Abstract
view Abstract Citations (38) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The Wolf-Rayet Spectroscopic Binaries HD 186943, HD 193928, and HD 211853 Hiltner, W. A. Abstract These three Woif-Rayet stars have been investigated as spectroscopic binaries. For HD 186943, spectral type WN5, hydrogen~absorption lines were measured, as well as the emis- sion bands He ii 4686, N v 4603, and Nv 4619. The absorption lines belong to the early B-type com- panion. The following elements have been derived: P = 9.550 days, e = 0.0 (assumed), KWR (He ii 4686) = 235 km/sec, KB = 65 km/sec, MWR sin3 i = 5.8 0, and MB ~j~3 ~ = 21.0 0. There are pro- nounced differences in the gamma-velocities of the three emission bands, none agreeing with the gamma- velocity for the hydrogen absorption. The amplitude of the velocity-curve for N v 4603 and N v 4619 is smaller than that for He ii 4686. Also, the N v velocity-curve shows a phase shift of 0.8 day with re- spect to He ii 4686. The spectral type of HD 193928 is about WN6. Only the Woif-Rayet component of the system is observable. The following elements have been derived from 30 McDonald spectrograms: P = 21.64 days, e = 0.0 (assumed), K = 130 km/sec, y (He ii 4686) = +59 km/sec, y (N v 4603) = -119 km/sec, andf(m) = 4.94. Absorption lines near X 3873 and X 4453 have been measured and identified as He i displaced to the violet by approximately 1200 km/sec. These lines were abnormally strong on July 14, 1944, and from observed displacements and changes in dilution we conclude that the He i atoms recede from the star with approximately uniform velocity. A similar conclusion was suggested from earlier observations of HD 214419. The spectrum of HD 211853, spectral class WN6, has well-defined absorption lines as well as emis- sion bands. For the emission bands alone, the following elements are obtained: P = 6.6864 days, e = 0.0 (assumed), K = 245 km/sec. The gamma-velocities of Hen 4686 and N v 4603 are in good agree- - ment, both bands being displaced to the red, with respect to N iv 4058, by 200 km/sec. None of the emission gamma-velocities agrees with that of the absorption lines. The measurements of the absorption lines give a strange velocity-curve. If one interprets the velocity-curve as that of the early B companion with K = 95 km/sec, we have the following minimum masses for the two components: MWR Sin3 i 7.6 0 and MB sin3 i = 19.6 0. The line Hen 4686 undergoes variations in structure. The available data on discrepant gamma-velocities are collected and briefly discussed Publication: The Astrophysical Journal Pub Date: May 1945 DOI: 10.1086/144726 Bibcode: 1945ApJ...101..356H full text sources ADS |
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