WASP-41b: A transiting hot Jupiter planet orbiting a magnetically-active G8V star

TL;DR

This paper reports the discovery and characterization of WASP-41b, a hot Jupiter orbiting a magnetically active G8V star, and discusses the star's activity and age in relation to the planet.

Contribution

It introduces a new method to analyze stellar activity signals and provides detailed parameters of a hot Jupiter around an active star.

Findings

WASP-41b has a mass of approximately 0.92 Jupiter masses.

The host star shows moderate chromospheric activity and an age of about 1.8 billion years.

The star's rotation period is 18.4 days, indicating its activity level.

Abstract

We report the discovery of a transiting planet with an orbital period of 3.05d orbiting the star TYC 7247-587-1. The star, WASP-41, is a moderately bright G8V star (V=11.6) with a metallicity close to solar ([Fe/H]=-0.08+-0.09). The star shows evidence of moderate chromospheric activity, both from emission in the cores of the CaII H and K lines and photometric variability with a period of 18.4d and an amplitude of about 1%. We use a new method to show quantitatively that this periodic signal has a low false alarm probability. The rotation period of the star implies a gyrochronological age for WASP-41 of 1.8Gyr with an error of about 15%. We have used a combined analysis of the available photometric and spectroscopic data to derive the mass and radius of the planet (0.92+-0.06M_Jup, 1.20+-0.06R_Jup). Further observations of WASP-41 can be used to explore the connections between the properties of hot Jupiter planets and thelevel of chromospheric activity in their host stars.