view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Some spectrophotometric observations of the WoIf-Rayet stars HD 192103 and HD 192163. Underhill, Anne B. Abstract The following claims regarding Wolf-Rayet stars may be found in the literature: (I) that all Wolf-Rayet stars are binaries, (2) that the color temperatures of Wolf-Rayet stars determined spectrophotometrically over the range N3900 to N5ooo are of the order of 12,0000, and (3) that no N lines are to be found in WC spectra and no o lines in WN spectra. These conclusions obscure the relationship of the Wolf-Rayet stars to the rest of the stellar population. Grating spectrograms at i6A/mm have been obtained of HD 192103 and HD 192163 covering the range N3100 to N4500. This material was supplemented by prismatic spectrograms of moderate dispersion (~oA/mm at H7) covering the range N4000 to N68oo. The following comments may be made: (I) The radial velocity of each star was obtained on 4 nights in 1957-58, and it does not vary by an amount 1n excess of 30 km/sec. The scatter among the results can be entirely accounted for by the random errors of measurement. No absorption features attributable to an O or B type companion are visible in the spectrum of HD 192103 or of HD 192163. Thus these stars do not have companions of absolute magnitude brighter than - I. A fainter companion could not readily be detected. (2) There are many weak emission features 1n both spectra in addition to the well-known strong lines. Thus both spectra rarely dip to the continuum. The continuous spectrum that was finally derived after studying tracings from N3100 to N68oo is very like that of an 0 star. It does not look like that of a star which has a color temperature of 12,0000 and there is no Balmer jump in absorption or emission. Slitless spectra will be required to obtain meaningful quantitative measurements of the continuous spectrum. (3) A list of wave lengths has been compiled from measurements made on microphotometer tracings. This list is more comprehensive than previous lists and gives evidence that Niii, Niv and Nv occur in WC spectra, the clearest nitrogen line being Niii N6455. The spectra of Oiii, Oiv and Ov are present in the WN spectrum, particularly in the ultraviolet. There is an unmistakable Ov emission occurring as a weak feature between Heii N541 I and about N5470. Dominion A strophysical Observatory, Royal Oak, B. C., Canada Publication: The Astronomical Journal Pub Date: March 1959 DOI: 10.1086/107867 Bibcode: 1959AJ.....64...55U full text sources ADS |
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Aug 1, 1960
P Th Oosterhoff 
