Search Publications
The chromosphere and corona of Procyon (Alf CMi,F5IV-V).
Jordan, C.; Brown, A.
Observations are reported of Procyon (alpha CMi), an F5 IV-V star, obtained with the IUE satellite at low and high spectral resolutions as part of a program to study the chromospheres and coronae in late-type stars. Methods for analyzing the fluxes and linewidths of alpha CMi and other near main sequence stars are presented, and applied to alpha C…
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…
High-velocity gas associated with the supernova remnant S 147.
Gondhalekar, P. M.; Blades, J. C.; Phillips, A. P.
The star HD 36665 (Ble), which lies behind the old supernova remnant S147, has been observed with the IUE satellite. High-velocity interstellar absorption components of Fe II, Mg I, Mg II, Al II, C II and Si II were detected which originate in gas associated with the remnant. No such high-velocity lines were observed in the IUE spectrum of HD 4011…
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…
The X-ray modulation of CYG X-3.
van der Klis, M.; Bonnet-Bidaud, J. M.
Results of three 40d COS-B X-rays observations of Cyg X-3 are presented. The shape of the light curve, although variable from cycle to cycle, is generally very stable when averaged over many cycles. During one four-week period, however, a different mean light curve was observed. It is shown that the correlated behavior of amplitude, average level,…
Long term X-ray observations of SMC X-1 including a turn-on.
van der Klis, M.; Bonnet-Bidaud, J. M.
A 38 d COS-B observation of SMC X-1 in the 2-12 keV band is presented, the observation including a turn-on of this source. The data are analyzed within the framework of the stellar wind accretion model, both from the point of view of the expected accretion rate and of the absorption of X-rays in the wind. It is noted that neither the high state lu…
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…