2024MNRAS.529.1161N

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 M_J mass planets at about ∼1.4 au from the central star, while β Gem is host to a 2.9 M_J 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.