It's a bit like trying to find a needle in a haystack when looking for a star in a galaxy. Although hard to do, astronomers using images from the Hubble Space Telescope (HST) are doing just that, trying to find stars before they explode as supernovae. In 2006, supernova SN 2006bc was spotted in spiral galaxy NGC 2397, so astronomers got to work, sifting through previous images taken by the HST. They found that star, in the rising stage of brightness as it exploded. Usually we don't get to see this stage of a supernova, as we can't predict which star is going to blow. But retracing years of HST observational data, scientists are able to piece together the cosmic forensic evidence and see the star before it died…

SN 2006bc was seen in the spiral galaxy NGC 2397, located nearly 60 million light years from the Milky Way, back in 2006. There was no warning or any indication that that star was going to blow in that galaxy (after all, there's a lot out there), but Hubble's Advanced Camera for Surveys (ACS) captured the galaxy after it happenedhttp://www.universetoday.com/2008/04/05/supernova-precursor-discovered-in-spiral-galaxy-ngc-2397/#comment-17452