Alvan Graham Clark born in Fall River

Fall River, Massachusetts

Fall River is a city in Bristol County, Massachusetts, in the United States. It is located about south of Boston, southeast of Providence, Rhode Island, and west of New Bedford and south of Taunton. The city's population was 88,857 during the 2010 census, making it the tenth largest city in...

, Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

, was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 astronomer

Astronomy

Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...

 and telescope

Telescope

A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

-maker. He was the son of Alvan Clark

Alvan Clark

Alvan Clark , born in Ashfield, Massachusetts, the descendant of a Cape Cod whaling family of English ancestry, was an American astronomer and telescope maker. He was a portrait painter and engraver , and at the age of 40 became involved in telescope making...

, founder of Alvan Clark & Sons

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 19th and early 20th centuries...

.

On January 31, 1862, while testing a new 18½ inch refracting telescope

Telescope

A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...

, he made the first observation of Sirius B in Cambridgeport

Cambridgeport

Cambridgeport is one of the neighborhoods of Cambridge, Massachusetts. It is bounded by Massachusetts Avenue, the Charles River, the Grand Junction Railroad, and River Street. The neighborhood contains predominantly residential homes, many of the triple decker style common in New England...

, Massachusetts

Massachusetts

The Commonwealth of Massachusetts is a state in the New England region of the northeastern United States of America. It is bordered by Rhode Island and Connecticut to the south, New York to the west, and Vermont and New Hampshire to the north; at its east lies the Atlantic Ocean. As of the 2010...

. The magnitude 8 companion of Sirius is also the first known white dwarf

White dwarf

A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...

 star.

The 18½ inch refracting telescope is now still being used at the landmark Dearborn Observatory

Dearborn Observatory

The Dearborn Observatory is an astronomical observatory located on the Evanston campus of Northwestern University. The observatory was originally constructed in 1888...

 of Northwestern University

Northwestern University

Northwestern University is a private research university in Evanston and Chicago, Illinois, USA. Northwestern has eleven undergraduate, graduate, and professional schools offering 124 undergraduate degrees and 145 graduate and professional degrees....

 in Evanston

Evanston

Evanston may refer to locations:in Australia:* Evanston, South Australiain Canada:* Evanston, Calgary, a neighbourhood in Calgary, Alberta* Evanston, Nova Scotiain the United States:...

, IL.