Astronomers Watch a Supernova and See Reruns

Dennis Overbye, writing for the NYT:

It’s “Groundhog Day” in the cosmos.

In the 1993 Bill Murray movie, a weatherman finds himself reliving the same day over and over again. Now astronomers using the Hubble Space Telescope say they have been watching the same star blow itself to smithereens in a supernova explosion over and over again, thanks to a trick of Einsteinian optics.

The star exploded more than nine billion years ago on the other side of the universe, too far for even the Hubble to see without special help from the cosmos. In this case, however, light rays from the star have been bent and magnified by the gravity of an intervening cluster of galaxies so that multiple images of it appear.

What’s wild is that the images can appear decades apart. Don’t skip the accompanying video — it’s great.

★ Friday, 6 March 2015