Astronomy for Beginners

Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.

Astronomy Dictionary
Optical double star

An optical double star is actually two stars that appear to be close to each other on the sky. In fact they are not at all related and appear close only because they lie close to each other along our line of sight.

Accretion disc

A disc of interstellar material around a celestial object, such as a star or a black hole, that has formed by matter being attracted by its gravitational pull.

Ocular adjustment

Increasing or decreasing the distance between the two eyepieces (which can also be called the ocular lenses) in a pair of binoculars.

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