Charles Messier, 1790-1817, was a serious comet hunter. Intrigued by the night sky he particularly liked looking for things that moved. Early telescopes, though crude, had him bumping into objects that looked like comets but didn’t move. He noticed a few of them on contemporary catalogs of the sky. From his brother, Hyacinth, he learned administrative methods while recovering from a broken leg. The strict attention to detail required by his brother taught him valuable skills for observing and recording his finds. By 1774, at only 14 years of age, he found his first comet. Soon after, he began cataloging fixed objects which, at the time, could not be resolved beyond their comet-like appearance. With the available optics of the day, he created a list of 110 deep sky objects.
Thanks to Charles, recent astronomical adventures include the Messier Marathon which takes place every spring when all 110 objects can be hunted down in a given night. If you attempt the marathon household binoculars, a 7x50 or 10x50 will reward you with a look at 60 of those fuzzies (a 20x80 is needed for all 110). You won’t see details of the nebulae or galaxies, but some star clusters are resolvable. Messier himself used both a 2ft focal length refractor and a 4.5 ft focal length Newtonian telescope.
Deep sky objects fall into several categories according to astronomers. They are
Nebulae
Star Clusters
Galaxies
Each category has its own sub-classifications:
Nebulae are diffuse, meaning spread out all over or planetary, round like a planet. They are also known as reflection or emission nebulae depending on light emitted from within the nebula, or reflected light from a nearby star.
Clusters can be globular, grouped in a tight ball or open and spread out
Galaxies are spiral or irregular. Spiral and irregular galaxies house globular or open cluster in star forming regions.
Next week more on deep sky objects.
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