Search Publications
High-resolution, far-ultraviolet study of beta Draconis (G2 Ib-II) : transition region structure and energy balance.
Jordan, C.; Stencel, R. E.; Linsky, J. L. +2 more
High-resolution far ultraviolet spectra of the star Beta Draconis have been obtained with the IUE satellite. The observations and emission line data from the spectra are presented, the interpretation of the emission line widths and shifts is discussed, and the implications are given in terms of atmospheric properties. The emission measure distribu…
IUE and ground-based observations of the Hubble-Sandage variables in M 31 and M 33.
Gull, T. R.; Humphreys, R. M.; D'Odorico, S. +2 more
Ultraviolet spectroscopy from the IUE, in combination with ground-based visual and infrared photometry, are used to determine the energy distributions of the luminous blue variables, the Hubble-Sandage variables, in M31 and M33. When corrected for interstellar extinction, the integrated energy distributions yield the total luminosities and blackbo…
Temporal and spatial behavior of the ultraviolet emissions of comet IRAS-Araki-Alcock 1983d
Feldman, P. D.; A'Hearn, M. F.; Millis, R. L.
The spatial distribution and temporal variation of the ultraviolet emissions from comet IRAS-Araki-Alcock 1983d, observed by IUE near closest approach of the comet to the earth, suggest a model for this comet of a rotating cometary nucleus with a nonuniform distribution of volatile ices. The short lifetime of S2 (about 500 s), a species whose pres…
Coordinated multifrequency observations of the BL Lacertae objects MRK 180 and MRK 501.
Kondo, Y.; Mushotzky, R. F.; Urry, C. M. +8 more
The continuous spectra of the nearby BL Lac objects Mrk 180 and Mrk 501 have been investigated by making coordinated observations at X-ray, ultraviolet, optical, and radio wavelengths. The observations were planned in order to obtain single-epoch snapshots, or time-frozen spectra, of the emission at many different wavelengths. The spectra were fit…
The ionization structure of planetary nebulae. IV. NGC 6853
Barker, T.
Upgraded UV and IR data were taken of the planetary nebula NGC 6853 in the same region as previous optical data to improve the data base on various ionized species in the nebula. The spectral range 1400-9600 A was scanned, and good agreement was obtained between UV and optical ionization abundance data, although the 4267 A C II line yielded a C(2+…
IUE observations of Centaurus X-4 during the 1979 May outburst.
Raymond, J. C.; Dupree, A. K.; Holm, A. V. +3 more
Ultraviolet spectrophotometry of the X-ray transient/burst source Centaurus X-4 at several intervals during the peak and decay of the May 1979 X-ray transient event was obtained. The spectrum was characterized by a blue continuum with alpha = 0.0 + or - 0.3 (F/nu/ varies as nu to the alpha power) and strong emission lines of N V lambda 1240, C IV …
Observations of interstellar hydrogen and deuterium toward Alpha Centauri A.
Moos, H. W.; Linsky, J. L.; Landsman, W. B. +1 more
The authors present a composite profile of the Lyα emission line of α Cen A, obtained from 10 individual spectra with the high-resolution spectrograph aboard the satellite. There is excellent overall agreement with two previous Copernicus observations. Interstellar deuterium is detected, and a lower limit is set on the deuterium to hydrogen ratio …
Ultraviolet extinction and diffuse band strength correlations.
Snow, T. P., Jr.; Seab, C. G.
Correlations between UV extinction parameters and diffuse band strengths are south, using a data base of 50 stars with recently measured extinction curves. A novel aspect of this study is that the basic dependence of most interstellar parameters on E(B-V) (or, nearly equivalently, on the total hydrogen column density) has been largely canceled out…
The remarkable ultraviolet spectrum of the planetary nebula Abell 30.
Feibelman, W. A.; Harrington, J. P.
Abell 30 has been identified as a planetary nebula in which the nucleus has experienced a final helium shell flash after ejection of the original, outer envelope. Around the central star of the nebula, four knots of material are observed. In view of the importance of the chemical composition of the ejected material for studies of advanced stages o…
The chromospheres of classical cepheids. II. High-resolution profilesof the MG II H and K lines.
Parsons, S. B.; Schmidt, E. G.
The profiles of the Mg II h and k lines near 2900 A are studied on the basis of IUE long wavelength camera high resolution spectra for a number of phases of each of five Cepheids. An emission feature often appears at the centers of the two lines, and there are central absorption features as well, due to interstellar or circumstellar gas, which are…