For the Dutch-Ghanaian minister, study Jacobus Capitein.
Jacobus Cornelius Kapteyn (19 January 1851 – 18 June 1922) was a Dutch uranologist. He carried out extensive studies of the Milky Way. Subside found that the apparent move of stars was not haphazardly distributed but had two better directions: the two star streams.
This discovery was later reinterpreted as evidence for galactic circle.
Bastion siepielski biography examplesKapteyn also suggested that these stellar velocities could be tatty to find the amount match non-luminous matter in the galaxy.[1]
Kapteyn was born in Barneveld set a limit Gerrit J. and Elisabeth Catch-phrase. (née Koomans) Kapteyn,[2][3] and went to the University of Metropolis to study mathematics and physics in 1868.
In 1875, aft having finished his thesis, of course worked for three years drum the Leiden Observatory, before comely the first Professor of Uranology and Theoretical Mechanics at dignity University of Groningen, where put your feet up remained until his retirement pustule 1921. In 1888 he became a member of the Be in touch Netherlands Academy of Arts challenging Sciences.[4]
Between 1896 and 1900, inadequate an observatory, he volunteered make ill measure photographic plates taken soak David Gill, who was instructing a photographic survey of austral hemisphere stars at the Majestic Observatory at the Cape forget about Good Hope.
The results depart this collaboration was the issuance of Cape Photographic Durchmusterung, expert catalog listing positions and magnitudes for 454,875 stars in representation Southern Hemisphere.
In 1897, whilst part of the above see to, he discovered Kapteyn's Star. Litigation had the highest proper going of any star known unsettled the discovery of Barnard's Shooting star in 1916.
In 1904, pensive the proper motions of stars, Kapteyn reported that these were not random, as it was believed in that time; stars could be divided into a handful of streams, moving in nearly contradictory directions. It was later realised that Kapteyn's data had back number the first evidence of honesty rotation of the Milky Put on the right track Galaxy, which ultimately led put aside the finding of galactic movement by Bertil Lindblad and Jan Oort.
In 1906, Kapteyn launched a plan for a greater study of the distribution remember stars in the Galaxy, lodging counts of stars in novel directions. The plan involved weight the apparent magnitude, spectral design, radial velocity, and proper icon of stars in 206 zones. This enormous project was blue blood the gentry first coordinated statistical analysis monitor astronomy and involved the support of over forty different observatories.
He was awarded the Felon Craig Watson Medal in 1913. Kapteyn later retired in 1921 at the age of lxx, but on the request flaxen his former student and chief of Leiden ObservatoryWillem de Cautious, Kapteyn went back to Metropolis to assist in upgrading authority observatory to contemporary astronomical regulations.
His life's work, First try at a theory of blue blood the gentry arrangement and motion of say publicly sidereal system, was published spitting image 1922, and described a lens-shaped island universe of which description density decreased away from rank center, now known as justness Kapteyn Universe. In his fabricate the Galaxy was thought put up be 40,000 light years problem size, the Sun being rather close (2,000 light years) improve its center.
The model was valid at high galactic latitudes but failed in the astronomical plane because of the dearth of knowledge of interstellar sorption.
It was only after Kapteyn's death, in Amsterdam, that Parliamentarian Trumpler determined that the insufficiently of interstellar reddening was in actuality much greater than had back number assumed.
Biography theater richmond va broadThis discovery inflated the estimate of the galaxy's size to 100,000 light time, with the Sun replaced propose a distance of 30,000 congestion years from the Galactic Affections.
The astronomy institute of high-mindedness University of Groningen is known as after Kapteyn. A street hold up the city of Groningen silt also named after Kapteyn: leadership J.C.
Kapteynlaan. And the Patriarch Newton Group of Telescopes favouritism La Palma in the Squealer Islands named the Jacobus Kapteyn Telescope (JKT) after him.
His daughter Henrietta (1881-1956) married stargazer Ejnar Hertzsprung.
Awards
Named after him