Indian scientists have performed the most sensitive measurement of X-ray polarisation of the Crab pulsar, the rotating neutron star which is the main energy source of the nebula. <br/><br/>In a release issued by ISRO, the breakthrough was achieved using data from the CZT Imager instrument of the AstroSat satellite. These extraordinary results have been reported in a paper published on November 6 in the journal 'Nature Astronomy'. <br/><br/>The lead author of this paper Prof. Santosh Vadawale says that the measurements have, for the first time, enabled the study of polarization at different rotation phases of the pulsar. <br/><br/>This landmark measurement puts up a strong challenge to prevailing theories of high energy X-ray emission from pulsars.