John Evan Baldwin
FRS (6 December 1931 – 7 December 2010) was a British
astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...
who worked at the
Cavendish Astrophysics Group
The Cavendish Astrophysics Group (formerly the Radio Astronomy Group) is based at the Cavendish Laboratory at the University of Cambridge. The group operates all of the telescopes at the Mullard Radio Astronomy Observatory except for the 32m MERL ...
Astrophysics Group members - John Baldwin
''mrao.cam.ac.uk'' (formerly Mullard Radio Astronomy Observatory) from 1954. He played a role in the development of interferometry
Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important inves ...
in Radio Astronomy
Radio astronomy is a subfield of astronomy that studies Astronomical object, celestial objects using radio waves. It started in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observat ...
, and later astronomical optical interferometry
Interferometry is a technique which uses the ''interference'' of superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, fiber opti ...
and lucky imaging
Lucky imaging (also called lucky exposures) is one form of speckle imaging used for astrophotography. Speckle imaging techniques use a high-speed camera with shutter speed, exposure times short enough (100 ms or less) so that the changes in ...
. He made the first maps of the radio emission from the Andromeda Galaxy
The Andromeda Galaxy is a barred spiral galaxy and is the nearest major galaxy to the Milky Way. It was originally named the Andromeda Nebula and is cataloged as Messier 31, M31, and NGC 224. Andromeda has a Galaxy#Isophotal diameter, D25 isop ...
and the Perseus Cluster
The Perseus cluster (Abell 426) is a cluster of galaxies in the constellation Perseus. It has a recession speed of 5,366 km/ s and a diameter of 863. It is one of the most massive objects in the known universe, containing thousands of galaxi ...
, and measured the properties of many active galaxies
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. Such e ...
. In 1985 he performed the first Aperture Masking Interferometry observations, and then led the construction and operation of the Cambridge Optical Aperture Synthesis Telescope
COAST, the Cambridge Optical Aperture Synthesis Telescope, is a multi-element optical astronomical interferometer with baselines of up to 100 metres, which uses aperture synthesis to observe stars with angular resolution as high as one thousand ...
, and helped develop the lucky imaging
Lucky imaging (also called lucky exposures) is one form of speckle imaging used for astrophotography. Speckle imaging techniques use a high-speed camera with shutter speed, exposure times short enough (100 ms or less) so that the changes in ...
method. In 2001 he was awarded the Jackson-Gwilt Medal
The Jackson-Gwilt Medal is an award that has been issued by the Royal Astronomical Society (RAS) since 1897. The original criteria were for the invention, improvement, or development of astronomical instrumentation or techniques; for achievement ...
for his technical contributions to the fields of interferometry
Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important inves ...
and aperture synthesis
Aperture synthesis or synthesis imaging is a type of interferometry that mixes signals from a collection of telescopes to produce images having the same angular resolution as an instrument the size of the entire collection. At each separation and ...
.
He matriculated as a member of Queens' College, Cambridge
Queens' College is a Colleges of the University of Cambridge, constituent college of the University of Cambridge. Queens' is one of the 16 "old colleges" of the university, and was founded in 1448 by Margaret of Anjou. Its buildings span the R ...
in 1949 and was a Life Fellow of the College from 1999 to his death in 2010.
References
External links
- John Baldwin's page at the MRAO
- Photo of John Baldwin
with Jan Hendrik Oort
Jan Hendrik Oort ( or ; 28 April 1900 – 5 November 1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. ''The New York Times'' called him ...
, Bob Rubin and Vera Rubin
1931 births
2010 deaths
20th-century British astronomers
Alumni of Queens' College, Cambridge
Fellows of Queens' College, Cambridge
Fellows of the Royal Society
{{UK-astronomer-stub