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.