Messier 74 (NGC 628) is a screw galaxy out of the top-drawer. This far-flung island universe yields weird images, its sweeping screw stovepipe stuff presented in the ‘grand-design’ manner. This term is reserved for face-on spirals characterised by prominent screw stovepipe that wrap virtually the nucleus in a malleate similar to the magnificent Whirlpool Galaxy (Messier 51), probably the typical grand-design spiral.Â
Messier 74’s has two, well-defined screw stovepipe that are less upturned than those of say Messier 101, flipside member of the grand diamond club, and a small yet unexceptionable nucleus. Messier 74 appears scrutinizingly totally face-on to our perspective, it stuff tilted yonder from us by just five degrees. This helps astronomers to hands study Messier 74’s screw arms. We have a front-row seat to trace pebbles lanes seen primarily in their inner region and young, hot undecorous star clusters and glowing pink, longish HII regions, sites of remoter star formation, seen dotted withal their unshortened length.
How to observe
Messier 74 (NGC 628) is located in the far eastern reaches of Pisces, the constellation whose western end, including its ‘Circlet’ asterism, lies to the south of the Great Square of Pegasus. M74 is located north of Pisces’ main line of stars which stretch from the Circlet to magnitude 3.8 Alrescha (alpha [α] Piscium) in its far south-east. It lies nearly 15 degrees north-west of Alrescha, but it may be easier to find by sweeping for it 10 degrees south-west of brighter Hamal (alpha Arietis, magnitude 2).
At mid-month, M74 culminates (is highest in the local southern sky) at a favourable upland of virtually 55 degrees at well-nigh 1am BST from southern England. It achieves a reasonable upland of whilom 30 degrees in the east-southeast between 9pm and 5am BST.Â
Messier 74 is a large galaxy which appears face-on to our line of sight. It covers 11 <M>x<M> 11 arcminutes across, well-nigh a third of the size of the full Moon, and has a catalogued magnitude of 9.2. Essentially, this ways the equivalent of the well-matured light of a magnitude 9.2 star is spread out over its unshortened face-on form, which unfortunately gives M74 a low surface brightness.Â
Low surface brightness
While deep-sky imagers of Messier 74 enjoy carte blanche, it’s often a far variegated story for visual observers confronting the galaxy. All face-on screw galaxies are misfortunate by low surface splendor to some degree, including the likes of the Whirlpool Galaxy, though Messier 74 has the unenviable reputation as perhaps the toughest visual target in the Messier catalogue. However, a pair of binoculars or a finderscope can reveal it as a fuzzy oval of light on a fine, moonless night at an observing site self-ruling from major light pollution. Use low powers when sweeping for M74 through a small telescope; an 80mm (~three-inch) refractor can show a circular patch well-nigh five arcminutes across.
Upgrading to a 200mm- (eight-inch-) vent telescope and ramping up the magnification reveals some mottling, this stuff the unresolved and faint traces of M74’s svelte and well-ordered screw stovepipe surrounding its small core. Present-day deep-sky images, preferably shot through long-focus telescopes, are breathtaking, displaying the galaxy at its photogenic best.