Diagram caption: The zodiac constellation Cancer and its surrounding constellations. Starting from the top of the diagram and going clockwise, these are Lynx, Gemini, Canis Minor, Hydra, Leo and Leo Minor. The ecliptic (shown here as a blue line) passes almost exactly through the middle of the constellation, this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Cancer from late July to mid August. The other planets of the Solar System can often be found in Cancer.

Cancer lies just north of the celestial equator and is thus visible at some time in the year from all of planet Earth except for the most antarctic regions of the world. Cancer is most visible in the evenings in the northern hemisphere spring and southern hemisphere autumn.

Two star clusters are visible in Cancer: M44, an open cluster often called the Beehive Cluster, and M46, a denser open cluster with about four times more stars than M44. These clusters are indicated by yellow circles with a dotted border on the map.

The y-axis of this diagram is in degrees of declination and with north as up and the x-axis is in hours of right ascension with east to the left. The sizes of the stars marked here relate to the star's apparent magnitude, a measure of its apparent brightness. The larger dots represent brighter stars. The Greek letters mark the brightest stars in the constellation. These are ranked by brightness with the brightest star being labelled alpha, the second brightest beta, etc., although this ordering is not always followed exactly. The dotted boundary lines mark the IAU's boundaries of the constellations and the solid green lines mark one of the common forms used to represent the figures of the constellations. Neither the constellation boundaries nor the lines joining the stars appear on the sky.

Diagram credit: Adapted by the IAU Office of Astronomy for Education from the original by IAU/Sky & Telescope. Link per i Crediti

Stato di traduzione del Diagramma: Non ancora approvato da un revisore
Termini di glossario connessi: Ammasso aperto , Cancro , Coordinate celesti , Costellazione , Eclittica , Gemelli , Leone

Diagram license: Creative Commons Attribuzione 4.0 Internazionale (CC BY 4.0) Creative Commons Attribuzione 4.0 Internazionale (CC BY 4.0) icone