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Duthie, J. G.

Publications and source records attributed to Duthie, J. G..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Optical studies of the regions of the gamma-ray bursts of 19 November, 1978 and 5 March, 1979

Optical studies were made of two well-located gamma-ray burst regions in the Southern Hemisphere using the 1.5 m telescope at the Cerro Tololo Inter-American Observatory in Chile. Multi-filter image tube plates and UBV photometry surveys were made of both regions. The field of the 19 November, 1978 gamma-ray burst shows no early star or star with unusual colors out to several diameters of the nominal error box. The region of the 5 March, 1979 gamma-ray burst, which includes N49, contains several blue giants in the LMC, two of which deserve further study.

Fishman, G. J.↗
NASA NTRS1979

An upper limit on ultraviolet shot noise from Cygnus X-1

Rapid photometry of Cygnus X-1 through an ultraviolet filter centered on 0.35 micron has been obtained at 100-ms sampling intervals. The autocorrelation function of these data has been examined for shot noise analogous to the behavior of the X-ray light curve. The ultraviolet data are entirely consistent with white noise. Considering randomly occurring ultraviolet shots with the same duration (0.5 s) and average rate (1 per sec) as the X-ray shots, a 3-sigma upper limit on the ratio of optical to X-ray energies per shot is estimated to be 0.13, before the ultraviolet light is attenuated by interstellar dust. This limit is then generalized for shots of arbitrary duration and rate.

Duthie, J. G.↗
NASA NTRS1978

Martian occultation of epsilon Gem as observed from the C. E. Kenneth Mees Observatory

Ground-based observations of the occultation of epsilon Gem by Mars on April 8, 1976 have been reduced to yield the scale height and temperature profiles of the Martian atmosphere for number densities between 10 to the 13th and 10 to the 15th per cu cm. The deduced variations in temperature are remarkably similar to the in situ measurements from the Viking landers.

French, R. G.↗
NASA NTRS1978

Lamellar grating observations of the Orion Nebula from 100 to 500 microns

Results are presented for spectroscopic observations of the Kleinmann-Low nebula in the 100-500-micron region taken from the Kupier Airborne Observatory. These results, in conjunction with previous work at shorter wavelengths, are consistent with a dilute blackbody spectrum modified by grain emissivity and spatial variations in the grain density.

Pipher, J. L.↗
NASA NTRS1977

Spherical lamellar grating interferometer for airborne astronomical observations of far infrared objects

A lamellar-grating interferometer designed for airborne IR astronomy is described, and its response to a laboratory far-IR source and to Jupiter as viewed from NASA's Kuiper Airborne Observatory is discussed. The theory of lamellar-grating interferometers is reviewed, advantages over Michelson interferometers are noted, and the optical arrangement for the lamellar-grating instrument is indicated. The response of the instrument is illustrated using purged and unpurged spectra of a 1000-K blackbody source as well as a raw spectrum of Jupiter containing many absorption features (probably telluric) identified with rotation bands of H2O. It is noted that the interferometer's self-collimation allows for efficient operation with a minimum of auxiliary optics.

Pipher, J. L.↗