASP-79b, two highly-bloated Jupiter-mass exoplanets orbiting F-type host stars. WASP-78b orbits its V=12.0 host star (TYC 5889-271-1) every 2.175 days and WASP-79b orbits its V=10.1 host star (CD-30 1812) every 3.662 days. Planetary parameters have been determined using a simultaneous fit to WASP and TRAPPIST transit photometry and CORALIE radial-velocity measurements. For WASP-78b a planetary mass of 0.89 +/- 0.08 M_Jup and a radius of 1.70 +/- 0.11 R_Jup is found. The planetary equilibrium temperature of T_P = 2350 +/- 80 K for WASP-78b makes it one of the hottest of the currently known exoplanets. WASP-79b its found to have a planetary mass of 0.90 +/- 0.08 M_Jup, but with a somewhat uncertain radius due to lack of sufficient TRAPPIST photometry. The planetary radius is at least 1.70 +/- 0.11 R_Jup, but could be as large as 2.09 +/- 0.14 R_Jup, which would make WASP-79b the largest known exoplanet.