Search Publications
The Detection of Photospheric X-Ray Pulsations from PG 1159-035 with EXOSAT
Winget, D. E.; Barstow, M. A.; Holberg, J. B. +1 more
The detection of soft X-ray pulsations from the hot, helium-rich, degenerate object, PG 1159-035 is reported. These observations, obtained with the Low Energy experiment on EXOSAT, show the presence of large-amplitude soft X-ray (44-150 A) pulsations analogous to several of the low-amplitude, nonradial, g-mode pulsations which are observed in the …
EXOSAT measurements of the quiescent X-ray spectrum of the burster 2S1636-536 : evidence for Comptonization in a hot corona.
King, A. R.; Courvoisier, T. J. -L.; Turner, M. J. L. +1 more
Measurement of the X-ray spectrum of the quiescent flux from the burster 2S 1636-536 with EXOSAT on 1983 July 17 - 18 gave as a best-fitting model a power law with a high-energy cut-off. The flux (2 - 10 keV) was seen to increase from 1.6×10-9erg cm-2s-1 to 2.5×10-9erg cm-2s-1 durin…
Ultraviolet Spectrophotometry of Three LINERs
Keel, W. C.; Goodrich, R. W.
Three galaxies known to be LINERs were observed spectroscopically in the ultraviolet in an attempt to detect the presumed nonthermal continuum source thought to be the source of photoionization in the nuclei. NGC 4501 was found to be too faint for study with the IUE spectrographs, while NGC 5005 had an extended ultraviolet light profile. Compariso…
Ultraviolet Observations of V471 Tauri: Evidence for a Nova-like Outburst?
Bruhweiler, F. C.; Sion, E. M.
A search for accretion of wind-flare material onto the white dwarf in V471 Tauri has unexpected by revealed what appears to be shortward-shifted absorption, centered on two distinct velocities, near heliocentric velocities of -300 and -590 km/s in the line of sight toward V471 Tauri. The possibility that these features are due to instrumental effe…
Trajectory Determinations and Collection of Micrometeoroids on the Space Station
Doyle, J. G.; Butler, C. J.; Byrne, P. B.
We report on a search for flaring and BY Draconis type variability on the M-dwarf Balmer emission line star, Gliese 867 B. The time-averaged flare energy in the Johnson U-band is similar to that measured in 1977 and 1978. A typical wave4ike variation of 0.15 magnitudes, seemingly due to rotational modulation of large spotted areas, was observed in…
The spectra shape and variability of the blazar 3C 446.
Gear, W. K.; Robson, E. I.; McHardy, I. M. +5 more
The radio to X-ray spectrum and variability of 3C 446 are discussed, and it is shown that the entire infrared-ultraviolet wavelength region exhibits strongly correlated variations, with the infrared and optical fluxes varying together on a time-scale of weeks or less. The variations in spectral shape which occur in the submillimeter to optical wav…
High-velocity interstellar gas in the line of sight to the Wolf-Rayet star HD 50896
Fesen, R. A.; Nichols-Bohlin, J.
A large, high-velocity interstellar shell has been discovered in the direction of the Wolf-Rayet star HD 50896. Two distinct high-velocity interstellar components at approximately -80 and -125 km s-1 were detected in the low-ionization resonance lines of IUE spectra for HD 50896 and 11 neighboring field stars, precluding the possibility…
The Strong UV Source in the Active E Galaxy NGC 4552
Thuan, T. X.; Puschell, J. J.; Oconnell, R. W.
1200-3200 A IUE spectra of the nucleus of NGC 4552 (M89) were obtained in order to investigate the nature of the strong 10 micron source in this Galaxy. There is a strong, extended UV source in NGC 4552 which has a spatial distribution nearly identical with that at optical wavelengths and is undoubedly stellar in origin. Its properties are consist…
Low-resolution IUE observations of four unreddened, 11th magnitude B stars at high galactic latitudes.
Tobin, W.
Low-resolution IUE spectra are presented for the four faint, unreddened, high-latitude, mid-B stars Feige 40 (≡FB 72), H.O. +23°B, H.O. +41°B (≡SS II 135) and PB 166. By comparison with stars in the Heck et al. atlas, the spectra are like those of normal disc stars of Population I metallicity. This suggests that the programme stars are massive, lu…
Far-Ultraviolet Fluorescence of Carbon Monoxide in the Red Giant Arcturus. II. Analysis of High-Dispersion IUE Spectra
Ayres, T. R.
Faint, diffuse emissions near 1380 A in deeply exposed IUE spectrograms of the red giant Arcturus very likely are associated with bands of the A-X fourth-positive system of carbon monoxide, fluoresced by multiplet UV2 of neutral oxygen near 1305 A. Numerical simulations indicate that the strength of the CO bands is exceedingly sensitive, in the be…