Only a few supernovae have come from stars that we had images of before they were destroyed. But in this case, the star that exploded showed up in the Hubble Image. We now know that it was a red giant just barely large enough to make a supernova: about eight times the mass of our sun. If you watch the animation a few times, you can see which star was at the center of the explosion. That's the one!
Credit: NASA, ESA, W. Li and A. Filippenko (University of California, Berkeley), S. Beckwith (STScI), and The Hubble Heritage Team (STScI/AURA)