Hyron Spinrad
Encyclopedia
Hyron Spinrad is an American
astronomer
. His research has ranged from the study of planet
atmosphere
s to the evolution of galaxies. As of 2010, he is an emeritus professor of astronomy
at the University of California, Berkeley
.
, he received a Bachelor of Arts
in astronomy at UC Berkeley. Following graduation, he enrolled in the US Army, and began work in the Army Map Service. After two years in the army, he applied to and was accepted to the graduate program at UC Berkeley in 1957. He earned his PhD
in 1961, writing his thesis on stellar populations in galactic nuclei. He then took a position as a research scientist at the Jet Propulsion Laboratory
, where he performed spectroscopic studies of Solar System
planet
s and smaller bodies. In 1964, Spinrad was invited to return to Berkeley as a professor, a position he has held since, and in 1968, he received tenure.
planet
s and comet
s. These diverse topics are united in that Spinrad primarily relied upon measurements of spectral line
s, known as spectroscopy
, in his work.
as a result of the speed of light
being finite. In general, this allows astronomers to study objects as they were many millions or even billions of years ago. Spinrad originally selected targets by looking at the position of members of the Third Cambridge Catalogue of Radio Sources
, as the catalogue included many radio galaxies
that he thought would be at high redshift. The search was successful, as Spinrad set the record for the highest identified redshift for a galaxy in 1975, and then broke his record several times, including the first identification of a galaxy with a redshift larger than z = 1. These discoveries helped show how galaxies have evolved throughout the history of the universe. For example, by measuring redshifts of sources in the Third Cambridge Catalogue of Radio Sources, it was possible to establish the number of such bright radio galaxies per volume in the universe as a function of its age, and find that there were hundreds as times as many radio galaxies at z
1 as there are today.
in the atmosphere of Mars
, and derivation of the abundance of carbon dioxide
in Mars' atmosphere, from which he and his collaborators inferred that Mars has an atmosphere very much more tenuous than that of Earth.
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...
. His research has ranged from the study of planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
s to the evolution of galaxies. As of 2010, he is an emeritus professor of astronomy
Astronomy
Astronomy is a natural science that deals with the study of celestial objects and phenomena that originate outside the atmosphere of Earth...
at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
.
Biography
Spinrad was born in New York in 1934. After his family moved to CaliforniaCalifornia
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
, he received a Bachelor of Arts
Bachelor of Arts
A Bachelor of Arts , from the Latin artium baccalaureus, is a bachelor's degree awarded for an undergraduate course or program in either the liberal arts, the sciences, or both...
in astronomy at UC Berkeley. Following graduation, he enrolled in the US Army, and began work in the Army Map Service. After two years in the army, he applied to and was accepted to the graduate program at UC Berkeley in 1957. He earned his PhD
PHD
PHD may refer to:*Ph.D., a doctorate of philosophy*Ph.D. , a 1980s British group*PHD finger, a protein sequence*PHD Mountain Software, an outdoor clothing and equipment company*PhD Docbook renderer, an XML renderer...
in 1961, writing his thesis on stellar populations in galactic nuclei. He then took a position as a research scientist at the Jet Propulsion Laboratory
Jet Propulsion Laboratory
Jet Propulsion Laboratory is a federally funded research and development center and NASA field center located in the San Gabriel Valley area of Los Angeles County, California, United States. The facility is headquartered in the city of Pasadena on the border of La Cañada Flintridge and Pasadena...
, where he performed spectroscopic studies of Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s and smaller bodies. In 1964, Spinrad was invited to return to Berkeley as a professor, a position he has held since, and in 1968, he received tenure.
Research
Spinrad has pursued research in a variety of areas of astronomy, including stellar composition, the formation and evolution of galaxies, and the composition of the atmospheres of Solar SystemSolar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...
s and comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s. These diverse topics are united in that Spinrad primarily relied upon measurements of spectral line
Spectral line
A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from a deficiency or excess of photons in a narrow frequency range, compared with the nearby frequencies.- Types of line spectra :...
s, known as spectroscopy
Spectroscopy
Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative...
, in his work.
Galaxy formation and evolution
To study the formation of galaxies, Spinrad looked for distant galaxies. The more distant an object, the longer it takes light to reach EarthEarth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
as a result of the speed of light
Speed of light
The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time...
being finite. In general, this allows astronomers to study objects as they were many millions or even billions of years ago. Spinrad originally selected targets by looking at the position of members of the Third Cambridge Catalogue of Radio Sources
Third Cambridge Catalogue of Radio Sources
The Third Cambridge Catalogue of Radio Sources is an astronomical catalogue of celestial radio sources detected originally at 159 MHz, and subsequently at 178 MHz. It was published in 1959 by members of the Radio Astronomy Group of the University of Cambridge...
, as the catalogue included many radio galaxies
Radio galaxy
Radio galaxies and their relatives, radio-loud quasars and blazars, are types of active galaxy that are very luminous at radio wavelengths, with luminosities up to 1039 W between 10 MHz and 100 GHz. The radio emission is due to the synchrotron process...
that he thought would be at high redshift. The search was successful, as Spinrad set the record for the highest identified redshift for a galaxy in 1975, and then broke his record several times, including the first identification of a galaxy with a redshift larger than z = 1. These discoveries helped show how galaxies have evolved throughout the history of the universe. For example, by measuring redshifts of sources in the Third Cambridge Catalogue of Radio Sources, it was possible to establish the number of such bright radio galaxies per volume in the universe as a function of its age, and find that there were hundreds as times as many radio galaxies at z
1 as there are today.Solar System bodies
Spinrad spent much of his time at the Jet Propulsion Laboratory looking at the atmospheres of Solar System planets. His achievements included the discovery of water vaporWater vapor
Water vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...
in the atmosphere of Mars
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
, and derivation of the abundance of carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
in Mars' atmosphere, from which he and his collaborators inferred that Mars has an atmosphere very much more tenuous than that of Earth.
Honors
- AsteroidAsteroidAsteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
3207 Spinrad3207 Spinrad3207 Spinrad is a main-belt asteroid discovered on March 2, 1981 by S. J. Bus at Siding Spring.- External links :*...
, discovered in 1981, was named for Hyron Spinrad - Heineman PrizeDannie Heineman Prize for AstrophysicsThe Dannie Heineman Prize for Astrophysics is jointly awarded each year by the American Astronomical Society and American Institute of Physics for outstanding work in astrophysics. It is funded by the Heineman Foundation in honour of Dannie Heineman....
in 1986 for outstanding work in astrophysics - Member of the National Academy of SciencesUnited States National Academy of SciencesThe National Academy of Sciences is a corporation in the United States whose members serve pro bono as "advisers to the nation on science, engineering, and medicine." As a national academy, new members of the organization are elected annually by current members, based on their distinguished and...