Hubble Finds Supernova Companion Star after Two Decades of Searching

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Using NASA’s Hubble Space Telescope, astronomers have discovered a companion star to a rare type of supernova. The discovery confirms a long-held theory that the supernova, dubbed SN 1993J, occurred inside what is called a binary system, where two interacting stars caused a cosmic explosion.

"This is like a crime scene, and we finally identified the robber," said Alex Filippenko, professor of astronomy at University of California (UC) at Berkeley. "The companion star stole a bunch of hydrogen before the primary star exploded."

SN 1993J is an example of a Type IIb supernova, unusual stellar explosions that contains much less hydrogen than found in a typical supernova.  Astronomers believe the companion star took most of the hydrogen surrounding the exploding main star and continued to burn as a super-hot helium star.

Read the full NASA press release