M74: Galaxy in Pisces
January 2012 :
Last month, we explored the galaxy M33, a notoriously difficult telescopic target due to its extremely low surface brightness. For the same reason, M74 is even more challenging; in fact, many consider it the most visually demanding of all the Messier objects. Upon discovering this galaxy in 1780, the French astronomer Pierre Mechain remarked, “It is quite broad, very dim, and extremely difficult to observe.” M33 is commonly described as a 6th magnitude star defocused until its light is spread over an area twice the apparent diameter of the moon. With M74, we have a magnitude 9.5 star whose light is extended over an area 10 arc-minutes across. No wonder M74 bears the nick-name the “Phantom Galaxy!”
The good news is that M74 can be captured if you know where to look and (most importantly!) observe from a clear, dark sky. In fact, I’ve glimpsed it (albeit faintly) with a 3-inch f/6 reflector. Viewed with averted vision, it appeared as a ghostly blob of light. The key was in conducting my search with a low power (30X) eyepiece.
M74 is situated 15 degrees south of its elusive cousin and 1 ½ degrees east and slightly north of the 4th magnitude star eta (η) Piscium (refer to the accompanying finder chart). In size, it’s essentially an equal to our Milky Way. M74 lies about 32 million light years away, about 15 times more distant than M33.
