It was added by Julius Ceaser at the time of the establishment of the Julian calandar. Description Libra is the only inanimate object in the zodiac. 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.