Search Publications

IUE observation of strong UV absorption in the spectrum of the C2 white dwarf ion of LP 145-141.

Koester, D.; Weidemann, V.; Vauclair, G.

An absorption feature of exceptional strength has been observed by IUE around 1900 Å in the spectrum of the cool (7500 K) degenerate "λ467O" or "C₂" star LP 145-141. Molecule formation is shown to be favoured in helium-rich, high pressure white dwarf atmospheres, with CO, C₂ or O₂ dominant, depending on the He/C an…

UV spectrograms of T Tau stars.

Wolf, B.; Mundt, R.; Appenzeller, I. +2 more

The IUE satellite has been used to observe the ultraviolet spectra (1200-3200 A, 6A resolution) of the T Tauri stars DR Tauri, CoD-35 deg 10525, and AS205. In addition, earlier IUE spectrograms of the T Tauri star S CrA were rereduced using a more effective procedure. The new IUE observations were supplemented by simultaneous (or nearly simultaneo…

IUE spectra of the jet and the nucleus of M 87.

Tarenghi, M.; Perola, G. C.

IUE spectra from 1300 to 3000 A of the jet and the nucleus of M87 are presented. The flux detected with the 10 x 20 arcsec aperture positioned on the jet is consistent with the extrapolation of the optical power law spectrum of the bright complex of knots A plus J plus B, plus a contribution of diffuse light from M87. The spectrum of the nucleus d…

X-ray and ultraviolet spectroscopy of CYG X-1 = HDE 226868.

White, N. E.; Kondo, Y.; McCluskey, G. E. +5 more

Observations of Cygnus X-1 with the solid-state spectrometer on the Einstein Observatory are presented. The X-ray spectra of two intensity dips viewed near superior conjunction did not exhibit increased photoelectric absorption. Rather, the data support a model in which an increase in the electron-scattering optical depth modifies both the observe…

Observations of the quiescent corona, transition region, and chromosphere in the dMe flare star Proxima Centauri.

Linsky, J. L.; Haisch, B. M.

An upper limit to the global SO₂ abundance on Io

Owen, T.; Caldwell, J.; Butterworth, P. S. +3 more

Gaseous sulphur dioxide has been detected on Io by the Voyager 1 IRIS experimemt¹. It was associated with a major volcanic plume, and it was observable only because the local underlying surface was warm enough (>210K) to be detected near 7 µm, and thereby reveal the gas in absorption. The estimated column abundance of SO₂ …

Ultraviolet observations of WZ SGE in outburst.

Fabian, A. C.; Pringle, J. E.; Stickland, D. J. +1 more

The paper describes low and high-resolution UV spectroscopic observations of the recurrent nova WZ Sge obtained during its December 1978 outburst. The observations were made during outburst with the IUE satellite. Low-resolution images obtained on December 14 and 24 are discussed. The continuum on both days may be fitted by a power law or an optic…

Ultraviolet spectra of planetary nebulae. II. The young PN IC 4997.

Flower, D. R.

Observations of the planetary nebula IC 4997 made with the International Ultraviolet Explorer satellite are analyzed in conjunction with visual photoelectric observations. The extinction to the nebula and the electron temperature and density are deduced from the relative intensities of lines emitted by O(+) and O(2+) ions. The relative abundance o…

IUE low-dispersion spectra of four luminous stars in symmetric nebulae.

Johnson, H. M.

The stars and nebulae are HD 56925 in NGC 2359, + 60 deg 2522 in NGC 7635, AG Car in its nebula, and 209 BAC in M1-67. A discussion of known properties of these systems precedes the IUE data, which are tabulated with types and identifications of significant line features and velocities of ultraviolet-displaced absorption features. Weaver et al.'s …

Infrared photometry of HDE 226868 (Cyg X-1) from 2.3 to 10 MU : mass loss rate.

Persi, P.; Ferrari-Toniolo, M.; Grasdalen, G. L. +1 more

Infrared photometry between 2.3 and 10 microns, shows an ionized gaseous envelope surrounding the supergiant OB star HDE 226868, the optical counterpart of the X-ray binary system Cyg X-1. The mean extent of the envelope at 10 microns is approximately 1.3 R (asterisk). The mass loss rate of HDE 226868 derived from 10 microns ff + bf emission flux,…