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Ultraviolet and coordinated; ground-based observations of A And.
Altamore, A.; Baratta, G. B.; Friedjung, M. +4 more
High- and low-resolution UV spectrograms of the symbiotic star Z Andromedae were made during 1978-79 with the International Ultraviolet Explorer (IUE) and coordinated with ground-based observations. The spectrograms extend from 1200 to 3341 A and show a rich emission line spectrum with a wide range of ionization energy, from O I, Mg I and II and F…
IUE observations of pre-main-sequence stars. I. MG II and CA II resonance line fluxes for T Tau stars.
Calvet, N.; Giampapa, M. S.; Imhoff, C. L. +1 more
IUE satellite and Lick 3 m reflector image tube scanner measurements of the Mg II and Ca II resonance lines in a sample of T Tauri stars are the basis of a discussion of the Mg II h and k line emission and the Ca II H and K line emission, within the context of stellar chromospheres. Corroborative evidence is presented for the chromospheric origin …
The ultraviolet spectrum of Herbig-Haro object 1.
Brugel, E. W.; Bohm-Vitense, E.; Boehm, K. H.
Continuum and emission line fluxes for HH 1 in the range of 1200-1300 A have been determined using IUE spectra, and it is found that the luminosity of HH 1 in this wavelength interval is slightly larger than 1 solar luminosity, or 20 times greater than for the wavelength range 3200-11,000 A. If averaged over intervals of 100 A, it is shown that th…
Simultaneous X-ray, ultraviolet, optical, and radio observations of the flare star Proxima Centauri
Quinn, P. J.; Linsky, J. L.; Haisch, B. M. +7 more
Results of coordinated program of observations in the X-ray, UV, optical and radio regions of the dM5e flare star Proxima Centauri are presented. Simultaneous observations of the star were obtained on March 6 and March 7, 1979, by the Einstein Observatory IPC, the IUE SWP and LWR cameras at low dispersion, three ground-based optical telescopes in …
A comparison of quasar absorption line systems with absorption by thegalactic halo.
Savage, B. D.; Jeske, N. A.
Milky Way halo and quasar absorption spectra contain a number of remarkable similarities which include mixed ion absorption, a general absence of excited fine structure levels with the possible exception of excited C II, similar column densities, and similar multicomponent line profiles. The extreme sensitivity of UV lines to small amounts of gas …
Interstellar absorption in the MgII resonance line K2 and H2 emissions.
Boehm-Vitense, E.
High-resolution (0.2 A) IUE spectra for the long wavelength range (1800-3000 A) have been studied. It is shown that narrow interstellar Mg II lines are seen in the center of the k2 and h2 emissions from nearby stars with large rotational velocities. For all observed stars, the radial velocity of the central k3 absorption component in the rest syst…
Ultraviolet spectra of dwarf solar neighbourhood stars. I.
Doyle, J. G.; Butler, C. J.; Byrne, P. B. +1 more
Short-wavelength IUE spectra of three nearby M-type dwarfs are presented. Two of these stars, Gliese 867 A and AU Mic, are active UV Ceti flare stars and their UV spectra exhibit strong emission lines, characteristic of active chromospheres. The third star, Gliese 825, is a low-activity flare star and its spectrum reveals no chromospheric lines. A…
Spectral energy distributions of hot stars with circumstellar dust.
Sitko, M. L.
Combined spectral energy distribution curves of six Ae/Be stars (BD+61 deg 154, AB Aur, V380 Ori, HD 259431, ZCMa, and BD+40 deg 4124), five peculiar shell stars (HD 31648, HD 45677, HD 50138, HD 163296, and HD 190073), and the peculiar central object in the Red Rectangle nebula (HD 44179), obtained with the IUE and a variety of ground-based optic…
R 81 : P CYG of the LMC.
Stahl, O.; Sterken, C.; Wolf, B. +1 more
Photometric UBV observations and spectroscopic high dispersion coude observations of the very luminous B2.5 eq supergiant R 81 of the LMC carried out between 1970 and 1980 at ESO, La Silla, are discussed. It is noted that the most prominent features of the visual spectrum are P Cygni profiles of the Balmer lines, which are thought to indicate a sh…
IUE detection of bursts of H LYα emission from Saturn
Moos, H. W.; Atreya, S. K.; Clarke, J. T. +1 more
An extended source of H Lyα emission (1,216 Å) from the vicinity of Saturn has been detected previously by a rocket-borne spectrometer1, the OAO-Copernicus satellite2, and the Pioneer 11 spacecraft3. During the rocket experiment, in which Saturn was observed on 15 March 1975, 700 R+/-50% of Lyα emission was detecte…