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Effective temperatures and radii of Large Magellanic Cloud supergiants.
Nandy, K.; Willis, A. J.; Wilson, R. +3 more
The absolute fluxes and flux distributions of 25 Large Magellanic Cloud supergiants are compared to those of similar galactic stars. The effective temperatures and radii of the LMC stars are found by comparison with models. No significant difference between the LMC and our Galaxy is found.
Molecules in celestial objects - III. Study of CO in interstellar diffuse clouds.
Krishna Swamy, K. S.; Tarafdar, S. P.
The absorption lines corresponding to the A-X transition of CO have been looked for in the IUE spectra of 14 stars with varying values of the colour excess, E(B-V) and found to be present in the spectra of nine stars with E(B-V) at least 0.28. The column density of CO has been determined towards these nine stars and its upper limit towards the res…
Mira B.
Stickland, D. J.; Cassatella, A.; Ponz, D.
A high resolution IUE spectrum of Mira taken at the time of the 1980 maximum shows sharp emission features from the M star and broad ones attributable to a large volume of gas around the hot companion. Some information on the emission from the vicinity of Mira B is available from line widths and ratios.
Mass loss from Be stars derived from UV spectra.
de Freitas Pacheco, J. A.
The present investigation considers the interpretation of UV line profiles of some Be stars obtained with the International Ultraviolet Explorer (IUE) spacecraft, giving particular attention to Pi Aqr. The mass-loss rates are estimated using the Sobolev approximation and assuming that the observed asymmetric UV lines are formed in an expanding env…
The physical state of the gas towards HD 93206.
Welsh, B. Y.; Thomas, C. K.
A description is presented of a high resolution study of the ultraviolet spectrum of the star HD 93206 using the IUE satellite. This star is among those observed at optical wavelengths by Walborn and Hesser (1975) and belongs to the Cr 228 association which lies approximately 15 arcmin south of the peculiar object of Eta Car. This star is part of …
Infrared, optical and ultraviolet observations of TT Ari.
Jameson, R. F.; King, A. R.; Sherrington, M. R.
B, V, J and K light curves together with the IUE ultraviolet spectrum of the cataclysmic variable TT Arietis are presented. The interpretation of these data leads to a system distance of 100 pc and outer disc temperature of 11,000-12,500 K.
Ultraviolet spectra of planetary nebulae. IX. High-dispersion observations of NGC 7662.
Seaton, M. J.; Flower, D. R.; Penn, C. J.
High-dispersion IUE spectra of NGC 7662 have been obtained with exposure times optimized for measurement of the relative strengths of the components of: CIV lambda-lambda 1548, 1551; the forbidden line CIII lambda-lambda 1907, 1909 and the forbidden line Ne IV lambda-lambda 2422, 2424. The CIV ratio (lambda 1548)/(lambda 1551) is expected to be 2.…
Ultraviolet spectra of planetary nebulae. VIII. The C/O abundance ratio in the ring nebula.
Flower, D. R.
The Ring nebula (NGC 6720) has been observed with the International Ultraviolet Explorer satellite. Measurements of line intensities at a position on the ring, offset from the central star, lead to a value of the abundance ratio C/O approximately 1.2, a result which is insensitive to the adopted value of the electron temperature in the nebula.
Ultraviolet spectroscopy of phi Per.
Kitchin, C. R.
Ultraviolet observations at high dispersion of Phi Persei obtained on the IUE satellite are described. The interstellar lines are separated from the stellar and shell lines, and all the lines are identified. The velocity of the interstellar medium in the direction of Phi Per is estimated to be about 34 km/sec. A model of the system based on the ul…
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…