Alvan Graham Clark

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Alvan Graham Clark
Sirius B
Scientific career
FieldsAstronomy
Signature

Alvan Graham Clark (July 10, 1832 – June 9, 1897) was an American astronomer and telescope-maker.

Biography

Alvan Graham Clark was born in Fall River, Massachusetts, the son of Alvan Clark, founder of Alvan Clark & Sons.[1]

On January 31, 1862, while testing a new 18.5-inch (470 mm) aperture

Friedrich Wilhelm Bessel in 1844) that Sirius, the brightest star in the night sky with an apparent magnitude
of −1.46, had an unseen companion disturbing its motion. Clark used the largest refracting telescope lens in existence at the time, and the largest telescope in the United States, to observe the magnitude 8 companion.

Clark's 18.5 inch refracting telescope was then delivered to his customer, the landmark Dearborn Observatory of Northwestern University in Evanston, Illinois, where it is still being used today.[2]

Alvan Graham Clark died in Cambridge, Massachusetts on June 9, 1897.[3]

See also

References

  1. ^ The National Cyclopaedia of American Biography. Vol. V. James T. White & Company. 1907. p. 386. Retrieved April 2, 2021 – via Google Books.
  2. ^ Dearborn Observatory: History
  3. ^ "Deaths". The Boston Globe. June 10, 1897. p. 10. Retrieved April 2, 2021 – via Newspapers.com.

External links