Search for radio emission from the exoplanets Qatar-1b and WASP-80b near 150 MHz using the Giant Metrewave Radio Telescope

TL;DR

This study used the GMRT to search for radio emissions from two nearby hot exoplanets near 150 MHz but found no signals, setting deep upper limits and ruling out certain sources nearby.

Contribution

First targeted radio observations of Qatar-1b and WASP-80b at 150 MHz, providing the deepest limits to date and clarifying the nature of nearby radio sources.

Findings

No radio emission detected from the exoplanets.

Set 3-sigma upper limits of 5.9 and 5.2 mJy.

Resolved a nearby radio source as extragalactic.

Abstract

We present radio observations made towards the exoplanets Qatar-1b and WASP-80b near 150~MHz with the Giant Meterwave Radio Telescope. These targets are relatively nearby irradiated giant exoplanets, a hot Jupiter and a hot Saturn, with sizes comparable to Jupiter but different masses and lower densities. Both the targets are expected to host extended H/He envelopes like Jupiter, with comparable or larger magnetic moments. No radio emission was detected from these exoplanets, with 3sigma limits of 5.9 and 5.2 mJy for Qatar-1b and WASP-80b, respectively, from these targeted observations. These are considerably deeper limits than those available for exoplanets from wide field surveys at similar frequencies. We also present archival VLA observations of a previously reported radio source close to Vir 61 (which has three exoplanets). The VLA observations resolve the source, which we identify as an extragalactic radio source, i.e. a chance association with Vir 61. Additionally, we cross-match a recent exoplanet catalogue with the TIFR GMRT Sky Survey ADR1 radio catalogue, but do not find any convincing associations.