Massachusetts astronomer Alvan Clark discovers the new star now called "Sirius B"

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)
Source Citation
The American Annual Cyclopedia and Register of Important Events of the Year 1862 ... (New York: D. Appleton & Co., 1869), II: 176. 
    Date Certainty
    Exact
    Type
    Science/Technology
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