Xposat

• India’s space agency, ISRO, is preparing to launch its first polarimetry mission, XPoSat, by the end of the year.
• The mission will study bright astronomical X-ray sources and provide vital information on the nature and behaviour of celestial objects.
• XPoSat is India’s first space mission to measure the polarisation of light and will help scientists understand emissions from black holes, neutron stars, and other challenging astronomical sources.
  • This will be the second polarimetry mission in the world, following NASA’s IXPE mission.
• The mission will carry two payloads —
  • POLIX (Polarimeter Instrument in X-rays) which will measure the polarimetry parameters including the degree and angle of polarization, in medium X-ray energy range of 8-30 keV photons of astronomical origin, and
  • XSPECT (X-ray Spectroscopy and Timing) payload which will give spectroscopic information in the energy range of 0.8-15 keV.

ABOUT POLARIMETRY

• Polarimetry is a powerful tool that allows astronomers to infer information about celestial objects, from passing comets to distant galaxies.
• The polarimetry measurements add two more dimension to our understanding,
  • The degree of polarization is the proportion of an electromagnetic wave that is polarized while
  • the angle of polarization is the angle at which light of a certain polarization is perfectly transmitted through a transparent surface.
• It is an excellent diagnostic tool to understand the emission processes from astronomical sources.