Ian Ridpath is an internationally renowned writer and editor. His works include the Oxford Dictionary of Astronomy and popular series of night sky guides for beginners, including The Collins Stars and Planets Guide and Collins Gem Stars. Ian is the recipient of the Astronomical Society of the Pacific's Klumpke-Roberts Award for outstanding contributions to the public understanding and appreciation of astronomy. Ian is based in London, UK.

Wil Tirion was trained in graphic arts and always had an interest in astronomy and especially star charts. In 1983 he became a self-employed Uranographer, a specialist in drawing charts of the night sky. Since then he has contributed to many books including the bestselling Collins Guide to the Night Sky annual. In 1987 he received the 'Dr. J. van der Bilt-prize', a Dutch award for amateur astronomers. In 1993 he had a minor planet named after him: (4648) Tirion = 1931 UE.