Colloq Abstract - Das
August 8
11:00am Mountain
Bernali Das (NCRA/TIFR)
Coherent radio emission from hot magnetic stars
Abstract
Coherent radio emission from hot main-sequence magnetic stars is an emerging field in astronomy. The phenomenon was discovered in the year
2000 from the Ap star CU Vir, and the emission mechanism was identified to be Electron Cyclotron Maser Emission (ECME). With the GMRT, we discovered the second star to exhibit similar emission. This discovery came 17 years after the discovery in CU Vir and brought up the question of whether this is a common phenomenon among a class of hot magnetic stars. We subsequently started a survey with the upgraded GMRT (uGMRT) to search for similar stars so that we can eventually identify the properties that define the class of hot magnetic stars exhibiting ECME.
In the last one year we have made another two confirmed discoveries and with these, the number of hot magnetic stars exhibiting coherent radio emission stands at 5. In my talk, I will describe the results of our survey and some potential issues that can affect the observation of this emission. I will also discuss certain characteristics of ECME and how we can extract information about various stellar properties by studying these characteristics over a wide range of frequencies at multiple epochs.
