25 April 2013

The "Big Dipper" is an "asterism" - not a constellation

This grouping of stars is one of the few things that has likely been seen, and will be seen, by every generation. The Big Dipper is not by itself a constellation. Although part of the constellation of the Great Bear (Ursa Major), the Big Dipper is an asterism that has been known by different names to different societies.
Text and image from NASA's Astronomy Photo of the Day
Asterisms are sub- or supersets of constellations which build a constellation itself, or a group of stars, physically related or not.
Here is a list of dozens of asterisms (such as the "belt of Orion.")

You (re)learn something every day.


  1. Constellations are defined by the society that recognizes them, though, aren't they? You'd think that the set of constellations was evolving with usage over time, like language... It's already true that in different cultures the list of constellations is distinct. In what way is "The Big Dipper" not a modern American constellation (since we don't seem to really recognize Ursa Major anymore?)

  2. Adding to the thoughts on society and constellations; it's only in the western world/northern hemisphere that the big dipper is the first constellation you look for in the sky/teach to your kids/is iconic. On the southern hemisphere, for example, the Southern cross is much more likely to be used as an example in a post like this. Just a thought..


Related Posts Plugin for WordPress, Blogger...