NEWKIRK, Gordon A. Jr. (1928 - 1985)

Was an astrophicist that gained world renown as a solar physicist, and will probably be most remembered, in science, for a series of pioneering achievements in designing and perfecting fundamental instruments for observing the solar corona, in and out of eclipse.

He was born in Orange, New Jersey on June 12, 1928. His father was an electrical engineer for Public Service Electric and Gas. While at high school, he became interested in astronomy and built a six inch mirror telescope and a spectrograph. Newkirk began his college career in the Astronomy Department at Harvard University in the fall of 1946. His interest in solar work began while working at the Agassiz Observatory where he learned to operate the telescope, the catalog camera and the meteor camera. He also built a guider for a photospheric camera.

In 1950, Newkirk attended the University of Michigan for his graduate work where he received his Ph.D. in astrophysics with a thesis entitled Carbon Monoxide in the Solar Atmosphere. A little time after Newkirk was drafted by the United States Army. After completing basic training at Fort Bliss, Texas, he was assigned as an astronomer to the Meteorological Group of the Signal Corps Engineering Labs in New Jersey. While calculating the effects of wind response on rockets, Newkirk became interested in atmospheric optics. He first began measuring the brightness of the sky near the sun and the light scattering properties of the atmosphere. Encouraged by his findings, he began to correspond with Jack Evans and Walt Roberts at the High Altitude Observatory (HAO) in Colorado and, in the fall of 1954, he was re-assigned to Boulder, to assemble the visual sky photometer instrument, which could photographically record the atmosphere at varying levels.

Upon being discharged from the Army in 1955, he accepted a senior position at the HAO where he began to work in the development of a coronagraph that was to be used to study the scattered light from the electron corona. Two years later, he became interested in measuring sky brightness as a function of altitude using a sky photometer attached to a manned balloon. The first mission was carried out in August 1959, under the STRATOLAB navy manned balloon program, from the Stratobowl in South Dakota. The open gondola that carried the instrument to an elevation of 40,000 feet, was piloted by Malcolm Ross (US Navy) and Robert H. Cooper (HAO).

In the fall of that same year, HAO inherited the gondola originally used by Princeton's physicist Martin Schwarzschild for the Stratoscope I program. Newkirk used that platform to developing an unmanned stratospheric balloon experiment to raise a coronagraph, dubbed Coronascope I. The objective was to climb above the dust and smoke of the lower atmosphere for several hours of continuous operation, and after taking measurements of sky brightness, the gondola would be returned to the ground by a parachute. In the fall of 1960, after a failed first attempt, Coronascope I had two successful flights reaching an elevation of 80,000 feet outside Minneapolis.

The Coronascope II, a more avanced version of the instrument featuring a multiple occulting disk to operate in the near infrared, was flown over Texas in March of 1964 and produced the first images of the outer corona without a solar eclipse. His final attempt with a balloon mission was carried out in June of 1970, when Newkirk retrofitted the orbital coronagraph he had built for Skylab and flew it succesfully.

By 1973, he the orbital ATM coronagraph was launched into space on the Skylab satellite. In 1980, the coronagraph was launched on the Solar Maximum Mission (SMM) satellite.

In addition to his pioneering achievements in designing and perfecting instruments for observing the solar corona, Newkirk published other papers on the solar corona, including a benchmark depiction of coronal magnetic fields, derived analytically from magnetograph observations of the surface of the sun. He also wrote about the atmosphere of Venus, the scattering of light and the distribution of small particles in the upper atmosphere, solar flares, the paradox of the faint, early sun, the solar constant, the solar cycle and solar seismology, the interpretation of cosmogenic nuclides in polar ice cores, and the scattering of galactic cosmic rays. His model of the electron corona -based on the interpretation of coronal photometry data from Climax- which was published in 1958 remains today as a standard reference model.

In the academic side of his career, between 1956 and 1985, Newkirk was a professor at the University of Colorado in the Department of AstroGeophysics and the Department of Physics and Astrophysics. In 1968, Newkirk succeeded Walt Roberts and John Firor as director of HAO and associate Director of NCAR, serving until 1979. He also was a longstanding member of many scientific societies. In 1972, he was elected chairman of the Solar Physics Division of the American Astronomical Society. Subsequently, Newkirk chaired the committee that established the Hale Prize. In 1976, Newkirk was elected as President of the Commission on Solar Activity of the International Astronomical Union and member of the Geophysics Research Board of the National Academy of Sciences.

On December 21, 1985 he died after a long battle with cancer.

Related Entries

External Links

Interview with Dr. Gordon Newkirk  by David DeVorkin