Messier Sky

6/3/07 – 6/9/07
by C. Zaitz

It is my opinion that summertime is the very best time for evening sky watching, whether you are a casual looker, an interested observer or a hard-core “Messier object” junkie. I’ve been all three at various times, but summer is the time when we can spend more quality time outside at night, gazing upward, finding your “fix” in the stars. Beyond knowing the constellations, if you really want to get to know the universe, finding Messier objects is a good way to do it. (Messier doesn’t refer to the chaos of the sky, it’s the last name of French astronomer Charles Messi “ay.”)

Monsieur Messier was an observational astronomer at the end of the 18th century who was very interested in finding new comets. This was a popular past time for an astronomer seeking to be immortalized by getting a comet named after him. However, Messier was annoyed with the countless fuzzy clouds in space that were easily confused with fuzzy comets. Messier catalogued over 100 “nebulae,” which were thought to be some sort of cloud within the galaxy. He hoped to save himself and other comet hunters the confusion of wondering if the faint fuzzy was indeed a fame-inducing object, or merely another “cloud.”

The existence of other galaxies beyond the Milky Way was not known until William Herschel and others continued cataloguing the fuzzy objects. The Herschel General Catalogue of Nebulae, listing over 5,000 objects, gave way to the New General Catalogue (NGC) in 1888, which contained nearly 8,000. Soon their true nature became clear- these clouds were not of the Milky Way at all, but each a separate “island universe” like our own. And Messier’s catalogue of galaxies, nebulae and supernovae remnants gave him more fame than any comet would have. Amateur astronomers world-over know of Messier and his wonderful catalogue of deep space objects. The NGC does not immortalize its author, but contains Messier objects as well as many more interesting destinations for the observer with time and telescope on hand.

The summer skies hold many Messier objects, known by their “M” number. Many of them have very pretty nicknames. For example, M57 is the Ring Nebula, M101 is the Pinwheel Galaxy and M104 is the Sombrero Galaxy. Other nick names are not so lovely; such as the Blackeye galaxy (M64), the Crab Nebula (M1), and the Dumbbell Nebula (M27). Cute name or not, one of the most beautiful sights to see in the late spring and summer is M13, the lovely globular cluster of stars in Hercules. A globular cluster is a tightly packed group of older stars. In M13 there are estimated to be over a million stars in a sphere of space about 100 light years across. You can see the Hercules cluster with binoculars, but it truly is best seen through a telescope.

M57, the Ring Nebula in Lyra is also a pretty sight in a telescope. It is the first planetary nebula ever discovered. It looks like an ethereal smoke ring in the black sky, but it is the outer shells of a dying star, suffering the same fate as will our sun, in some 5 billion years.

There are many more such objects within view of a typical amateur telescope, and summer amateur group star parties are the best way to see these sights, and to get to know those folks who can help you discover the universe of Messier deep space objects.

Until next week, my friends, enjoy the view.