Crater (constellation)

Crater is a small constellation in the southern celestial hemisphere. Its name is the latinization of the Greek krater, a type of cup used to water down wine. One of the 48 constellations listed by the second-century astronomer Ptolemy, it depicts a cup that has been associated with the god Apollo and is perched on the back of Hydra the water snake. There is no star brighter than third magnitude in the constellation. Its two brightest stars, Delta Crateris of magnitude 3.56 and Alpha Crateris of magnitude 4.07, are ageing orange giant stars that are cooler and larger than the Sun. Beta Crateris is a binary star system composed of a white giant star and a white dwarf. Seven star systems have been found to host planets. A few notable galaxies, including Crater 2 and NGC 3981, and a famous quasar lie within the borders of the constellation. In the Babylonian star catalogues dating from at least 1100 BC, the stars of Crater were possibly incorporated with those of the crow Corvus in the Babylonian Raven (MUL.UGA.MUSHEN). British scientist John H. Rogers observed that the adjoining constellation Hydra signified Ningishzida, the god of the underworld in the Babylonian compendium MUL.APIN. He proposed that Corvus and Crater (along with the water snake Hydra) were death symbols and marked the gate to the underworld. Corvus and Crater also featured in the iconography of Mithraism, which is thought to have been of middle-eastern origin before spreading into Ancient Greece and Rome. Crater is identified with a story from Greek mythology in which a crow or raven serves Apollo, and is sent to fetch water, but it delays its journey as it finds some figs and waits for them to ripen before eating them. Finally, it retrieves the water in a cup and takes back a water snake, blaming it for drinking the water. According to the myth, Apollo saw through the fraud, and angrily cast the crow, cup, and snake into the sky. The three constellations were arranged in such a way that the crow was prevented from drinking from the cup, and hence seen as a warning against sinning against the gods.