Search Publications
Missions
Journals
Publication Years
Line formation in the wind of alf Cyg.
Praderie, F.; Kunasz, P. B.
In the considered investigation, the method reported by Mihalas et al. (1976) is used to search for plausible atmospheric models for Alpha Cyg and to find limits on its mass-loss rate. Assumptions about the wind and underlying photosphere, and the free parameters of the model are described. The best-suited numerical method is discussed and possibl…
Stephanian's star : the energy distribution reveals a nontypical cataclysmic variable.
Szkody, P.
Einstein, IUE, optical multichannel spectrophotometry, and IR observations of Stepanian's star are discussed in terms of other known cataclysmics. While the X-ray flux and IUE emission-line data are similar to that of dwarf novae, the total continuum flux distribution from uv-IR is cooler (peaking near a 10,000 K blackbody) and is unlike either a …
IUE MG II doublet observations in F and G main sequence stars.
Ponz, J. D.; Garcia-Alegre, M. C.; Vazquez, M.
Mg II resonance lines at 2800 A were studied in the spectra of F and G main sequence stars, observed with the IUE satellite in high resolution mode. Correlation with other chromospheric indicators were investigated and a search was conducted for the best candidates to continue further studies of differential rotation. An attempt has been made to s…
IUE observations of mass ejection by the close binary system AO Cas.
Kondo, Y.; McCluskey, G. E.
It is noted that 11 high-resolution spectra in the far-ultraviolet and two high-resolution spectra in the mid-ultraviolet were obtained. A high-velocity stellar wind exists as indicated by narrow shortward-displaced absorption features superposed on the P Cygni lines of N V, Si IV, and C IV. Absorption lines caused by N IV and C III are present an…
Transition region structure in F dwarfs.
Saxner, M.
Strong transition region line emission detected in the IUE spectra of two F dwarfs is discussed. The corresponding surface fluxes are found to be comparable to those of active binaries, such as RS CVn-systems. Line flux ratios formed from the multiplets Si IV 1394 A + 1403 A, C IV 1549 A, and N V 1240 A are used in deriving the structure of the tr…
HR 4511 : a probable cepheid with a supergiant-like hot companion.
Parsons, S. B.
IUE observations have shown HR 4511 to have an early B-type companion with a strong stellar wind. Fitting the energy distribution of the system from far-UV to middle-IR yields a difference of about 3.2 mag at the V passband. Since HR 4511 is in the small cluster Stock 14 and has M(V) = -7.8, M(V) for the secondary is about -4.6, which is only slig…
IUE observations of eight OB stars in NGC 2244 : ultraviolet continuaand extinction.
Massa, D.; Conti, P. S.
Low-resolution IUE ultraviolet continuum observations of O and B stars in the young open cluster NGC 2244 are presented. When only relative energy distributions are considered, thereby eliminating any dependence on reddening corrections or absolute energy calibrations, it is found that the ultraviolet energy distributions of the O stars have signi…
Evidence for autoionization and dielectronic recombination of SI II in the atmospheres of B-type stars.
Underhill, A. B.
Observations are reported demonstrating that both of the 3s3p3d 2F0 levels of Si II autoionize in the atmospheres of B-type stars. A justification is given for concluding that the 2F05/2 level which lies below the laboratory position for the 3s2(1S) limit of Si II, autoio…
Bolometric corrections of silicon stars.
North, P.
Low-dispersion spectrograms of two peculiar stars and of two normal ones were obtained with the IUE satellite in both wavelength ranges. Semi-empirical bolometric corrections were estimated from the observed ultraviolet fluxes and from theoretical fluxes best fitting the observed Geneva color indices.
IUE observations of X Per, the proposed optical counterpart of the X-ray source 4U 0352+30.
Bianchi, L.; Bernacca, P. L.
The O 9.5 (III-V) pe star X Persei, proposed optical counterpart of the X-ray source 4U 0352+30, has been observed on October 14, 1978, with the SWP Camera on board the IUE satellite in the low and high resolution modes. The ultraviolet continuum, in the range 1000-1900 A, can adequately be fitted to the emergent flux from a model atmosphere havin…