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A photometric study of wide visual double stars with significant relative proper motion.
Sinachopoulos, D.
Photometric observations and uvby H-beta indices of 142 wide visual double stars are presented. Calibrations of the indices are used to derive MK class, color excess, absolute magnitude, effective temperature, and distance. The results are used to check candidates double stars for the Hipparcos mission for opticity.
Bl-Lacertae Objects as X-Ray Sources - the EXOSAT Observations
Maccagni, D.; Giommi, P.; Garilli, B. +2 more
Highly Ionized Species and Circumstellar Shells in B8--A1 Stars
Grady, C. A.; Bruhweiler, Frederick C.; Chiu, Weihsuen A.
The nature of the C IV and Si IV absorption seen in the spectra of apparently normal late-type B and early-type A stars located within 200 pc of the sun was investigated by examining a total of 93 archival IUE spectra of 41 stars. In three of these objects, variable or asymmetric C IV profiles indicate that the absorption features have a stellar o…
Properties of the components of the UZ Librae system.
Grewing, M.; Garrido, R.; Bianchi, L.
A reanalysis is conducted of the available photometric and spectroscopic data for the K-giant UZ Librae, including recent uvby photometry. The rotational period thus derived is close to, but not identical with the orbital period. Attention is given to UV spectra taken at different orbital/rotational phases. It is concluded that the overall propert…
The Ionization Structure of Planetary Nebulae. IX. NGC 1535
Barker, Timothy
The ionization structure of planetary nebula NGC 1535 was investigated using spectrophotometric observations of emission-line intensities over the spectral range 1400-7200 A, which were carried out in five positions in this nebula. The results obtained on the ionic abundances of He, O, N, Ne, C, and Ar in NGC 1535 suggest that it is a planetary ne…
The Chromosphere of Beta Cassiopeiae
Teays, Terry J.; Schmidt, Edward G.; Fracassini, Massimo +1 more
High-resolution, long-wavelength IUE observations and ground-based photometry of the Delta Scuti star Beta Cas is reported. The ground-based observations were used together with previous results of Antonello et al. (1986) to ensure that the IUE observations were correctly phased relative to the photometric variation. Fluxes for the emission core o…
Phase variations of 88 Herculis : do the UV observations confirm a connection between these variations and the changes of the phospheric parameters of the underlying star ?
Zorec, J.; Hoeflich, P.; Divan, L.
It is shown that the observed far-UV flux variation of 88 Herculis from 1976 to 1979 is lower than previously reported. The variation from 1979 to 1983 is difficult to confirm. The remaining flux changes cannot be attributed to changes in the stellar luminosity of the star. Furthermore, the constancies of the size and of the position-wavelength of…
MG II Line Profiles of the Mira S Carinae
Brown, Alexander; Bookbinder, Jay A.; Brugel, Edward W.
A series of high-dispersion IUE observations obtained to investigate the evolution of the shock structure of the Mira variable S Carinae have produced (despite limited phase coverage) a set of five exceptionally interesting spectra of the Mg II h and k lines. The two primary findings of these observations are (1) there is significant emission from…
Evidence for near-surface breezes on Comet P/Halley
Keller, H. U.; Thomas, N.
Halley Multicolor Camera (HMC) images taken of the nucleus of Comet P/Halley and its environment from on board ESA's spacecraft, Giotto, provide substantial evidence for flow of dust particles almost parallel to the surface at small cometocentric distances. This evidence is summarized and discussed with reference to other spacecraft experiments, g…
In situ exploration of the dusty coma of comet P/Halley at Giotto's encounter: Flux rates and time profiles from 10-19kg To 10-5kg
Green, S. F.; Kissel, J.; McDonnell, J. A. M. +4 more
Flux rates and time profiles from the Giotto DIDSY and PIA experiments are presented in the light of more refined data analysis and increased data coverage. The methods of data analysis for both experiments are explained, together with the relevant behaviour of their in-flight performance. A mass distribution from 237 000km to 11 500km from comet …