A uGMRT search for radio emission from planets around evolved stars

Abstract

ABSTRACT In this work, we present the results from a study using the Giant Meterwave Radio Telescope (GMRT) to search for radio emission from planets around three evolved stars namely α Tau, β UMi, and β Gem. Both α Tau and β UMi host massive ∼ 6 MJ mass planets at about ∼1.4 au from the central star, while β Gem is host to a 2.9 MJ mass planet at 1.7 au from the host star. We observe α Tau and β UMi at two upgraded GMRT bands: band 3 (250–500 MHz) and band 4 (550–900 MHz). We also analysed the archival observations from β Gem at 150 MHz from GMRT. We did not detect any radio signals from these systems. At 400 MHz, the 3σ upper limit is 87 μJy beam−1 for α Tau b and 77.4 μJy beam−1 for β UMi b. From our observations at 650 MHz, we place a 3σ upper limit of 28.2 μJy beam−1 for α Tau b and 33.6 μJy beam−1 for β UMi b. For β Gem b, at 150 MHz, we place an upper limit of 2.5 mJy. At 400 and 650 MHz, our observations are the deepest radio images for any exoplanetary system.