What is XPoSat, India's 1st mission to study black holes that was launched today?

ISRO has announced successful launch of India's first dedicated polarimetry mission to study dynamics of bright astronomical X-ray sources like black holes, neutron stars, active galactic nuclei, etc. The XPoSat (X-ray Polarimeter Satellite) is the world's second such mission. It aims to understand emission processes from astronomical sources by studying their degree and angle of polarisation.