Constellation, Crab
Cancer
The crab that nipped Heracles in his fight with the Hydra. Faint itself, it holds the Beehive Cluster, a misty patch the ancients saw as a manger with two donkeys.
From New York on October 13, 2026, the centre of Cancer rises at 12:56 AM, is highest at 8:02 AM (67° above the horizon in the S) and sets at 3:12 PM.
In the 3D sky
The sky over New York turned towards Cancer. Drag to look around.
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Evening visibility over the year
Height of the constellation’s centre above the horizon at 10 pm local time on the 15th of each month, from New York. Above about 30° it is well placed.
Name and history
In Greek myth, Heracles was fighting the many-headed Hydra in the swamp near Lerna when a crab came out of the water and bit his foot. He stamped on it and crushed it. The goddess Hera, who hated Heracles, rewarded the crab by placing it among the stars of the zodiac. Its Greek name was Karkinos, Carcinus in Latin. Fittingly for such a minor character, it is the faintest of the zodiac figures.
At its heart lies the Beehive Cluster, also called Praesepe, the manger. Greek writers saw two nearby stars, the Northern and Southern Asses, feeding from it. In a story told by Eratosthenes, Dionysus, Hephaestus and their companions rode donkeys into the battle between the gods and the Giants, and the braying put the Giants to flight. Galileo first saw in 1609 that the Manger is a cluster of stars. In the time of the ancient Greeks the Sun stood in Cancer at the June solstice, which gave the Tropic of Cancer its name.
Sources: Ian Ridpath, Star Tales: Cancer
Brightest stars
| Star | Designation | Magnitude | Distance |
|---|---|---|---|
| Tarf | β Cnc | 3.53 | 303 light-years |
| Asellus Australis | δ Cnc | 3.94 | 131 light-years |
| Yuyu | ι Cnc | 4.03 | 331 light-years |
| Acubens | α Cnc | 4.26 | 188 light-years |
| Asellus Borealis | γ Cnc | 4.66 | 181 light-years |
| Tegmine | ζ2 Cnc | 4.67 | 82 light-years |
Facts
| Area | about 506 square degrees (31 of 88) |
|---|---|
| IAU abbreviation | Cnc |
| Sky | Northern sky |
| Origin | Listed in Ptolemy’s Almagest, about AD 150, as Karkinos |
| Stars brighter than magnitude 5 | 6 |
| Centre (J2000) | 8.6 h, 18° |
Deep-sky objects
Galaxies, clusters and nebulae brighter than magnitude 9, from the OpenNGC catalogue. Most need binoculars or a telescope and a dark sky.
Boundaries: International Astronomical Union, via Astronomy Engine. Areas are computed from the boundaries by sampling (within about one percent). Names and lines: Stellarium. Stars: HYG Database. Deep-sky objects: OpenNGC. Calculated with Astronomy Engine, an open-source library verified against the US Naval Observatory and NASA JPL. Data sources
How to use this page
Choose your place and a night at the top. The answer and the 3D view show where the constellation is, when it is highest and whether it rises at all from where you are. The chart shows its stars and lines, and the tables list its brightest stars and the deep-sky objects inside it.
Frequently asked questions
When is a constellation best seen?
When it is highest in a dark sky, which the page gives for the night you pick. Each constellation is best placed in a particular season, because the stars rise about four minutes earlier every night.
Why can I not see a constellation from my place?
Constellations far south of the celestial equator never rise from northern places, and those far north never rise from southern ones. The page says when this is the case.
What are the constellation boundaries?
The International Astronomical Union divides the sky into 88 areas with official boundaries. The stick figures are only a drawing aid, the boundaries say which constellation a point in the sky belongs to.
Related guides
- How to learn the constellationsStart with one bright pattern you cannot miss, use it as a signpost to its neighbours, and come back a month later: the sky will have turned, and you will know a little more of it.
- Altitude and azimuth: finding things in the skyTwo angles tell you exactly where to look: which direction, and how high.
- Light pollution and dark skies: the Bortle scaleFrom a city centre you can count a few dozen stars. From a truly dark site you can count a few thousand, with the Milky Way bright enough to cast a shadow. The Bortle scale puts a number on the difference.
- Binoculars for stargazing: what to buy and what to look atA pair of 7x50 or 10x50 binoculars shows the craters of the Moon, the moons of Jupiter, dozens of star clusters and the Andromeda Galaxy, for a fraction of the cost of a telescope.