A uGMRT search for radio emission from planets around evolved stars

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 $\hat{I}\pm$~Tau, ${\hat{I}}^2$~UMi, and ${\hat{I}}^2$~Gem. Both $\hat{I}\pm$~Tau and ${\hat{I}}^2$~UMi host massive $\sim$ 6 $M_J$ mass planets at about $\sim$1.4 au from the central star, while ${\hat{I}}^2$~Gem is host to a 2.9 $M_J$ mass planet at 1.7 au from the host star. We observe $\hat{I}\pm$~Tau and ${\hat{I}}^2$~ UMi at two u(upgraded)GMRT bands; band~3 (250-500~MHz) and band~4 (550-900~MHz). We also analyzed the archival observations from ${\hat{I}}^2$ Gem at 150~MHz from GMRT. We did not detect any radio signals from these systems. At 400~MHz, the 3$\ddot{I}ƒ$ upper limit is 87 $\hat{I}¼$Jy/beam for $\hat{I}\pm$~Tau~{b} and 77.4 $\hat{I}¼$Jy/beam for ${\hat{I}}^2$~UMi~{b}. From our observations at 650~MHz, we place a 3$\ddot{I}ƒ$ upper limit of 28.2 $\hat{I}¼$Jy/beam for $\hat{I}\pm$~Tau~b and 33.6 $\hat{I}¼$Jy/beam for ${\hat{I}}^2$~UMi~b. For ${\hat{I}}^2$ Gem b, at 150~MHz, we place an upper limit of 2.5 mJy. At 400~MHz and 650~MHz, our observations are the deepest radio images for any exoplanetary system.

9 pages, 6 figures, accepted at MNRAS