Deep Sky Objects

Deep sky objects (DSO's) are where it is at in astronomy.  Most beginning astronomers fall in love with the planets, but quickly get bored and want more.  There are only a handful of planets to see, but there are thousands of deep sky objects, which include elliptical galaxies, spiral galaxies, emission nebulae, planetary nebulae, supernova remnants, open clusters, globular clusters.  Most observing of DSO's is done at low magnification. 

Most DSO's are faint and can not be seen with the naked eye, especially in light polluted skies.  In dark skies however, there are some notable exceptions, such as M31 (Andromeda Galaxy).  To observe a DSO, you want to start with a low power eyepiece.  Generally, you will stay with a low power eyepiece, but sometimes you will want a bit more magnification.  Sometimes a DSO is so small, such as a small planetary nebula, that it barely looks bigger than a star, and others are so big they don't fit into your eyepiece.  Filters can be useful.  If you are in light polluted skies, a light pollution filter (LPR) can be extremely helpful.  They help block out the light waves emitted by most streetlights and make for better contrast.  Other deep sky objects, such as the Horsehead Nebula and the California Nebula require a hydrogen beta filter, or you can forget seeing them, especially with anything less than a 20" scope.  An OIII filter is also very helpful in viewing other nebulae.  Do not expect to see detail and color like you see in photographs.  Our eyes are not sensitive enough to pick up color in deep space objects.  They will generally look like "faint fuzzys".

There are a number of catalogues which list and categorize deep sky objects, such as Messier, New General Catalogue (NGC), Abell, and Caldwell.  There are many other catalogues, however, Coolscopes.com has not put them up on this site.  

Click on a link or picture below to learn more about these deep space objects.

Star Clusters

Nebulae

Galaxies