Diagram caption: The constellation Aries along with its bright stars and surrounding constellations. Aries is surrounded by (going clockwise from the top) Triangulum, Pisces, Cetus, Taurus and Perseus. Aries lies on the ecliptic (shown here as a blue line), this is the path the Sun appears to take across the sky over the course of a year. The Sun is in Aries from mid April to mid May. The other planets of the Solar System can often be found in Aries.

Aries 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. Aries is most visible in the evenings in the northern hemisphere winter and southern hemisphere summer.

The y-axis of this diagram is in degrees of declination 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 labeled 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 line marking the ecliptic, 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. Credit Link

Diagram translation status: Not yet approved by a reviewer
Related glossary terms: 双鱼座 , 天球坐标 , 星座 , 白羊座 , 视星等 , 赤纬 , 赤经（RA） , 金牛座 , 黄道 , 黄道十二宫
Categories: Naked Eye Astronomy

Diagram license: Creative Commons 署名 4.0 国际 (CC BY 4.0) Creative Commons 署名 4.0 国际 (CC BY 4.0) icons