A bright supernova appeared in the fairly “nearby” (24 million light years) Whirlpool galaxy (M51) in late August 2011. It was named Supernova 2011dh. Images taken using the Hubble Space Telescope of the galaxy before the explosion showed a star at the position of the supernova, but astronomers argued whether this was indeed the star that exploded. Now we know!
New images taken once the supernova has faded reveal that the star is gone. This animation is made of B, V and R band images taken before – and long after – the supernova explosion using the 2.6m Nordic Optical Telescope on La Palma. The zoomed in part is blinked to highlight the star that is now gone (click on the image to enlarge it).
– It is pretty cool that we can spot a single star, among 100 billion stars in a remote galaxy, says Jesper Sollerman, that participated in the study. This is because supernovae come from the most massive and luminous stars we know of.
The paper, lead by M. Ergon, that describes the supernova in some detail is now submitted to Astronomy & Astrophysics, and it is also available from the ArXiv.