Hercules is a constellation named after Hercules, the Roman mythological hero adapted from the Greek hero Heracles. Hercules was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations defined by the International Astronomical Union. It is the fifth largest of the modern constellations. Corona Borealis is a small constellation in the northern sky. Its name is Latin for northern crown, a name inspired by its shape; its main stars form a semicircular arc. Lyra is a small constellation. Its principal star, Vega, a corner of the Summer Triangle, is one of the brightest stars in the sky. A Celestial Atlas (1822) by Alexander Jamieson, inspired by the star atlas of Johann Elert Bode, but restricted itself to stars that could be seen with the naked eye. Comprising a systematic display of the heavens in a series of thirty maps illustrated by scientific description of their contents and accompanied by catalogues of the stars and astronomical exercises, plate 8, 1822.