Francis Gladheim Pease
Encyclopedia
Francis Gladheim Pease was an American
astronomer
.
He joined the Yerkes Observatory
in Wisconsin
, where he was an observer and an optician. There he assisted George W. Ritchey
who built many of America's first large reflecting telescope
s. In 1908 he became an astronomer and instrument maker at the Mount Wilson Observatory
. Among his designs was the 100 inches (2,540 mm) telescope at that observatory, and a 50 feet (15.2 m) interferometer that he used to measure star diameters.
He was a long time assistant to Albert A. Michelson
. In 1920, Michelson and Pease were able to use the Michelson stellar interferometer
fitted to the 100 inches (2,540 mm) telescope at Mt. Wilson to measure the angular diameter of the star Betelgeuse
. Their estimate of 0.047" was very close to the value that Eddington
had predicted.
He would later be involved in the design of the 200 inches (5,080 mm) Hale Telescope
at the Mount Palomar Observatory. In 1928 he made the first discovery of a planetary nebula
within a globular cluster
(M15
).
The crater Pease
on the Moon
is named after him.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
.
He joined the Yerkes Observatory
Yerkes Observatory
Yerkes Observatory is an astronomical observatory operated by the University of Chicago in Williams Bay, Wisconsin. The observatory, which calls itself "the birthplace of modern astrophysics," was founded in 1897 by George Ellery Hale and financed by Charles T. Yerkes...
in Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
, where he was an observer and an optician. There he assisted George W. Ritchey
George Willis Ritchey
George Willis Ritchey was an American optician and telescope maker and astronomer born at Tuppers Plains, Ohio....
who built many of America's first large reflecting telescope
Reflecting telescope
A reflecting telescope is an optical telescope which uses a single or combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century as an alternative to the refracting telescope which, at that time, was a design that suffered from...
s. In 1908 he became an astronomer and instrument maker at the Mount Wilson Observatory
Mount Wilson Observatory
The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles...
. Among his designs was the 100 inches (2,540 mm) telescope at that observatory, and a 50 feet (15.2 m) interferometer that he used to measure star diameters.
He was a long time assistant to Albert A. Michelson
Albert Abraham Michelson
Albert Abraham Michelson was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment. In 1907 he received the Nobel Prize in Physics...
. In 1920, Michelson and Pease were able to use the Michelson stellar interferometer
Michelson stellar interferometer
The Michelson stellar interferometer is one of the earliest astronomical interferometers built and used. The interferometer was proposed by Albert Michelson in 1890, following a suggestion by Hippolyte Fizeau....
fitted to the 100 inches (2,540 mm) telescope at Mt. Wilson to measure the angular diameter of the star Betelgeuse
Betelgeuse
Betelgeuse, also known by its Bayer designation Alpha Orionis , is the eighth brightest star in the night sky and second brightest star in the constellation of Orion, outshining its neighbour Rigel only rarely...
. Their estimate of 0.047" was very close to the value that Eddington
Arthur Stanley Eddington
Sir Arthur Stanley Eddington, OM, FRS was a British astrophysicist of the early 20th century. He was also a philosopher of science and a popularizer of science...
had predicted.
He would later be involved in the design of the 200 inches (5,080 mm) Hale Telescope
Hale telescope
The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in California, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation, he orchestrated the planning, design, and construction of the observatory, but did not live to see its commissioning...
at the Mount Palomar Observatory. In 1928 he made the first discovery of a planetary nebula
Planetary nebula
A planetary nebula is an emission nebula consisting of an expanding glowing shell of ionized gas ejected during the asymptotic giant branch phase of certain types of stars late in their life...
within a globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
(M15
Messier 15
Messier 15 or M15 is a globular cluster in the constellation Pegasus. It was discovered by Jean-Dominique Maraldi in 1746 and included in Charles Messier's catalogue of comet-like objects in 1764...
).
The crater Pease
Pease (crater)
Pease is a lunar impact crater that lies in the north-northwestern edge of the huge skirt of ejecta that surrounds the Mare Orientale impact basin. It lies just over one crater diameter to the east of the smaller crater Butlerov. To the east-northeast of Pease is the somewhat larger Nobel.This is a...
on the Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.
See also
- History of astronomical interferometry
- List of astronomical instrument makers