Search Publications
Missions
Journals
Publication Years
I.U.E. high resolution observations of hot stars emitting coronal x-rays
Bianchi, Luciana
The far UV resonance lines of a sample of 21 early-type stars, which were observed in the soft X-Ray band with the Einstein satellite, are examined using I.U.E. high resolution spectra to search for possible correlation between the X-Ray coronal emission and far UV spectral properties. In particular, those quantities that can give information on t…
Observational aspects of chromospheres and coronae in hot stars
Stalio, R.
With the advent of high resolution space observations with high sensitivity, stellar atmospheric research has entered a new phase of rapid development. All stars, and especially hot stars, are now recognized to have atmospheric characteristics that were not suspected before. All hot stars that we can observe with sufficient accuracy show chromosph…
Cool luminous stars
Linsky, J. L.
A broad theme emerging from IUE and Einstein observations of cool stars is that magnetic fields control the structure and energy balance of the outer atmospheres of these stars. I summarize the phenomena associated with magnetic fields in the Sun and show that similar phenomena occur in cool luminous stars. High dispersion spectra are providing un…
Second COS-B catalogue of high-energy gamma-ray sources.
Bignami, G. F.; Hermsen, W.; Masnou, J. L. +11 more
A list of 25 high-energy (greater than 100 MeV) gamma-ray sources detected by COS B is presented. Only four sources are identified with well-known objects. Of the remaining sources, 20 are at low galactic latitude, and they may represent a new galactic population. Their luminosity is estimated to be in the range of (0.4-5) x 10 to the 36th ergs/se…
Ultraviolet absorption by interstellar gas at large distances from the galactic plane.
Savage, B. D.; de Boer, K. S.
Eighteen high-dispersion IUE spectra of six stars in the Large Magellanic Cloud, three stars in the Small Magellanic Cloud, and two foreground stars were analyzed. Fourteen spectra cover the wavelengths 1150-2000 A, and four cover 1900-3200 A; the velocity resolution is about 25 km/s. All the Magellanic Cloud spectra exhibit very strong interstell…
Mass loss from very luminous OB stars and the CYG superbubble.
Churchwell, E.; Abbott, D. C.; Bieging, J. H.
A description is presented of radio continuum measurements of mass loss from OB stars made at a wavelength of 6 cm with the Very Large Array (VLA). Five of the six most luminous members of the stellar association Cyg OB2 were detected. The considered investigation concentrates on the most luminous stars known in the Galaxy. The stars were selected…
Outer atmospheres of cool stars. IX. A survey of ultraviolet emission from F-K dwarfs and giants with the IUE.
Linsky, J. L.; Ayres, T. R.; Marstad, N. C.
Low-dispersion ultraviolet spectra (1150-2000 A) of a representative sample of cool stars, including dwarfs and giants of spectral types F-K, obtained with the IUE, are examined. The observation and the absolute calibration procedures are described. Correlation diagrams are constructed that compare chromospheric and transition-region emission line…
The FK COM stars.
Stencel, R. E.; Bopp, B. W.
The paper presents IUE observations of three very rapidly rotating G-K giants (v sin i = 100 km/s). The UV spectra show strong chromospheric and transition region emission lines similar to (and in excess of) the RS CVn binaries. These stars show no evidence for radial velocity variations in excess of plus or minus 3 to plus or minus 20 km/s, argui…
The type II SN 1979c in M 100 and the distance to the Virgo cluster.
Wills, B. J.; Branch, D.; Falk, S. W. +3 more
Intensity calibrated optical spectrophotometric observations of supernova 1979c in M100 were obtained between April 22, 1979 and November 24, 1979. The time development of the spectrum appears typical for type II events, except perhaps that the H-alpha feature never appears in P Cygni form. Synthetic spectra computed using a blackbody photosphere …
Mass-loss rates for 21 Wolf-rayet stars.
Willis, A. J.; Smith, L. J.; Barlow, M. J.
Mass-loss rates have been derived for 21 WR stars encompassing most subtypes in the WN and WC sequences, from measurements of their infrared free-free fluxes. The resultant mass-loss rates show a range of only a factor of 4. WC stars generally have larger mass-loss rates than WN stars, the mean rates being M(WC) = 4.1 x 10 to the -5th solar mass/y…