The galaxy M82 is to the left. The VLA image (top left) shows the supernova taken in May 2008. The high-resolution image (lower right) shows an expanding shell at the scale of a few light days.
Credit: Milde Science Communication/NASA/ESA/STScI/AURA/A. Brunthaler/MPIfR
"This cosmic catastrophe shows that using our radio telescopes we have a front-row seat to observe the otherwise hidden universe," added co-author Heino Falcke of Radboud University, Nijmegen in the Netherlands.
Radio emissions are only detected from 'core collapse' supernovas, where the core of a massive star collapses and produces a black hole or a neutron star.
4% the speed of light
It is produced when the shock wave of the explosion propagates into dense material surrounding the star; usually material that was shed from the massive progenitor star before it exploded.
By combining data from the 10 telescopes of the Very Long Baseline Array (VLBA), the VLA, the Green Bank Telescope in the U.S., and the Effelsberg 100-metre telescope in Germany, the team was able to produce images that show a ring-like structure expanding at more than 40 million km/h or 4% of the speed of light, which is typical for a supernova.
"By extrapolating this expansion back in time, we can estimate the explosion date [to be] late January or early February 2008," said Brunthaler.
With the Max Planck Institute For Radio Astronomy.
