Friedrich Wilhelm August Argelander (March 22 1799 – February 17 1875) was a Prussian astronomer.

He born in Memel in the Kingdom of Prussia (now Klaipeda in Lithuania), the son of a german father and finnish mother. He studied with Freidrich Bessel, and obtained his Ph.D. in 1822 at Königsberg.

From 1822 until 1836 he was the head of the Finnish observatory at Turku then at Helsinki. He then moved to Bonn, Germany. Here he developed a friendship with King Frederick William IV, who funded a new observatory at Bonn. There he became known for his work in recording the positions of stars.

Together with Adalbert Krüger and Eduard Schönfeld, he was responsible for the star catalogue known as the Bonner Durchmusterung, published between 1852 and 1859, which gave the positions and brightness of more than 324,000 stars, although it did not cover much of the southern half of the sky. This was the last star map to be published without the use of photography.

Argelander was the first astronomer to begin careful study of variable stars. Only a handful were known when he began, and he was responsible for introducing the modern system of identifying them. He also made a rough determination of the direction in which the Sun was moving.

In 1863 he founded an international organization of astronomers named the Astronomische Gesellschaft. He also won the Gold Medal of the Royal Astronomical Society the same year.

The Argelander crater on the Moon is named for him.

References

• Asimov's Biographical Encyclopedia of Science and Technology, Isaac Asimov, Doubleday & Co., Inc., 1972, ISBN 0385177712. (Parts of this page are based on this biography.)

External links

Obituaries

• MNRAS 36 (1876) 151