Messier 61: Barred Spiral Galaxy in Virgo

M61 is a face-on spiral galaxy in the southern part of the Virgo Cluster, away from the crowded region around Markarian's Chain. It is one of the larger galaxies in the cluster and is best known for the number of supernovae seen in it.

What it is

M61 is a barred spiral galaxy about 55 million light-years away. Its 6-arcminute size works out to roughly 96,000 light-years, close to the size of the Milky Way. We see it nearly face-on, with a short bar and two main spiral arms. Its center is a starburst region, forming new stars at a high rate. Seven supernovae were recorded in M61 between 1926 and 2014, the most of any Messier galaxy at that time.

When to see it

M61 is a spring object. It is highest around midnight in early April and well placed in the evening from April into June. From about 40°N it climbs to about 54° in the south. It lies close to the celestial equator, so it is well placed from the Southern Hemisphere too.

How to find it

Find the "bowl" of Virgo, the bright stars Beta, Eta, Gamma, Delta and Epsilon Virginis. Start at Eta Virginis (Zaniah), on the west side of the bowl, and move about 5° due north. There you reach two 5th-magnitude stars, 16 and 17 Virginis, about 2° apart. M61 lies between them, about 1° north-northeast of 16 Virginis and less than 1° south of 17 Virginis. From M61, M49 is about 4° north-northeast.

What you will see

M61 is a faint galaxy. A small telescope under dark skies shows a round, dim glow with a slightly brighter center, easy to pass over at low power. A 200 mm telescope shows a small bright core and, on a good night, a mottled halo where the spiral arms are; with averted vision you may sense the arms or the bar. Larger scopes show the arms more clearly. From suburban skies it is hard to see in small instruments, so this is one to save for a dark site.

History

Barnaba Oriani discovered M61 on May 5, 1779, while following that year's comet. Charles Messier saw it the same night but thought it was the comet itself. Only on May 11 did he realize that the glow did not move, and he added it to his catalog. William Herschel later gave it his own catalog number when he observed it in 1786.