Messier 91 (also M91, NGC 4548 and PGC 41934) is a magnitude +11.0 barred spiral galaxy located 63 ±16 million light-years away in the constellation Coma Berenices.
The galaxy was discovered by French astronomer Charles Messier using a 10 cm (4 inch) refracting telescope on the 18th March 1781. The galaxy was independently discovered by William Herschel on the 4th April 1784.
Right Ascension 12h 35m 26.4s, Declination +14° 29' 47"
