Astronomy and Astrophysics – Astrophysics
Scientific paper
Jan 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990phdt........11f&link_type=abstract
Ph.D. Thesis Toronto Univ. (Ontario). Dept. of Astronomy.
Astronomy and Astrophysics
Astrophysics
56
Absorption Spectra, O Stars, Stellar Oscillations, Supergiant Stars, Astronomical Spectroscopy, Astrophysics, Line Spectra, Variable Stars
Scientific paper
A spectroscopic survey was conducted of a magnitude limited sample of O stars to search for absorption line profile variations, particularly those that are commonly attributed to nonradial pulsations. The final sample consisted of 32 stars with spectral types between O 4 and O 9.7 that covered the full range of luminosity classes. Through the use of an objective statistical technique significant variations were detected in the shapes and strengths of the lines for 75 +/- 15 percent (24/32) of the sample. The incidence of variability appears to be primarily a function of luminosity: all the supergiants in the sample exhibited line profile variations, while 7 of the 8 constant stars are dwarfs. Similarly, the amplitude of the line profile variations appears to correlate positively with indicators of luminosity, though the correlations are suggestive rather than definitive. No dwarf earlier than O 8 exhibited variations in the data. The large-amplitude variations observed in the line profiles of supergiant stars were associated with the formation and evolution of overdense structures in their stellar winds. For stars of lower luminosity, the line profile variations could be due to pulsation, rotational modulation, or the evolution of structures in the stellar wind. However, the variability of one of these objects, HD 34656, is almost certainly due to radial pulsation. This discovery constitutes direct proof that O-type stars are pulsationally unstable.
No associations
LandOfFree
The incidence and nature of absorption line profile variations among the O stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The incidence and nature of absorption line profile variations among the O stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The incidence and nature of absorption line profile variations among the O stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1564260