Friday, July 10, 2009

July 10: Alvan Graham Clark

Alvan Graham Clark
July 10, 1832 – June 9, 1897

Alvan Graham Clark was an American astronomer and telescope-maker. He was the son of Alvan Clark, founder of Alvan Clark & Sons.

Alvan Clark & Sons was an American maker of optics that became famous for crafting lenses for some of the largest refracting telescopes of the nineteenth and early twentieth centuries. Founded in 1846 in Cambridgeport, Massachusetts by Alvan Clark (1804–1887), a descendant of Cape Cod whalers who started as a portrait painter, and his sons George Bassett Clark (1827–1891) and Alvan Graham Clark. Five times, the firm built the largest refracting telescopes in the world.

On January 31, 1862, while testing a new 18 1/2 inch refracting telescope, he made the first observation of Sirius B in Cambridgeport, Massachusetts. The magnitude 8 companion of Sirius is also the first known white dwarf star.

The 18 1/2 inch refracting telescope is now still being used at the landmark Dearborn Observatory of Northwestern University in Evanston, IL.

For many years the Dearborn Telescope, the largest telescope in the world in its time, has been one of the most popular exhibits at the Adler Planetarium. The telescope has had an unusually varied career, and was recently sent out for a careful, professional facelift before resuming its place in the New Adler.

1 comment:

  1. Hello Sir

    Your blog is very much interesting; I am your blog favorites. I follow your blog.

    I have been maintaining this blog for more than a year.

    My blog deals with current news on NASA Space Missions,International Space News,Shuttle & Station,Moon & Mars,Solar System,Earth,Universe, Aeronautics,Science & Technology

    I have got many back links for my blog from government sites, org sites, as well as edu sites.

    Sites are as follows

    So If you could provide me a link to my blog, it will be much more useful for user and young school and college peoples.

    Around 10,0000 visitors daily visits my blog. So it will be highly benefited for your sites also.

    It would be great pleasure if you can add this link in your blog so that it can benefit our visitors.

    Hope you would add my blog.

    Please respond to me for this mail.

    Awaiting for your reply.

    Jeff Adams