M74 is a beautiful face-on spiral galaxy located in the constellation of Pisces. It is an archetypal example of a Grand Design spiral galaxy that was discovered by Pierre Méchain sometime during September 1780. Méchain then reported his discovery to Charles Messier, who subsequently determined its position and catalogued it on October 18, 1780. With a magnitude of +9.4, M74 is not a faint galaxy but it does suffer from low surface brightness and can be difficult to locate even with just a hint of light pollution. As a result, it is widely regarded as one of the more difficult Messier objects.
M74 is located in the barren star fields of Pisces. Despite Pisces being the 14th largest constellation in the sky (889 sq. degrees), it contains no bright stars. The brightest star Eta Piscium (η Psc) is only of magnitude +3.6. Luckily this star is a perfect marker; M74 lies only 1.5 degrees to the east-northeast. To pinpoint Eta Piscium, start in the adjacent constellation of Aries. First locate the constellations two brightest stars, Hamal (mag. +2.0) and Sheratan (mag. +2.6). Then imagine a line connecting Hamal to Sheratan and extend this line in a southwest direction for just over 7.5 degrees. This leads directly to Eta Piscium. The galaxy is best seen during the months of October, November and December.
Observationally, M74 is a very difficult binocular object. In 10x50 binoculars it's extremely challenging with dark, light pollution free skies a must and even then it may still be invisible. At best it appears only as a very faint smudge of light. Larger 20x80 binoculars make the task easier with M74 appearing as a dim small round patch of nebulosity without detail. The view through a small 100mm (4-inch) telescope at low magnification is slightly improved; the core region of the galaxy is visible surrounded by a very faint fuzzy halo. With a 200mm (8-inch) telescope the halo is more pronounced and appears larger. The halo of course is the beautiful spiral arms, evidence of which can be glimpsed in larger telescopes of the order of 300mm (12-inch) aperture or greater. In appearance, M74 looks like a smaller version of M33 The Triangulum Galaxy but with a more defined nucleus.
The galaxy is located 32.5 million light-years from Earth and has a diameter of about 95,000 light-years, similar to that of the Milky Way. It has a large apparent size of 10.5 x 9.5 arc minutes. In 2002 and again in 2003, supernovae were discovered in M74. This first supernova brightened up to mag. +12.3, the second to mag. +13.2.
Interestedly, M74 was the subject of a mistake made by Sir John Herschel in his General Catalogue (GC), published in 1864. In it Herschel mysteriously catalogued M74 as a globular cluster, an error that was also carried over into the subsequent New General Catalogue (NGC).
M74 is a beautiful spectacular face-on spiral galaxy with a low surface brightness. It therefore can be a difficult object to locate visually, but is rewarding once found. The full glory and majesty of M74 is revealed in images and photographs.
M74 Data Table
|Object Type||Spiral galaxy|
|RA (J2000)||01h 36m 42s|
|DEC (J2000)||15d 47m 03s|
|Apparent Size (arc mins)||10.5 x 9.5|