                        Astronomy Picture of the Day

    Discover the cosmos! Each day a different image or photograph of our
      fascinating universe is featured, along with a brief explanation
                    written by a professional astronomer.

                                2025 July 31

                        Supernova 2025rbs in NGC 7331
              Image Credit: Ben Godson (University of Warwick)

   Explanation: A long time ago in a galaxy 50 million light-years away, a
   star exploded. Light from that supernova was first detected by
   telescopes on planet Earth on July 14th though, and the extragalactic
   transient is now known to astronomers as supernova 2025rbs. Presently
   the brightest supernova in planet Earth's sky, 2025rbs is a Type Ia
   supernova, likely caused by the thermonuclear detonation of a white
   dwarf star that accreted material from a companion in a binary star
   system. Type Ia supernovae are used as standard candles to establish
   the distance scale of the universe. The host galaxy of 2025rbs is NGC
   7331. Itself a bright spiral galaxy in the northern constellation
   Pegasus, NGC 7331 is often touted as an analog to our own Milky Way.

                     Tomorrow's picture: pixels in space
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       Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
            NASA Official: Amber Straughn Specific rights apply.
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