NASA`s NuSTAR reveals mystery of how stars explode

Astronomers - with the help of NASA`s, high-energy X-ray observatory,NuSTAR - have finally unravelled one of the biggest mysteries in astronomy, of how stars blow up in supernova explosions.

Zee Media Bureau/Liji Varghese

Washington: Astronomers - with the help of NASA`s, high-energy X-ray observatory, Nuclear Spectroscopic Telescope Array (NuSTAR) - have finally unravelled one of the biggest mysteries in astronomy, of how stars blow up in supernova explosions. The first map created of radioactive material in a supernova remnant named Cassiopeia A (Cas A), reveal how shock waves are likely to rip apart massive dying stars. Cassiopeia A was a star more than eight times the mass of our sun, which blew up as a supernova, leaving a dense stellar corpse and its ejected remains. NuSTAR is the first telescope capable of producing maps of radioactive elements in supernova remnants. In Cas A`s case, the element is titanium-44, which has an unstable nucleus produced at the heart of the exploding star. The supernova explosion`s light arrived on Earth about 350 years ago, but even today there`s still plenty of titanium-44 to be observed. The NuSTAR map of Cas A shows the titanium concentrated in clumps at the remnant`s center and points to a possible solution to the mystery of how the star met its demise. When researchers simulate supernova blasts with computers, as a massive star dies and collapses, the main shock wave often stalls out and the star fails to shatter. The latest findings strongly suggest that the exploding star literally sloshed around, re-energizing the stalled shock wave and allowing the star to finally blast off its outer layers. NuSTAR was launched in June 2012 and consists of an instrument with two telescopes that focusses high energy X-ray light. The findings are published in the journal Nature. Image Courtesy: NASA/JPL-Caltech/CXC/SAO