How Does a Constellation Get Its Name?
- Constellations were originally named by ancient farmers. Ancient astronomy is closely linked to ancient agriculture. These ancient civilizations noticed that certain groupings of stars resembled familiar objects or characters and would come and go with the seasons. Naming the different groupings of stars and watching their places in the sky helped early civilizations plant and harvest their crops with the changing seasons. The ancient constellations that we still have records of were named by the Greeks. Their etymology is mostly Latin and comes from Greek mythology and the signs of the zodiac.
- Today the International Astronomical Union (IAU), a collection of scientists and astronomical associations from many different countries, is the officially recognized naming organization of celestial bodies, including constellations. The names of constellations have been fixed since the 1930s, and no more can be named. There are for-profit companies that promise to name stars for buyers, but the IAU does not recognize the claims of these companies. The name of star a person purchases from a star-naming company are entered into a star registry, but this registry is not officially recognized by the IAU.
- Many well-recognized, so-called constellations, such as the Big Dipper in the skies of the Northern Hemisphere, aren't constellations at all, according to the IAU. The Big Dipper is officially known as an asterism: a familiar shape of stars in the night sky that humans have traditionally used to orient themselves. The Southern Cross in the southern hemisphere, on the the other hand, is considered a constellation. Why? It has to do with the closeness of the stars in space, not just from our vantage point on Earth. The stars of the Big Dipper vary greatly in astronomical distance and only seem to be closer together from our vantage point, while the stars of the Southern Cross are close enough together in space to still be seen in the shape of a cross from outside the solar system. The IAU has fixed the number of constellations at 88, basically dividing the sky as seen from Earth into so many pieces of sky. So if you're looking to have a new constellation named for your new wife, she will just have to settle for an asterism instead, according to the IAU.