How to Observe a Star Cluster

Introduction

A star cluster is a group of stars that often formed together and are now attracted to one another as a result of their gravity. There are star clusters throughout the galaxy, many of which are still amidst massive nurseries where new stars are being formed. It's easy to observe some of the more prevalent star clusters if you know where to look, and with a telescope you can spot them regardless of where in the world you live.

Things You'll Need

• Star chart
• Telescope or binoculars

Steps

1 Step One

Know which type of cluster you wish to observe. Globular star clusters can contain hundreds to millions of stars and can be 30 or more light years in diameter (Omega Centauri, for example). Open clusters, on the other hand, are usually small with a handful of young, bright stars (the Pleiades in the constellation Taurus, for example).

2 Step Two

Consult a star chart or astronomy software or use the Internet to find the coordinates of the star cluster you wish to observe. There are plenty of websites maintained by astronomy enthusiasts that contain databases of star cluster coordinates.

3 Step Three

Set your telescope to point in the direction of the star cluster you wish to observe. Celestial coordinates are given in terms of Right Ascension (left or right along the horizon) and Declination (up and down along the circle of the sky).

4 Step Four

Adjust the declination setting on your telescope above or below the ecliptic (the path the sun appears to follow as the Earth spins). Coordinates with negative values are considered below the ecliptic, but not necessarily below the horizon.

5 Step Five

Turn the telescope to face the proper point of right ascension. It is important to remember that right ascension actually tracks left across the sky as the coordinate numbers increase.

6 Step Six

Use astronomy software to point your telescope toward the star cluster without having to calibrate its position yourself. Many astronomy software suites are capable of automatically adjusting the telescope to point at observable objects.

7 Step Seven

Choose a place for the telescope that has less ambient light. City lights and other light pollution can limit the effectiveness of the telescope.