To accurately identify the stars or constellation you are observing and determine the distance between them, several factors need to be considered, such as your geographic location, the time and date of your observation, and the direction you are facing. Common constellations visible across many parts of the world include Orion, Ursa Major, and Cassiopeia.
Once you have the name of the constellation or individual stars, you can use star charts or astronomy software to gain more insights. For example, if you’re looking at Orion, notable stars include Betelgeuse, Rigel, and Bellatrix.
The concept of distance between stars in a constellation can be somewhat misleading, as constellations are essentially patterns projected on the celestial sphere from our viewpoint on Earth. Stars in a constellation may appear close together but can be vast distances apart in reality. For instance, the distance to Betelgeuse is about 642.5 light-years from Earth, while Rigel is about 860 light-years away. If you wish to know the distance between them, you would calculate it using their respective positions and distance figures in a three-dimensional space, often using parallax measurements and other distance-mapping tools astronomers use.
For a precise identification and analysis, using an astronomy app or software like Stellarium can be incredibly helpful, as it overlays star maps based on your unique viewing conditions.