Search Publications
Physical conditions in the UV line emitting region of supernova 1979cin NGC 4321.
Panagia, N.; Fransson, C.; Reimers, D. +5 more
Ultraviolet observations of SN 1979c are used to derive the physical conditions in the line-forming regions. The emission lines have asymmetric profiles and large expansion velocities and are therefore formed in a narrow shell close to the photosphere having a constant velocity. The most likely mechanism for the excitation of these lines is photoi…
A study of the Herbig Ae-type stars UX ORI and CD -44 3318 based on IUE spectra, and on visual and infrared photometry.
The, P. S.; Tjin A Djie, H. R. E.; Remijn, L.
The spectral classifications of the two Herbig Ae stars UX Ori and CD-44 deg 3318 are reconsidered. The far-UV spectra of the stars are both similar to those of early A-type supergiants; however, the spectral types A2 III and A0-1 III are here derived for the respective stars based on continuum shapes, absorption features, and distance arguments. …
Ultraviolet, optical and infrared observations of the Wolf-Rayet contact-eclipsing binary CQ Cephei.
Bromage, G. E.; Howarth, I. D.; Willis, A. J. +5 more
IUE spectra of CQ Cep covering virtually all binary phases are analyzed, together with new UBVJKL photometry and remeasurements of radial velocities from archived optical spectra. The high resolution UV interstellar line spectrum strongly supports CQ Cep's membership in the Cep OB1 association. Continuum light curves in 15 wavebands, from 0.13 to …
Inflow of halo gas from the direction of the galactic North Pole.
Savage, B. D.; de Boer, K. S.
A far-UV echelle spectrum has been obtained of the UV-bright star vZ1128 in the globular cluster M3. This cluster lies in a direction 11° off the galactic North Pole at a distance of about 10 kpc. Only the usually strong interstellar lines are recognizable in the faint spectrum, and they show absorption at velocities from near +40 km s-1
The ultraviolet (IUE) spectra of the lambda Bootis stars.
Heck, A.; Jaschek, M.; Jaschek, C. +4 more
Ultraviolet spectra of several λ Boo stars and λ Boo candidates have been obtained with the IUE satellite in low- and in high-resolution. It is possible to discriminate the λ Boo stars from the normal A stars on low resolution spectra by their strong absorption features at λλ1600, 1657(C I), 1931(C I), and 3040 Å. The λ1600 feature, about 80 Å wid…
Variable blue supergiants in the Large Magellanic cloud : R 84, R 85 and R 99.
Stahl, O.; Leitherer, C.; Zickgraf, F. -J. +3 more
During a search for luminous blue variables in the LMC the three emission-line stars R 84 (OIafpe), R 85 (B5Iae), and R 99 (OBf:pe) have been found to show significant brightness and colour variations. Photometric and spectroscopic data from the UV to the IR have been used to discuss the nature of these variables. It is argued that they are closel…
The orbital parameters and the X-ray pulsation of VELA X-1 (4U 0900-40).
van der Klis, M.; Bonnet-Bidaud, J. M.
Results are presented of an analysis of 83 d of 2 - 12 keV X-ray observations of Vela X-1 (4U 0900-40) obtained with the ESA COS-B satellite. Combining the present determinations of the orbital epoch from pulse timing with those obtained with other satellites, the data are found to be consistent with an increase of the orbital period at a rate (P/…
Bolometric corrections for peculiar B-type stars.
Lanz, T.
Semi-empirical bolometric corrections are estimated for 25 peculiar stars and 13 comparison stars from IUE low dispersion spectrum and from theoretical fluxes best fitting the Geneva colour indices. When corrected for reddening, the relation BC vs. (B2-G)0 for main-sequence stars matches fairly well the theoretical relation computed by …
Nebular and interstellar absorption lines in planetary nebulae : the case of NGC 6543.
Pottasch, S. R.; Pwa, T. H.; Mo, J. E.
Using high resolution IUE spectra it is possible to separate the narrow absorption lines due to the interstellar material and the nebular matter. The analysis of nebular absorption lines has three advantages. First the column densities of ions different from those observed in emission can be determined. The abundance of the elements are then readi…
The 1200-3200 A spectra of Seyfert I galaxies : MK 304, NGC 7603, MCG8-11-11, ESO 12-G 21 and NGC 1566.
Clavel, J.; Joly, M.
The 5 Seyfert I galaxies MK 304, NGC 7603, MCG 8-11-11, ESO 12-G 21, and NGC 1566 have been observed with IUE (1200 - 3200 Å). Their UV spectrum is rich in emission lines. A steep rise of the continuum toward shorter wavelengths is observed below ≡2000 Å in 4 of these objects; this excess is interpreted as thermal emission from an accretion disk. …