Image Credits

How do the stars get names. I mean did the same people name them. Also how many stars are there. A lot I know but do you have the answer?

Most of the brightest stars are named after characters in the mythology from various cultures. Many of them (like the planets) therefore have different names depending on where you are in the world. They were often named in pre-history by our ancestors who gazed at the stars trying to find patterns and stories in what they saw (this is also where the names for the visible planets and the constellations came from).

Modern astronomers have given the stars new names so that they can keep track of them more easily. Stars are named for the constellation that they lie in with the brightest star in a constellation being alpha and so on throught the greek alphabet. For example, Betelguese which is the brightest star in the constellation Orion, is also called Alpha Orionis.

There is a nice website on the names of stars at The constellations and their stars.

Stars that are discovered today are in general named for where they are in the sky or the person who found them, which gives them really ugly names like:
Luyten 726-8A
BD +5deg 1668
Kruger 60 A

Once they run out of Greek letters in a constellation, astronomers also use numbers (eg. 51 Pegasi - a famous star because of the planets around it). Variable stars are called things like RR Lyrae (in Lyre) or TT Arietis, in order of discovery. AA is the first variable star in a constellation, then AB; when they reach ZZ they start with number 677, because there are 676 possible ordered pairs of Latin letters.

There are probably other ways that stars are names. Each star usually has more than one name which astronomers have to keep track of in the information that they keep on it.

Some 200 to 300 stars were named in the past (roughly between the first and fifteenth centuries CE); these are the ones with (in general) mythological names.

With the naked eye you can see about 4000 stars in each hemisphere of the sky. There are probably several million in the most up-to-date astronomical catalogues. There are at least a billion stars in the Milky Way (our galaxy), probably quite a few billion.

There may be an infinite number of stars in the whole universe, we just don't know yet! There are at least 100 billion billion in the observable universe (this is saying that there are about 100 billion galaxies each with a billion stars, which is most likely an underestimate). This is more than any human can deal with, so the exact number doesn't matter too much. Let's just say that there are a lot of stars!


This page updated on January 28, 2019

About the Author

Karen Masters

Karen Masters

Karen was a graduate student at Cornell from 2000-2005. She went on to work as a researcher in galaxy redshift surveys at Harvard University, and is now on the Faculty at the University of Portsmouth back in her home country of the UK. Her research lately has focused on using the morphology of galaxies to give clues to their formation and evolution. She is the Project Scientist for the Galaxy Zoo project.

Twitter:  @KarenLMasters

Most Popular

Our Reddit AMAs

AMA = Ask Me (Us) Anything