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The Cup

Constellation of the southern sky

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Constellation FamilyHercules
Celestial QuadrantSQ3, extending slightly into SQ2
Right Ascension10h52 to 11h58
Declination-25.3° to -6.8°
Area (sq deg)282
Brightest StarDelta Crateris
Optimum VisibilityMarch / April
NotesThis small constellation is home to several stars around which orbiting planets have been confirmed. It contains a number of galaxies, of which one, designated Crater 2, is a relatively close dwarf galaxy that is satellite of the Milky Way.
Map of Crater Map of Crater


Crater is a very ancient constellation: this region of the sky was known as 'The Cup' at least as long ago as the second century, and the name is almost certainly older.

According to myth, the god Apollo sent a crow (represented by Corvus, the neighbouring constellation) to fetch the Water of Life in a Cup. Tempted by figs, the crow forgot its errand and dropped the cup, returning with a water-snake (Hydra) in its claws. The infuriated deity banished all three, crow, cup and water-snake, to the sky.


The stars of Crater are unremarkable except in one respect; their unusual uniformity. Most lie between 100 and 200 light years from the Sun, are between fourth and fifth magnitude, and belong to the K-type orange spectral classification.

The Alpha star is known as Alkes, but at a faint magnitude of just over four, this is not in fact the brightest of the group. In fact, though, it is an orange giant, and would be considerably more noticeable if it were closer than its actual distance of 174 light years.

Marginally brighter than Alkes is Delta Crateris, a yellow-orange giant that lies slightly farther from the Solar System, but is intrinsically rather more luminous than the Alpha star.


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