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What Are Some Techniques Used to Name Stars?

How did stars get their names? Many were named thousands of years ago. Stars and constellations, such as Orion and Polaris, got their names from mythology and location. These days, stars are named in a variety of ways, including type and constellation. While many star names are in Greek, Arabic and Chinese, a common method is to convert the constellation name into Latin, such as "Pegasi" for "Pegasus." Stargazers take note: Scammers will try to sucker you into buying a star name. Don't be fooled; the International Astronomical Union is the only organization with the authority to name stars.

Constellation
- One popular method for naming stars was created by German astronomer Johann Bayer. He started naming stars based on two factors: The constellations the stars were in and their degree of brightness. He created a list of star names in a catalog called "Uranometria" in 1603. He used letters in the Greek alphabet to determine how bright a star was. For example, the name Alpha Cygni was given to the brightest star in the constellation Cygnus. Once the Greek letters were used up, however, he attached a lowercase letter to the star number. For example, such a star name would be 25a or 51c.
Flamsteed Numbers
- Some stars are named with a Flamsteed number. In 1712, astronomer Edmond Halley published the unauthorized version of a catalog called "Historia Coelestis," which was created by John Flamsteed. This catalog contained a numbering method for star names. The stars were numbered in the order of their Right Ascension. The Right Ascension of a star signifies it east/west direction, similar to longitude used on earth. The opposite of the Right Ascension is Declination (or Dec), which measures a star's north/south direction.One star's Right Ascension resulted in the name RA61 Cygni, as it was located in the constellation Cygnus. Once astronomers run out of Greek letters to apply to a star name, they place a number before the constellation name, such as with 51 Pegasi.
Type and Coordinates
- Another way to name a star is to find out its coordinates. For example, one star carries the name NTTS 045251+3016. The initials "NTTS" stand for "Naked T Tauri stars." The number's 045251+3016 are the star's coordinates. Astronomers get a star's coordinates by studying digital star maps of the known universe on a computer to analyze the RA and Dec of known stars near the star without coordinates. They next use the star's RA and Dec coordinates to obtain the star's pixel coordinates of the centroid of the star. Next, they determine the pixel coordinate-to-RA and Dec transformation of the star using an astrometry calculator
Proximity to Other Stars
- A specific naming method exists for stars that are close together. First, astronomers look at how bright the stars are. The stars are given one Roman letter to designate their degree of brightness. If one star is not as bright as the other, this star will have a different letter. Next, the astronomer looks at where this star pair is located. If it's in a constellation, then they will name it after the constellation. Thus, the star pair could receive the name Sirius AA or Sirius AB.

Astronomy