Alvan Graham Clark, a well-known telescope-maker and amateur astronomer in Cambridgeport, Massachusetts, was testing a new unprecedented 18½ inch lense he had ground originally for the University of Mississippi when he discovered a new star. Sirius, the brightest in the sky, known also as the Dog Star, had been rumored to have a smaller "companion star" for some time. Clark observed that this was indeed the case. Known as "Sirius B," it was also the first observed "white dwarf" star. (By John Osborne)