WASP-40b: independent discovery of the 0.6-Mjup transiting exoplanet HAT-P-27b

TL;DR

This paper reports the independent discovery of the exoplanet WASP-40b, a hot Jupiter transiting a late G or early K star, confirming previous findings and adding to the population of short-period transiting planets.

Contribution

It provides an independent confirmation of WASP-40b's existence and parameters using WASP photometry and SOPHIE radial velocities, supporting previous HATnet results.

Findings

WASP-40b is a 0.6 Mjup hot Jupiter with a 3.04-day orbit.

The host star is a late G or early K-type star with slightly above solar metallicity.

The planet's properties are consistent with known hot Jupiters, reinforcing the period distribution.

Abstract

From WASP photometry and SOPHIE radial velocities we report the discovery of WASP-40b (HAT-P-27b), a 0.6 Mjup planet that transits its 12th magnitude host star every 3.04 days. The host star is of late G-type or early K-type and likely has a metallicity greater than solar ([Fe/H] = 0.14 +/- 0.11). The planet's mass and radius are typical of the known hot Jupiters, thus adding another system to the apparent pileup of transiting planets with periods near 3 to 4 days. Our parameters match those of the recent HATnet announcement of the same planet, thus giving confidence in the techniques used. We report a possible indication of stellar activity in the host star.