James Edward Keeler
James Edward Keeler ( born September 10, 1857 in La Salle, Illinois ( USA), † August 12 1900 in San Francisco) was an American astrophysicist. It dealt V.A. to with planetary observation and spectroscopy.
Life
Between his twelfth and twentieth year Keeler did not go to school, but continued his education independently. Keeler studied since 1877 with the help of a patron at Johns Hopkins University in Baltimore, where he made his degree in 1881. He became an assistant to Samuel Pierpoint Langley at the Alleghenny Observatory in Pennsylvania. Here he remained until 1886. Began his work at the observatory with an expedition to the Rocky Mountains, to measure the infrared radiation from the sun.
Between 1883 and 1884 he held on to further studies in Heidelberg and Berlin.
1886 Keeler went to the Lick Observatory on Mount Hamilton (which, however, was not completed until 1888), where he held the position of an astronomer since 1888. On 1 June 1891 he was appointed director of the Alleghenny Observatory and at the same time employed as a professor of astrophysics at the Western University of Pennsylvania. In 1898, he returned as director back at the Lick Observatory.
James Edward Keeler died unexpectedly on August 12, 1900 in San Francisco.
Work
Keeler's specialty was spectroscopy.
His earliest work concerned the spectroscopic similarity between the spectra of stars and the Orion Nebula. 1894, the spectroscopic detection of radial velocity he succeeded planetary nebula based on the red or blue shift. Its success is largely due to its instrumental equipment; him stood a Gitterspektroskop available, which he combined with the 91cm refractor of the Lick Observatory. (see Gudrun Wolf Schmidt, Milky Way, nebula, galaxies, 1995)
He pointed out also planetary observations, such as that of Mars, where he could not confirm the observations of the so-called canals of Mars, who believed to have Schiaparelli found and the end of the 19th century provoked much speculation. In 1895 he examined the rings of Saturn with the aid of spectroscopic methods to determine their orbital period. He found that the rings do not uniformly rotated and therefore could not consist of solid matter. He supported the adoption of James Clerk Maxwell, that the rings of meteorites and dust existed. In addition, he was the first to observe the sink - hole of the Saturn rings in January, 1888.
Keeler was next to his observation Art also able to design and improve instruments. So he built an improved spectrograph, which allowed the photographic record of stellar spectral lines and low brightness.
Keeler realized that most of the galaxies have a spiral shape.