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A Reanalysis of the SWP-HI IUE Observations of Capella
Wood, Brian E.; Ayres, T. R.
We have reanalyzed the numerous high-resolution, far-ultraviolet observations of Capella made by the International Ultraviolet Explorer (IUE) in its 16 yr lifetime. Our purpose was to search for long-term profile variations in Capella's ultraviolet emission lines and to complement the analysis of Goddard High Resolution Spectrograph (GHRS) observa…
Resolution of Massive Compact Clusters in the 30 Doradus Periphery with the Hubble Space Telescope
Walborn, Nolan R.; Parker, Joel Wm.; White, Richard L. +2 more
Hubble Space Telescope Wide Field/Planetary Camera UBV images of three massive, compact multiple systems with the SNR 30 Dor B/NGC 2060 and 30 Dor C/NGC 2044 are discussed and illustrated. In two cases, WN+OB objects have been resolved into additional components to those previously known from ground-based observations, substantially reducing the l…
Photospheric, Circumstellar, and Interstellar Features of HE, C, O, and SI in the HST Spectra of Four Hot White Dwarf Stars
Fontaine, G.; Wesemael, F.; Vauclair, G. +11 more
This paper reports on the observations of four hot white dwarf stars with the spectrographs on the Hubble Space Telescope (HST). The higher resolving power and higher signal/noise, in comparison with IUE, reveals a very rich phenomomenology, including photospheric features from heavy elements, circumstellar features, and the first direct detection…
Solar wind plasma electron parameters based on aligned observations by ICE and ULYSSES
Scime, E. E.; Phillips, J. L.; Gosling, J. T. +1 more
During November-December 1991, the International Cometary Explorer and Ulysses spacecraft were aligned in solar longitude, with an angular offset as small as 1 deg and a radial offset of 3.8 to 4.0 AU. Both spacecraft carry spectrometers which measure the thermal and suprathermal solar wind electron distributions. During the alignment interval, bo…
White Dwarf Companions to Hyades F Stars
Bohm-Vitense, Erika
We have studied archival, short-wavelength, low resolution IUE spectra of Hyades F stars in an effort to detect white dwarf companions, which can give us information about the IMF for the Hyades duster Weidemann et al. pointed out that we have not detected the expected number of white dwarfs in the Hyades. They suspected that the missing white dwa…
Soft X-ray and ultraviolet observations of MRK 841: implications for the blue bump
Nandra, K.; Turner, T. J.; Fabian, A. C. +3 more
We present an analysis of an extended ROSAT observation of the Seyfert galaxy Mrk 841. The source is clearly variable on short time-scales with distinctive changes in the hardness ratio, indicating that more than one spectral component is present in the PSPC band. Spectral modelling of the soft X-ray data confirms this complex picture. The data sh…
Li I 6708 in normal A and F-type stars.
Castelli, F.; Gerbaldi, M.; Faraggiana, R.
The 6708 A Li region has been observed in a sample of unevolved stars of spectral type A-early F and the Li abundances have been determined by using the synthetic spectrum method. As the intensity of the Li I 6708 doublet decreases rapidly with increasing T_eff_ in these stars, we have to pay special attention to the list of lines present in the v…
Hubble Space Telescope Imaging of a Radio-quiet Galaxy at Redshift Z = 3.4
Giavalisco, M.; Macchetto, F. D.; Sparks, W. B. +1 more
We have observed with the Wide Field/Planetary Camera (WF/PC) on the Hubble Space Telescope (HST) a radio-quiet Lyα-emitting galaxy at redshift z = 3.428 (G2 below). The images probe the rest-frame UV light around 1250 A with an angular resolution of ~0.1", corresponding to 1.4 h_50_^-1^ kpc at redshift z = 3.4 (in this Letter we use q_0_ = 0 and …
Solar wind eddies and the heliospheric current sheet
McComas, D. J.; Goldstein, B. E.; Bame, S. J. +1 more
Ulysses has collected data between 1 and 5 AU during, and just following solar maximum, when the heliospheric current sheet (HCS) can be though of as reaching its maximum tilt and being subject to the maximum amount of turbulence in the solar wind. The Ulysses solar wind plasma instrument measures the vector velocity and can be used to estimate th…
Sources of shocks and compressions in the high-latitude solar wind: Ulysses
Hoeksema, J. T.; McComas, D. J.; Goldstein, B. E. +3 more
During its southern transit Ulysses sampled the solar wind to -80.2° latitude. Slow streamer belt wind was seen only equatorward of -35°, but its influence extended to much higher latitudes. Reverse shocks bounding the equatorial CIR were seen as far south as -58.2°. High-latitude compressional waves showed no clear correlation with that CIR. Spee…