There are billions of galaxies, each with at least 100 billion stars. We can’t even see most of the stars in our galaxy. There are more stars out there than there are grains of sand on all of the beaches in the entire world.
Some of the brightest stars in our Milky Way galaxy have official names, handed down from ancient astronomers. In fact, there are some that have been known by several different names over the centuries. You might have heard of some of them such as Sirius (the brightest star in our solar system after the sun), Polaris and Vega.
In addition, there are 88 constellations – 44 in each hemisphere. Named by ancient cultures by the patterns they resembled (people, animals, objects), the constellations played important roles in mythology. There is the story, for example, of the constellation Andromeda visible in the northern sky and listed by 2nd century astronomer Ptolemy. Andromeda was the beautiful princess and daughter of Queen Cassiopeia and King Cepheus, who was chained to the rock, a curse due to her mother who boasted too much of her beauty.
When assigning scientific names, the brightest star in these constellations was given the ‘alpha’ designation, beta was the next brightest, and so on. Once all of the Greek letters were assigned, the rest of the stars received numeric designations.
However most known stars are catalogued by their coordinates, abbreviations that stand for the type of star, and symbols that further describe information about the star. The American Astronomical Society uses different catalogs to identify stars. The HIPPACROS (HIP) catalog, a high-precision catalog of more than 100,000 stars, was published in 1997. Other catalogs include the lower precision Tycho catalog of more than a million stars, also published in 1997, and the enhanced Tycho-2 catalog of 2.5 million stars published in 2000.
