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Code, A. D.

Publications and source records attributed to Code, A. D..

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Empirical effective temperatures and bolometric corrections for early-type stars

An empirical effective temperature for a star can be found by measuring its apparent angular diameter and absolute flux distribution. The angular diameters of 32 bright stars in the spectral range O5f to F8 have recently been measured with the stellar interferometer at Narrabri Observatory, and their absolute flux distributions have been found by combining observations of ultraviolet flux from the Orbiting Astronomical Observatory (OAO-2) with ground-based photometry. In this paper, these data have been combined to derive empirical effective temperatures and bolometric corrections for these 32 stars.

Code, A. D.↗
NASA NTRS1975

Study for application of a sounding rocket experiment to spacelab/shuttle mission

An inexpensive adaptation of rocket-size packages to Spacelab/Shuttle use was studied. A two-flight project extending over two years was baselined, requiring 80 man-months of effort. It was concluded that testing should be held to a minimum since rocket packages seem to be able to tolerate shuttle vibration and noise levels. A standard, flexible control and data collection language such as FORTH should be used rather than a computation language such as FORTRAN in order to hold programming costs to a minimum.

Code, A. D.↗
NASA NTRS1972

Ultraviolet observations of comets

The first observations of a comet in the vacuum ultraviolet were obtained on January 14, 1970, when OAO-2 recorded the spectrum of the bright comet Tago-Sato-Kosaka (1969g). The observations revealed, among other things, the predicted extensive hydrogen Lyman alpha halo. OAO-2 continued to collect spectrophotometric measurements of this comet throughout January of that year; a photograph of the nucleus in Lyman alpha revealed finer scale structures. In February of 1970, the bright comet Bennet (1969i) became favorable for space observations. On the basis of the OAO discovery, OGO-V made several measurements of comet Bennet with low spatial resolution photometers. Comet Enke was detected by OGO in January of 1971 at a large heliocentric distance from its Lyman alpha emission.

Code, A. D.↗
NASA NTRS1972

Absolute calibration of ultraviolet filter photometry

The essential features of the calibration procedure can be divided into three parts. First, the shape of the bandpass of each photometer was determined by measuring the transmissions of the individual optical components and also by measuring the response of the photometer as a whole. Secondly, each photometer was placed in the essentially-collimated synchrotron radiation bundle maintained at a constant intensity level, and the output signal was determined from about 100 points on the objective. Finally, two or three points on the objective were illuminated by synchrotron radiation at several different intensity levels covering the dynamic range of the photometers. The output signals were placed on an absolute basis by the electron counting technique described earlier.

Bless, R. C.↗
NASA NTRS1972

Ultraviolet photometry of Nova Serpentis 1970

The appearance of the bright nova, Nova Serpentis 1970, provided the first opportunity to obtain spectrophotometric observations of a nova in the vacuum ultraviolet. OAO-2 carried out systematic measurements from shortly after outburst on through the first sixty days of nova activity. This data consist of filter photometry and spectral scans. General characteristics of the light and spectral variations in the ultraviolet exhibited by this set of data are described.

Code, A. D.↗
NASA NTRS1972

Ultraviolet photometry of globular clusters

Filter photometry measurements of the integrated light from several globular clusters between 1500 and 4000 A are discussed. The techniques and problems associated with carrying out photometry of faint extended sources with the OAO-2 instrumentation are described first. The energy distribution for globular clusters determined from these data are corrected for interstellar extinction on the basis of B-V color excesses and a mean ultraviolet extinction curve. The results are compared with synthetic cluster calculations. The ultraviolet energy distribution is primarily determined by the number of stars at the blue end of the horizontal branch.

Welch, G. A.↗
NASA NTRS1972

Preliminary results of OAO ultraviolet photoelectric photometry of galaxies

General results are presented based on nearly completed reductions of data for approximately 35 galaxies of all Hubble types. In general the visual and ultraviolet energy distributions are well correlated. The energy distribution in late-type galaxies appears to turn up sharply in the region around 2000 A, and this is tentatively interpreted as due to the presence of early-type stars whose energy distribution is modified by interstellar dust within these objects. Similar turnups may be present in several elliptical galaxies but the evidence at this time is not definitive.

Code, A. D.↗