Showing papers by "Roger H. Hildebrand published in 1980"
TL;DR: In this paper, a far-infrared and sub-millimeter continuum emission from the dark globule B335 was observed and the spectrum is that of optically thin thermal emission from dust with temperature 13-16 K. The estimated dust mass is 0.07-0.17 solar masses.
Abstract: Far-infrared and submillimeter continuum emission from the dark globule B335 was observed. The spectrum is that of optically thin thermal emission from dust with temperature 13-16 K. The estimated dust mass is 0.07-0.17 solar masses. The observed luminosity, 5 solar luminosities, can be supplied by the interstellar radiation field.
27 citations
TL;DR: In this paper, the design and performance of an f/35 submillimeter photometer are discussed, and the performance of the photometer is evaluated under good atmospheric conditions, with a broad-band 400 micron sensitivity of approximately 1.5 Jy.
Abstract: The design and performance of an f/35 submillimeter photometer are discussed. It is noted that the instrument provides for both broad- and medium-width passbands between 350 microns and 2 mm and for beam sizes between 28 arcsec and 100 arcsec FWHM. Under good atmospheric conditions, a broad-band 400 micron sensitivity of approximately 1.5 Jy is found to be obtainable in one hour. A description is given of the photometer's support housing, submillimeter radiometer, and electronics and data-handling system. In evaluating the performance, attention is given to sensitivity, beam profiles, and the effect of changes in the aperture on the signal.
12 citations
TL;DR: In this paper, high-speed photometric observations of the dwarf nova AH Her on nine consecutive days during an outburst have been made, and rapid coherent oscillations on every day except two near maximum light have been detected.
Abstract: High-speed photometric observations of the dwarf nova AH Her on nine consecutive days during an outburst have been made, and rapid coherent oscillations on every day except two near maximum light have been detected. The period, amplitude, and luminosity for each day is presented and the progression of the periods is discussed.
10 citations
TL;DR: Both the bright and dark hemispheres of Iapetus were observed in one broadband filter with a flux-weighted mean wavelength approximately equal to 66 microns.
8 citations
TL;DR: The observed brightness temperatures fall below the predictions of atmospheric models constructed from data at shorter wavelenths, indicating the presence of an opacity source besides pressure-broadened hydrogen lines in the submillimeter region.
Abstract: Observations at wavelengths longer than 300 microns provide temperature measurements at deeper layers in the atmosphere of giant planets because opacities are reduced. Submillimeter observations of Saturn were made in November 1979 when the inclination angle of the rings was 1.2 degrees. A 55 sec focal plane aperture was used along with two filters with spectral passbands of 300 to 800 microns (mean wavelength approximately 400 microns) and 500 to 850 microns (mean wavelength approximately 700). Mean brightness temperatures of 121 + or - 12 K at 400 microns and 139 + or - 15 K at 700 microns are reported. The brightness temperatures fall below predictions of atmospheric models at shorter wavelengths, requiring an opacity source besides the pressure-broadened hydrogen lines. In combination with measurements at larger inclination angles, the results yield a 400 micrometer brightness temperature for the rings of approximately 75 K.
7 citations