Rektascenzija	12 : 21.9 (u:m)
Deklinacija	+04 : 28 (sto:m)
Razdalja	60000 (*1000 sv.l.)
Vizual. magnituda	9.7 (mag)
Zorni kot	6x5.5 (loc min)

M61 was discovered by Oriani on May 5, 1779 when following the comet of that year, 6 days before Charles Messier's discovery, who had seen it on the same day as Oriani but mistaken it for the comet. Messier mistook it 2 times more until he realized that it did not move. As for a small number of others, this object was assigned an own number, H I.139, by William Herschel, who normally avoided to give own numbers to Messier's objects.

M61 is one of the larger galaxies in the Virgo cluster; its 6 arc minutes of diameter correspond to about 100,000 light years, similar to the diameter of the Milky Way galaxy. Its 10th magnitude corresponds to an absolute magnitude of -21.2.

Three supernovae have been observed in M61: 1926A (12.8 mag), 1961I (mag 13), and 1964F (mag 12). The Supernova 1961I appeared in the spiral arms, about 82" from the center, and was photographed by the Lick observatory, see e.g. Burnham (you may also order this image from them as slide or print).

Vec posnetkov M61