A constellation is a picture in the sky. Many of these familiar patterns of stars come to us from prehistoric times when humans first looked up into the night sky and tried to make sense of it. Today, the International Astronomical Union is the sole authority for assigning designations and names to celestial bodies, and they have divided up the sky into 88 sections. These sections are irregular in shape and size as the IAU has tried to maintain ancient constellation boundaries as much as possible.
The online charts are drawn in colour on a dark background. Coloured circles of varying radius are used to represent stars. The larger the circle, the brighter the star. Binary and multiple star systems that appear as a single object to the naked eye are represented by their combined magnitude. The colours represent the spectral types (surface temperatures) of the stars, with blue being the hottest and red the coolest.
A selection of other interesting naked-eye objects are drawn in green. Galaxies are represented by ellipses, nebulae are triangles, open clusters are squares, globular clusters are circles and other objects of interest are denoted with a spiked circle. The positions of meteor shower radiants are shown with five splayed lines. The thick green lines represent the outlines of the constellations.
Star positions (epoch 2000), magnitudes and colours are taken from the Bright Star Catalogue, Fifth Revised Edition. The limiting stellar magnitude is +6.5 but there is no limiting magnitude for other objects.
|Apus||Coma Berenices||Leo Minor||Pyxis|
|Canis Minor||Fornax||Ophiuchus||Triangulum Australe|