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Shock-heated gas in the I Per OB association.
Nandy, K.; McLachlan, A.
In response to a suggestion by Phillips & Gondhalekar (1981) that hotgas is receding from the I Per OB association with a velocity of ≡30 km s-1, the authors have examined the IUE high-dispersion spectra of stars in the association for blueshifted lines of interstellar C IV, Si IV and Al III. As a result, the high-velocity ions are …
The identification of H 2311+77 with HD 220140, a probable RS CVn star.
White, N. E.; Giommi, P.; Pravdo, S. H.
H2311+77, one of the bright soft X-ray sources in the sky originally detected with HEAO 1, has been identified in an EXOSAT imaging observation with a 7.7-mag late-type star, HD 220140. The X-ray luminosity and the optical characteristics of this star indicate that it is probably an RS CVn binary system.
IUE high-resolution observations of Mira B.
Reimers, D.; Stickland, D. J.; Cassatella, A. +2 more
A high-resolution spectrum of Mira obtained with IUE on 1983 July 7 confirms the presence of broad emission lines with typical half base widths of ≅300 to roughly 1000 km s-1. No narrow emission lines are detected. The observed broad lines cannot originate from the extended atmosphere of the cool giant variable. The authors show in part…
IRAS observations of MKN 501 with quasi-simultaneous observations at radio, near-infrared and ultraviolet wavelengths.
Di Cocco, G.; Coe, M. J.; Spinoglio, L. +9 more
The authors present quasi-simultaneous observations at radio, far-infrared, near-infrared and ultraviolet wavelengths of the BL Lac object MKN 501. Specifically, they have observed the source with the IRAS satellite, and they show that the best power-law fit to the 12 to 100 µm data gives a slope of index α = 0.55±0.1. They show that the com…
A survey of MG II H and K emission in near-solar-type stars.
Doherty, L. R.
IUE measurements of Mg II h and k emission fluxes are presented for 30 F and G stars that are on or near the main sequence and compared with Wilson's measurements of the Ca II H and K fluxes in these stars. The survey includes a large proportion of stars with very low chromospheric activity as well as 111 Tau, χ1Ori and other examples o…
X-ray emission from the cataclysmic variable PG 0834+488.
Cook, M. C.
A 5-hr observation of PG0834+488 using the EXOSAT X-ray observatory has resulted in its detection as an X-ray source. The light curve shows marginal evidence for variability but no coherent periodicities were found. The X-ray spectrum was hard, with a photon index of ≡1.36, and the low-energy absorption implied a low column density NH ≡…
HR 5637 : the unveiling of a binary.
Cottrell, P. L.; Ake, T. B., III; Noordanus, B.
HR 5637, previously classified as G1/3 Ib/II but considered composite by Bidelman and MacConnell, has been examined both photometrically and spectroscopically. The spectroscopic observations spanned the wavelength interval 1000-7000 A. Using these data in various combinations, the star is shown to be a binary with components of G2-5Ib and B8 V, wi…
Observations of Comet Crommelin. V - Anomalous hydrogen source
Wallis, M. K.; Carey, W. C.
Lyman-alpha intensities measured by IUE at various positions in the coma of Comet Crommelin are interpreted on the basis of H2O model calculations. However, the H-production on dates in March and April 1984 was significantly higher than implied by OH measurements by IUE and from the ground. Simultaneous data from the two apertures on March 30 excl…
Observations of Comet Crommelin. IV - Upper limit on the optical depth in the coma at ultraviolet wavelengths
Evans, A.; Zarnecki, J. C.; Bode, M. F. +2 more
The bright (V = 9.1) star SAO 152362 was observed with the long-wavelength (LWP) camera of the IUE satellite before and during a close approach by Comet Crommelin. No significant change in the ultraviolet spectrum of the star occurred during the encounter and an upper limit is set on the optical depth of the dust in the coma of the comet.
Detailed observations of NGC 4151 with the IUE - III. Variability of the strong emission lines from 1978 February to 1980 May.
Tanzi, E. G.; Tarenghi, M.; Perola, G. C. +8 more
Observations of the variability of the three strong ultraviolet emission lines in the Seyfert galaxy NGC 4151 (C IV, C III] and Mg II) are used to study the structure of the broad line region and the nuclear energy source of this active galaxy. Data on the line profile variations further permit the kinematic mapping of the broad line region throug…