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.
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Related terms
- Asterism
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.
- Zodiac
The band of sky along the ecliptic where the Sun, Moon and planets move. The ecliptic actually crosses 13 constellations, including Ophiuchus. Astrology’s “signs” no longer match the constellations, shifted by precession: astrology is not a science.
- 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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