Dearborn Observatory

Dearborn Observatory stands on the lakeside campus of Northwestern University in Evanston, Illinois, home to one of the most historically significant telescopes in American astronomy.

About Dearborn Observatory

The current Dearborn Observatory building was constructed between 1888 and 1889, and Northwestern University has operated it since the observatory relocated to the Evanston campus in 1889. Its predecessor building, completed in 1865, stood on the campus of the old University of Chicago before the instrument and name moved on. The observatory sits at an elevation of 195 metres.

History

The observatory's centrepiece is an 18.5-inch (469.9 mm) refracting telescope built in 1861 by Alvan Clark & Sons, which was the largest telescope in the United States in the late 1860s. On January 31, 1862, while testing the new lens, Alvan Graham Clark used it to discover Sirius B, the faint white dwarf companion to Sirius, the brightest star in the night sky. In 1939 the entire building was relocated roughly 200 metres to make way for Northwestern's Technological Institute, and an aluminum dome was added in 1997.

Telescopes & research

The historic 18.5-inch Clark refractor remains the observatory's primary instrument today, still used for public viewing more than 160 years after its Sirius B discovery.

Location & getting there

Dearborn Observatory is located on Northwestern University's Evanston campus, on the shore of Lake Michigan just north of Chicago.

Visiting Dearborn Observatory

Northwestern University hosts free public viewing nights at the observatory on Fridays, 9-11 PM (8-10 PM in winter). Check the university's observatory page for schedule changes, especially around weather and university holidays.

See your named star from here

Standing where Sirius B was first spotted through a telescope, it's easy to feel the pull of naming a star of your own. Name a star with Star Register and bring its coordinates to a Dearborn Observatory viewing night, or browse the star catalogue to see stars already claimed near Illinois.