The constellation Draco, 1603.
© Science Museum / Science & Society Picture Library
Illustration taken from 'Uranometria' (1603) by Johann Bayer, showing Draco (the Dragon), a constellation near to the celestial north pole. German astronomer and lawyer Johann Bayer (1572-1625) invented the system for naming stars using letters from the Greek alphabet, a system still used today for the brighter stars - those visible to the human eye without the aid of a telescope. 'Uranometria' depicts the positions of nearly 1000 stars in addition to those identified by Tycho Brahe. The main object of interest to astronomers in Draco is the Cat's Eye Nebula, a planetary nebula. Planetary nebulae are formed when a dying star is unable to sustain fusion reactions at its core and throws off its outer material into space. The star then collapses, becoming a white dwarf.