Edwin Powell Hubble ( born November 20, 1889 in Marshfield, Missouri, † September 28, 1953 in San Marino, California ) was an American astronomer. He discovered the nature of the spiral nebulae and the Hubble constant of the galactic cosmology and is the namesake of the Hubble Space Telescope.
Life and work
Hubble studied physics and astronomy at Chicago and finished it in 1910, graduating with a Bachelor of Science degree. He then left the U.S. to study law at Oxford, where he graduated as master and returned to the U.S. after three years.
When it Vesto 1912 Slipher at the Lowell Observatory in Flagstaff ( Arizona) succeeded for the first time to measure the radial velocity of a spiral nebula, Hubble also as a student with the relative velocity of the Andromeda nebula (M31 ) was involved in the Milky Way system. At Mount Wilson Observatory, he was able to prove in 1923 that M31 lies far beyond our galaxy. The results of his observations and calculations, Cepheids in Spiral Nebulae, he laid at the turn of 1924/25, before the annual meeting of the American Association astronomers AAS on which they were promulgated on 1 January 1925.
Due to the spatial distribution of galaxies, and their inter alia, in the spectrum Milton Humason proven redshift, the Belgian priest Georges Lemaître postulated in June 1927, the expansion of the universe in accordance with Einstein's general theory of relativity. Hubble published two years later, 1929, with additional data the same linear relationship between the redshift and the distribution of extragalactic nebula, but did not draw the conclusion of a physical expansion of the universe at this time. However, in the public perception this discovery Lemaître is often attributed to Hubble.
Hubble and Humason discovered on the basis of work Slipher that the spectra of different galaxies are not shifted about equally to the Red and Blue, but that there are significantly more red-shifted spectra. If one interprets the frequency shift as a Doppler effect, so it can be deduced that remove almost all of the observed galaxies from us. Hubble was the first to set a direct proportional relationship between redshift and distance of galaxies, which would mean that this distant island universes move more quickly away from us, the farther away they are. Hubble himself used the term ' apparent velocity ', as he was restrained in the physical interpretation of the observations.
The quantity which describes this expansion, in honor of him called the Hubble constant H. She is on the current measurement by WMAP in 2003, 71 ± 4 km / s per megaparsecs (1 Megaparsec ~ 3.26 million light years), which corresponds to an age of space from 13 to 14.5 billion years ago. In recent decades have been specified for H values between 50 and 100 km / s / Mpc and could only be determined by space observatories relatively accurate.
Hubble has also developed the Hubble sequence is a morphological classification scheme for galaxies. On 30 August 1935, he discovered the asteroid Cincinnati.
On September 28, 1953 Hubble died at 63 years, while at the Palomar Observatory preparations met for several observing nights, of a stroke.
In 1935, the Barnard Medal he was awarded. In 1940 he was awarded the Gold Medal of the Royal Astronomical Society.
The Hubble Space Telescope (HST ) was also named after him. Through undisturbed by the Earth's atmosphere observation possibilities its CCD sensors can record the finest details of the planets and star systems.
The lunar crater Hubble and the asteroid ( 2069 ) Hubble are named after him.