BOND , GEORGE PHILLIPS

George Bond spent most of his early life assisting his fatherWilliam Bond , whom he succeeded as director of the Harvard College Observatory in 1859. He thereafter contributed to most of his father's observational and photographic work, including their joint discovery of Hyperion in 1848, the first photograph of a star (Vega) in 1850, and the detection in 1850 of Saturn's third ring, the so-called ‘crepe ring’. He is best known, however, for showing how stellar magnitude could be calculated from photographs. In 1857 he noted that the size of the image is relative to the brightness of the star and the length of the exposure. It is this basic fact that has been used by the compilers of the Astrographic Catalog to record measurements of stellar magnitudes. He was also the first to photograph a double star, Mizar, in 1857.