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Line Identifications in the Ultraviolet Spectrum of 31 Cygni
Bauer, Wendy Hagen; Stencel, Robert E.
Line identifications are presented for the Zeta Aur-type eclipsing binary system 31 Cyg (K4 Ib + B4 V). The rich absorption spectrum observed during chromospheric eclipse has been nearly completely identified. This list will be useful in analyzing spectra of related binaries, such as 32 Cyg and VV Cep. The large number of line transitions contribu…
The Ultraviolet Calibration of the Hubble Space Telescope. II. A Correction for the Change in Sensitivity of the SWP Camera on the IUE
Grillmair, Carl J.; Bohlin, Ralph C.
The IUE data on standard stars that will be the basis of UV absolute photometric calibration for the Hubble Space Telescope must be corrected for the changes that are apparent in the low-dispersion spectra of the five standard stars. A set of 895 spectra is presently analyzed in order to determine the change in sensitivity of the SWP camera for th…
Redshifts of High Temperature Emission Lines in the Far-Ultraviolet Spectra of Late-Type Stars. II. New, Precise Measurements of Dwarfs and Giants
Ayres, Thomas R.; Jensen, Eberhard; Engvold, Oddbjorn
Results are presented from an IUE SWP camera investigation of the occurrence of gasdynamic flows, analogous to the downdrafts of 10 to the 5th K material observed over magnetic active regions of the sun, among stars of late spectral type. The SWP calibration spectra study conducted documents the existence of local, small, persistent distortions of…
The Ultraviolet Spectrum of Noncoronal Late-Type Stars: The Gamma Crucis (M3.4 III) Reference Spectrum
Brown, Alexander; Johansson, Sveneric; Carpenter, Kenneth G. +3 more
A guide is presented to the UV spectrum of M-type giants and supergiants whose outer atmospheres contain warm chromospheres but not coronae. The M3 giant Gamma Crucis is taken as the archetype of the cooler, oxygen-rich, noncoronal stars. Line identifications and integrated line flux measurements of the chromospheric emission features seen in the …
The Ultraviolet Calibration of the Hubble Space Telescope. III. A Correction for the Change in Sensitivity of the LWR Camera on IUE
Grillmair, Carl J.; Bohlin, Ralph C.
The absolute photometric calibration of the Hubble Space Telescope (HST) in the UV will be based on low-dispersion spectra obtained by IUE. Therefore, these data must be corrected for the substantial changes observed in the sensitivities of the IUE SWP and LWR cameras. A previous paper specified the correction in 5 A bins for SWP through 1986.36. …
Galactic Interstellar Abundance Surveys with IUE. II. The Equivalent Widths and Column Densities
Shull, J. Michael; van Steenberg, Michael E.
This paper continues a survey of interstellar densities, abundances, and cloud structure in the Galaxy, using the International Ultraviolet Explorer (IUE) satellite. Equivalent widths of 18 ultraviolet resonance transitions are presented and column densities for Si II, Mn II, Fe II, S II, and Zn II toward 261 early-type stars are derived. These eq…
Carbon and Nitrogen Lines in the Spectra of Wolf-Rayet Stars
Bhatia, A. K.; Underhill, A. B.
Predictions of 29 energy ratios involving emission lines of He II, C II, C III, C IV, N III, N IV, and N V are presented. Comparison of observed energy ratios with the predicted energy ratios shows that WC spectra can be understood in terms of solar composition, T* = 2.5 × 104K, 5×104 ≤ Te ≤ 105
The Orbit of the Classical Cepheid SU Cygni
Evans, Nancy R.
New radial velocity data are presented for the classical Cepheid SU Cyg. An orbit has been derived from the new data, CORAVEL data by Imbert (1985) and data from 1906, and is presented in the paper. The pulsation radial velocity curves are compared from the plate material from David Dunlap Observatory (DDO) and several radial velocity spectrophoto…
Ultraviolet Observations by the IUE of 31 Clusters of the Large Magellanic Cloud
Cassatella, A.; Geyer, E. H.; Barbero, J.
Ultraviolet observations of 31 star clusters of the Large Magellanic Cloud obtained by the International Ultraviolet Explorer are presented. The clusters, mostly globular, span the range of ages from about 10 to the 7th to 10 to the 10th yr. The sample includes several young globular clusters, which have no counterpart in the Galaxy. The paper is …
Recurrent Episodic Mass Loss in a B2e Star: 66 Ophiuchi, 1982--1985
Sonneborn, George; Grady, C. A.; Wu, Chi-Chao +1 more
The results of three intensive ultraviolet monitoring campaigns for 66 Oph in September-October 1982, September 1983, and September 1984, supplemented by the available IUE archival data from April, 1982 to June, 1985 are reported. The stellar wind went through at least two and probably three episodes of weak-wind absorption. At wind minimum, the r…