Variable stars are named by the constellation they are found in, and the order in which they are discovered.
The first variable star discovered in a constellation is given the letter R, followed by the constellation's
Genitive. For example, R Orionis. The genitives are usually shortened to their
3-letter abbreviation (e.g. "R Ori"). After R, the next variable star to be discovered in Orion would be S
Ori, then T Ori, and so forth, down to Z. After Z, the sequence starts again with double letters: RR, RS, RT,
etc., down to ZZ. Then it starts over with AA. Once QQ is reached, the variable stars are given the letter V,
followed by a number, for example "V402 Cephei" (or V402 Cep).
This naming system can sometimes produce some interesting names. For example, the fourth variable star
discovered in Gemini is "U Gem", while the fourth in Ophiuchus is "U Oph". A friend of mine always
referred to the star he was researching in Lynx as a "she", because its name was "AN Lyn".
