An easily recognised star pattern that is not an official constellation. The Plough (Big Dipper) in Ursa Major, the Summer Triangle (Vega, Deneb, Altair) and the W of Cassiopeia are examples. Asterisms are handy signposts for finding your way.
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Related terms
- Constellation
One of the 88 regions that have officially divided the sky since 1922–1930, each with its own borders, like counties on a map. The stars of a constellation are often unrelated, at very different distances. Their Latin names are used to label stars, such as Alpha Lyrae for Vega.
- Star hopping
The method of starting from an easy bright star and hopping from star to star, chart in hand, to the target. A finder or Telrad and the known size of its field help. It is slow at first, but it is how you learn the sky.
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