[Pic]

Abbreviation:

Cnc

English name:

Crab

Coordinates

see Stellar data

IV. sign of zodiac

Particulars:

• Double star iota Cnc
• Triple star system zeta Cnc
• Open star clusters M 44, M67
• Meteor Shower: Delta Cancrids

General:

The sun passes this constellation from late July to early August. In former times the Sun used to lie in this constellation when it reaches the its point farthest north - the time of the summer solstice. Nowadays the sun lies in the neighbouring constellation Gemini on the time of the summer solstice (due to the effect of precession).
Although Cancer belongs to the Zodiacal Family it is associated with the Hercules constellation family.

Stars and other objects

An attractive yet unusal triple for small telescopes is zeta Cnc. Two of the stars form a binary, consisting of two yellow stars of 5th mag and 6th mag. These two revolve each other with a peroid of 60.1 years.
Also good viewable with small telescopes is iota Cnc, a 4th mag yellow giant with a 7th mag green companion.
The open star cluster M44, also called Praesepe or Beehive Cluster, is a swarm of stars of 6th mag and fainter. Without optical help is appears as a misty patch. Because it considerably large its best viewed with binoculars.
The second Messier object in this constellation, M67 requires larger telescopes. For more information about these two open clusters please follow the links to the Messier database.
The meteor shower Delta Cancrids shows a long duration, ranging from december 14th to february 14th, which is typical for ecliptic streams. The maximum occurs between january 13th and january 17th. Detailed information about the Delta Cancrids can be found in the meteor shower database from Gary Kronk.

Mythological Background:

It is thought that this constellation represents the crab which is attacking Hercules during his fight with the water snake, Hydra.