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Distribution of hot stars and hydrogen in the Large Magellanic Cloud
Page, T.; Carruthers, G. R.
Far-UV brightness distribution data for the face of the Large Magellanic Cloud (LMC) are derived from calibrated electrographic imagery in the 1050-1600 and 1250-1600 A ranges, and far-UV fluxes for individual hot-star groupings in the LMC are compared with H-alpha measurements and with a 21-cm survey. It is found that large clouds of interstellar…
Ultraviolet observations of the Io torus from the IUE observatory
Moos, H. W.; Clarke, J. T.
The short wavelength spectrograph on the International Ultraviolet Explorer (IUE) has been used to obtain 11 A resolution spectra of the Io torus from 1175-1950 A. The four spectra, obtained in the springs of 1979 and 1980, show emissions (about 40R) of S II A1256A and S III A1199A. An unidentified feature is also present at 1729 A; a tentative id…
Far-ultraviolet fluorenscence of carbon monoxide in the red giant Arcturus.
Moos, H. W.; Linsky, J. L.; Ayres, T. R.
Evidence is presented that many of the weak features observed with International Ultraviolet Explorer (IUE) in the far-ultraviolet (1150-2000 A) spectrum of the archetype red giant Arcturus (K2 III) are A-X fourth positive bands of carbon monoxide excited by chromospheric emissions of O I, C I, and H I. The appearance of fluorescent CO bands near …
Observations of strong ultraviolet absorptions in the spectrum of theDC white dwarf LDS 678 B.
Wegner, G.
Evidence from spectroscopic observations that LDS 678 B has strong ultraviolet lines of neutral carbon in its spectrum is presented. The spectra are found to contain strong lines of C I in the ultraviolet and weak He I lines in the visible. The appearance of the star's spectrum and published photometry are consistent with its having an effective t…
The 1979-1980 eclipse of ZET Aur. I. The circumstellar envelope.
Chapman, R. D.
A model of the K-star wind far from the K star, and its interaction with the B star, has been derived from a study of Mg(+) and C(+++) resonance lines in the spectrum of Zeta Aurigae during 1979 and 1980. A mass loss rate from the K star of 2 x 10 to the -8th solar masses/year is suggested by the data; the rate of accretion of the K supergiant's m…
Ultraviolet extinction curves derived from IUE data.
Joseph, C. L.; Snow, T. P., Jr.; Seab, C. G.
Data from the International Ultraviolet Explorer (IUE) have been used to derive extinction curves for several stars chosen because of unusual diffuse band strength or location within dense clouds. Both the strength and position of the 2200 A extinction maximum were assessed, as well as the level of extinction in the far-ultraviolet. A variety of c…
BE UMa (PG 1155+492) : a unique cataclysmic-variable-like object.
Spinrad, H.; Green, R. F.; Liebert, J. +2 more
The variable spectrum of BE Ursae Majoris, which is similar to that of the cataclysmic variables (CVs), shows (1) an emission-line spectrum with the high-excitation CN 4650 A blend as the strongest optical feature, weaker H and He lines, and a strong Balmer jump, and (2) an absorption spectrum dominated by He. Although the object shows no evidence…
The ultraviolet interstellar extinction curve in the Pleiades.
Bohlin, R. C.; Witt, A. N.; Stecher, T. P.
The wavelength dependence of ultraviolet extinction in the Pleiades dust clouds has been determined from IUE observations of HD 23512, the brightest heavily reddened member of the Pleiades cluster. There is evidence for an anomalously weak absorption bump at 2200 A, followed by an extinction rise in the far ultraviolet with an essentially normal s…
Quasi-simultaneous observations of BL Lac object MRK 501 in X-ray, UV, visible, IR, and radio frequencies.
Kondo, Y.; Yee, H. K. C.; Worrall, D. M. +8 more
Observations in the X-ray, UV, visible, IR and radio regions of the BL Lac object Mrk 501 made over the course of two months are reported. The measurements were made with the A2 experiment on HEAO 1 (X-ray), the SWP and LWR cameras on IUE (UV), the 5-m Hale telescope (visible), the 2.5-m telescope at Mount Wilson (IR), the NRAO 92-m radio telescop…
The optical and ultraviolet spectra of the high excitation planetary nebula, CD -23 12238 = ME 2-1.
Czyzak, S. J.; Keyes, C. D.; Aller, L. H.
Planetary nebula are now recognized as a penultimate stage in the evolution of many stars. Me 2-1 offers advantages meriting a detailed analysis. A description is presented of measurements regarding this object which have been conducted with a photoelectric scanner and a 3 m telescope Cassegrain image tube scanner. The chemical composition of Me 2…