Deep Sky Objects (DSO's).

What are they?
All images by Doug Bock

When astronomers look at objects in our solar system, such as Planets, Asteroids, Comets, the Moon and moons around other Planets, they are NOT looking at deep sky objects, because they are within our solar system.

 Jupiter

Saturn

Comet Hale-Bopp

Deep Sky Objects are objects that are NOT in our Solar system. They can be in our galaxy, such as nebulas and clusters. Our galaxy is a deep sky object too, the Milky Way. This is where most of the objects we talk about are located. The other galaxies in the universe are like ours but are very far away.

Our Galaxy - The Milky Way

Within our galaxy there are objects that astronomers call Globular Clusters. These are groupings of stars that look like a big ball of stars, and are gravitationally associated with each other. Some have 100,000 stars in them. These Globular Clusters are all around the outside part of the galaxy, in what astronomers call the Halo of the galaxy.

M13 is a globular cluster

There is another type of cluster called an open cluster. These are groupings of younger stars that are more loosely associated with each other or can appear to be associated with each other but aren't really. Can you see the difference between the 2 types of clusters?

M38 is an open cluster

Also within our galaxy there are objects that astronomers call Nebula. Nebulas are clouds of gas or dust that float around the galaxy, sometimes associated with new star clusters or old stars that have exploded. There are several types of nebula. Emission, reflection, planetary, and dark nebula. 

Crab Nebula

These images are examples of Planetary nebula, which are usually the remnants of Nova.

The Dumbbell Nebula

Notice that there is a nice donut shape to this planetary nebula. The shape of these types of nebula depend on the shape of the explosion as the star goes nova.

The Ring nebula

M42 is the Orion Nebula and this is an example of a reflection and emission Nebula. Young stars start in nebulas like this. These nebulas are called stellar nurseries, because the gas is compressing together due to gravity, and when dense enough, will form a proto-star.

Orion Nebula

The Horse head nebula is an example of a Dark Nebula that obscures the reflection and emission nebulas behind it. This is Dark Matter, which is made up mostly of dust particles.

Horse Head Nebula.

The last types of object on the list for this discussion are galaxies.

Galaxies are objects made up of billions of stars, which are gravitationally bound together. These objects are millions to billions of light years away.

M33 - Spiral Galaxy

A light year is the distance light will travel in 1 year. Galaxies are more difficult to see since they are so far away.

M74 - Spiral Galaxy

Galaxies also have many shapes. Some of these names are Spiral, Elliptical, Barred and Irregular galaxies.

Galaxies can face us in many different orientations. Face on, partially face on, and edge on.

NGC891 - Edge On Spiral

Finally, galaxies can be in Clusters such as the Stephan's Quintet grouping of galaxies. Groupings like this can be found through large telescopes, and are quite plentiful, but distant to us.

Stephan's Quintet