NGC 4523
NGC 4523 is a Magellanic [spiral galaxy] located about 35 to 50 million light-years away in the constellation Coma Berenices. It was discovered by astronomer Heinrich d'Arrest on April 19, 1865. NGC 4523 is a member of the Virgo Cluster. A distance of for NGC 4523 was derived from using yellow supergiants in the galaxy as standard candles.
On December 23, 1999, a Type [II supernova] designated as SN 1999gq was detected in NGC 4523.