Astronomers using the Cosmic Origins Spectrograph and Wide-Field Camera 3 aboard NASA’s Hubble Space Telescope have finally discovered a companion star to the rare Type IIb supernova SN 1993J. This is an artist’s impression of SN 1993J. Image credit: NASA / ESA / G. Bacon, STScI. SN 1993J happened in M81, a galaxy located in the constellation Ursa Major, about 11 million light-years away. First detected in 1993, the explosion was the nearest...
