Patterns and regions of sky
In everyday conversation a constellation can mean a familiar pattern made from stars. Astronomers also use the word for a precisely defined region of sky. The International Astronomical Union recognises 88 constellations whose boundaries cover the entire celestial sphere.
Well-known patterns do not always correspond to an entire constellation. The Big Dipper, for example, is a distinctive pattern within Ursa Major. A pattern like this is often called an asterism.
Are the stars close together?
Not necessarily. Stars that look adjacent from Earth may be separated by enormous distances. The two-dimensional pattern is a view from our particular place in space, and it changes very slowly as stars move.
How to begin stargazing
- Check the weather and choose a safe place away from bright lights.
- Use a sky chart set to your location, date and time.
- Start with a recognisable pattern such as Orion’s Belt or the Big Dipper.
- Give your eyes time to adapt to darkness and compare the chart with the sky.
Different stars are visible at different times of year and from different latitudes. No single chart describes the sky everywhere at once.
Names, stories and science
Communities around the world have described the same sky through many traditions. A commercial dedication is a personal gesture; it does not change an official star name. Read our star dedication guide for a clear explanation.