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Henize, K. G.

Publications and source records attributed to Henize, K. G..

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

Observations of southern emission-line stars

A catalog of 1929 stars showing H-alpha emission on photographic plates is presented which covers the entire southern sky south of declination -25 deg to a red limiting magnitude of about 11.0. The catalog provides previous designations of known emission-line stars equatorial (1900) and galactic coordinates, visual and photographic magnitudes, H-alpha emission parameters, spectral types, and notes on unusual spectral features. The objects listed include 16 M stars, 25 S stars, 37 carbon stars, 20 symbiotic stars, 40 confirmed or suspected T Tauri stars, 16 novae, 14 planetary nebulae, 11 P Cygni stars, 9 Bep stars, 87 confirmed or suspected Wolf-Rayet stars, and 26 'peculiar' stars. Two new T associations are discovered, one in Lupus and one in Chamaeleon. Objects with variations in continuum or H-alpha intensity are noted, and the distribution by spectral type is analyzed. It is found that the sky distribution of these emission-line stars shows significant concentrations in the region of the small Sagittarius cloud and in the Carina region.

Henize, K. G.↗
NASA NTRS1976

Skylab ultraviolet stellar spectra - Cool stars with hot secondaries

A hot companion to the G5 III star HR 3080, a single-line spectroscopic binary, has been discovered from spectra in the vacuum-ultraviolet. The companion must be a subdwarf or pre-white dwarf. A list of previously known systems of the zeta Aur and VV Cep type observed with the ultraviolet spectrograph on Skylab is also given.

Parsons, S. B.↗
NASA NTRS1976

The Skylab S019 ultraviolet spectra of HD 153919 (=3U 1700-37) and HDE 226868 (=Cyg X-1)

Ultraviolet spectra of HD153919 (=3U1700-37) and HDE226868 (=Cyg X-1) were obtained with the ultraviolet objective-prism spectrograph of Skylab Experiment S019. The data consist of unwidened spectra which extend to 1,600A for HD153919 and to 2,400A for HDE226868. The wavelength resolution is about 2A to 1,400A and 12A at 2,000A. For HD153919, an unwidened spectrum of fair quality and extending to a wavelength of 1,600A was obtained at 22 sup h 08 sup m on 1 September 1973. The energy distribution in this spectrum generally resembles that of other reddened O stars. A break in continuum intensity seems to occur at a wavelength of about 1,720A. There is a suggestion of an emission line on the longward edge of the break but this could be either a chance clumping of grains or else a photographic edge-effect caused by the break.

Kondo, Y.↗
NASA NTRS1976

Ultraviolet stellar spectra obtained on Skylab

A 15-cm aperture f/3 Ritchey-Chretien telescope equipped with a 4 deg calcium fluoride prism was employed in taking objective prism spectra from 1300 to 5000 A in 188 stars, in the three Skylab missions. Spectra of 2 A resolution at 1400 A and 10 A at 2000 A, extending to B0 stars such that V equals 6.5, were taken of 400 stars in the neighborhood of 1500 A. Stellar temperature and luminosity variations are revealed in resonance lines of C IV and Si IV. Profiles of P Cygni type show up in the spectra of all stars with absolute bolometric magnitudes brighter than minus 8.4, implying appreciable outflow of mass. Spectra with emission lines shortward of 2000 A were obtained for 12 WR stars, and spectra of some companion stars dominating the UV spectra are reported.

Henize, K. G.↗
NASA NTRS1975

Ultraviolet stellar astronomy

The author has identified the following significant results. During all three Skylab missions, prism-on observations were obtained in 188 starfields and prism-off observations in 31 starfields. In general, the fields are concentrated in the Milky Way where the frequency of hot stars is highest. These fields cover an area approximately 3660 degrees and include roughly 24 percent of a band 30 deg wide centered on the plane of the Milky Way. A census of stars in the prism-on fields shows that nearly 6,000 stars have measurable flux data at a wavelength of 2600A, that 1,600 have measurable data at 2000A, and that 400 show useful data at 1500A. Obvious absorption or emission features shortward of 2000A are visible in approximately 120 stars. This represents a bonanza of data useful for statistical studies of stellar classification and of interstellar reddening as well as for studies of various types of peculiar stars.

Henize, K. G.↗
NASA NTRS1975

The very slow nova He 3-558

The emission-line object He 3-558 has been found to be a very slow nova which rose to maximum brightness in 1948 and is probably still fading. Its spectrum and light curve are described, and a distance of 3.5 kpc is derived. No sign of an earlier outburst was found in the Harvard collection of photographs.

Henize, K. G.↗
NASA NTRS1975

Skylab ultraviolet stellar spectra - Variation of intensity and structure of strong lines with temperature and luminosity

Objective-prism spectra at ultraviolet wavelengths extending to 1300 A were photographed during the three Skylab missions in a survey covering 9 percent of the sky. Several spectral features, notably resonance lines of C IV and Si IV, show striking variations with stellar temperature and luminosity. Marked P Cygni profiles in C IV and Si IV, indicative of significant outflow of mass, appear in the spectra of all stars with bolometric magnitude brighter than -8.4.

Henize, K. G.↗
NASA NTRS1975

Ultraviolet spectrophotometry from Gemini 11 of stars in Orion

Ultraviolet spectrophotometry in the wavelength region 2600-3600 A is reported for the bright early-type stars beta, eta, gamma, delta, iota, epsilon, sigma, zeta, and kappa Ori. The results are in good agreement with other observations, and, with the possible exception of the supergiants, are in good agreement with recent line-blanketed model atmospheres. There is evidence that the supergiants possess a small ultraviolet deficiency shortward of 3000 A relative to main-sequence stars of similar spectral type. The most extreme example of this phenomenon is the star kappa Ori.

Morgan, T. H.↗
NASA NTRS1975

The light curve of Comet Kohoutek

Visual estimates of total coma brightness define the light curve of Comet Kohoutek between Nov. 24, 1974 and Feb. 6, 1974. These data are well fitted by straight lines on the M-log r diagram. The preperihelion value of n is 2.2, and the post perihelion value is 3.8 up to January 16. A standstill in the decline is suspected between January 16 and 19. If the standstill is ignored the postperihelion data can be fitted less precisely by a single line with n equals 3.3. From photoelectric measures on four nights between January 5 and 13 after perihelion, n is found to be 4.1. The average B-V with a 32.4 arc sec diaphragm for those four nights is about 0.79; no clear systematic variation with time is noted.

Angione, R. J.↗
NASA NTRS1974

Ultraviolet spectrophotometry of Sirius from Gemini 12

The spectral energy distribution of Sirius between 2500 and 3700 A at a resolution of 7 A is obtained from plates taken on Gemini 12. The agreement with other observations and the most recent line-blanketed model atmospheres is good. The equivalent width of the Mg II doublet near 2800 A is 6.0 A, if the continuum level is represented by regions near 2650 and 2910 A. This is consistent with expectations for a hot Am star and implies line blocking of up to 15% in this wavelength region.

Spear, G. G.↗
NASA NTRS1974

Ultraviolet stellar spectra obtained with Skylab Experiment S019

Ultraviolet stellar spectra in the wavelength region from 130 to 500 nm were photographed during the three manned Skylab missions using a 15-cm-aperture objective-prism telescope mounted on the antisolar scientific airlock. Data at wavelengths of 200 nm or shorter were obtained for 1400 stars in 166 fields. Approximately 300 stars show absorption lines of Si IV, C IV, or C II in which the strengths and profiles show striking variations with stellar temperature and luminosity. Numerous weak lines are also observed in supergiant stars, shell stars, peculiar A stars, and Wolf-Rayet stars. Observations of comet Kohoutek show interesting variations in the strength of the OH 3090 A band.

Henize, K. G.↗
NASA NTRS1974

The peculiar star He 2-177 - A slow nova and a possible X-ray source

The remarkable detail resemblence of the spectrum of the peculiar emission-line star He 2-177 to that of the slow nova RR Telescopii is illustrated by tabulated data and discussed. The evolution of the spectrum since 1965 closely resembles the evolution of RR Tel between 1951 and 1954. A newly determined position of X-ray source 2U 1639-62 makes its identification with He 2-177 less probable than before.

Carlson, E. D.↗
NASA NTRS1973

Astronomy through the Skylab scientific airlocks.

Description of Skylab astronomy experiments (other than the Apollo Telescope Mount experiments) designed to study the earth's atmosphere, particles near the spacecraft, various components of the background skylight, the spectra of the sun, and the features of stars, nebulae, and galaxies. Emphasis is placed on the eight experiments that will operate through the scientific airlocks in the Orbital Workshop. The major features of equipment to be used in each experiment are outlined together with characteristics and relevance of information expected in each case.

Henize, K. G.↗
NASA NTRS1973

Emission-line stars in the Chamaeleon T association.

Objective-prism spectrum surveys conducted in 1962 and in 1970 reveal 32 stars showing H-alpha emission in the region of the Chamaeleon T association. Twelve of these stars show variations in either continuum intensity or H-alpha intensity. The magnitudes range from V equals 8.4 (spectrum B9.5 Ve) to approximately 16. Slit spectra have been obtained of 13 stars. Seven show classifiable absorption-line spectra, four show completely veiled continua, and two lack blue spectra. The veiling is strongly correlated with variability. The second brightest emission-line star, CD - 76 486, shows significant spectrum variations between 1962 and 1972.

Henize, K. G.↗
NASA NTRS1972

Manned versus unmanned space-based astronomy.

Discussion of the pros and cons of manned and unmanned space-based astronomical observatory systems. Rather than compete with one another, manned and unmanned systems, it is felt, should complement themselves mutually. The paramount factor inhibiting the growth of both manned and unmanned systems is shown to be the high cost per pound of payload equipment. The main hope for reducing this cost is the advent of a space station or shuttle sortie mode of operation in which the frequency of flights will reduce the necessity to guarantee experiment success. This, in turn, should reduce the complexity of experiment management and the cost of experiment hardware.

Henize, K. G.↗
NASA NTRS1971

Experiment S013: Ultraviolet astronomical camera

Recordings of the stellar ultraviolet radiation in the wavelength region from 2000 to 4000 angstroms are reported. An analysis of the surface temperatures of the stars, the absorption effects occurring in the atmospheres of the stars, and the absorption effects of the interstellar dust is made from the photographic data obtained. In addition to gathering basic astrophysical data about hot, young stars, the experiment is used to clarify the problems and techniques of uv photography of stars from manned spacecraft.

Henize, K. G.↗