When Corvus , Apollo's crow, refused to go for water to ease his thirst, Apollo placed the cup of water just in front of him where he could see it but never drink from it, though he chase it endlessly. The size of each star indicates its relative magnitude . Constellation names are light blue . Messier object numbers are pink . Globular clusters are gold starbursts .
Open clusters are dotted white circles.
Planetary nebula are green diamonds . Bright nebula are magenta squares . Dark nebula are grey rectangles . Green x's are x-ray sources. Purple O's with a diagonal slash through them are quasars.