The name, the story, the myth
Although it is one of the darkest constellations in the whole sky, the constellation of the Cup, also known as Crater, is very old dating back to Ptolemy's time.
Mythologically, the cup is the object with which the raven (represented by the constellation Crow) had to collect the pure water of life on behalf of Apollo, determined to make a sacrifice in honour of Zeus.
Since the bird stopped to eat figs and was late, Apollo sent it to heaven with the cup.
In Roman mythology, besides Apollo, the cup was also attributed to Bacchus, and Hercules, but also to the Greek hero Achilles and many others.
Observation
The Cup is a spring constellation, which passes in meridian between the end of February and the beginning of March and can be found under the Virgin and the Lion, very low on the horizon.
Heavenly bodies
The constellation is composed by very weak little stars: the alpha star has a magnitude of 4,2 and is of yellow-orange colour, it is called Alkes, that means "the basin" or "the cup of the wine" and it was the Arabic name for the whole constellation; the brightest star, Delta, has a magnitude equal to 3,6.
Non-stellar objects are not relevant at all.