Herschel was looking at individual stars and trying to see if they were double stars. A double star is where you have two stars that may appear to be close together, but they are actually far apart. He found some of the er double stars were not obeying what could be explained by parallax. They seemed to have slightly different positions. And he discovered binary stars - a system with two objects relatively close to each other which interact gravitationally almost in the same way as a planet goes round the sun. Do you want to take that up? Monica?
Melvyn Bragg and guests discuss William Herschel (1738 – 1822) and his sister Caroline Herschel (1750 – 1848) who were born in Hanover and made their reputation in Britain. William was one of the most eminent astronomers in British history. Although he started life as a musician, as a young man he became interested in studying the night sky. With an extraordinary talent, he constructed telescopes that were able to see further and more clearly than any others at the time. He is most celebrated today for discovering the planet Uranus and detecting what came to be known as infrared radiation. Caroline also became a distinguished astronomer, discovering several comets and collaborating with her brother.
With
Monica Grady
Professor of Planetary and Space Sciences at the Open University
Carolin Crawford
Institute of Astronomy, Cambridge and an Emeritus Fellow of Emmanuel College, University of Cambridge
And
Jim Bennett
Keeper Emeritus at the Science Museum in London.
Studio producer: John Goudie