For example, Orion has two really bright stars: Rigel, a blue supergiant that is the left foot of the Hunter, and Betelgeuse, a red supergiant that is the right shoulder. In the sky, they are only separated by 18.29°, but in space Rigel is 260 pc from Earth and Betelgeuse is 197 pc from Earth. Same area of the sky, but really far apart in space.
From APOD
Credit & Copyright: Matthew Spinelli
Betelgeuse is also part of something called an asterism: a smaller group of stars in the same general area in the sky that can either be a part of a constellation, or stars that are in other constellations. The asterism to which Betelgeuse belong is called the Winter Triangle along with Sirius (the Dog Star, the brightest star in Canis Major) and Procyon (the brightest star in Canis Minor).
Winter Triangle
Procyon, Betelgeuse and Sirius form the Winter Triangle.
Credit: StarryNightEducation
Remember the zodiac is made up of thirteen constellations. In all, there are 88 recognized constellations in the nighttime sky. I am not going to list them all here, but they can easily be found by using your favorite search engine to find them listed. Constellation names are used to actually describe stars in terms of what constellation you may find them. For example, α Centauri (one of the closest stars to our Sun) is found in the constellations Centaurus, hence Centauri. Rigel is also known as β Orionis and Betelgeuse is α Orionis. (I'll explain what the Greek letters before a constellation name means - Bayer designation).
Other example of asterisms include the Big Dipper and the Little Dipper, which are smaller portions of the constellations Ursa Major (Big Bear) and Ursa Minor (Little Bear), respectively. How many other asterisms do you know of?
