Physics
Scientific paper
Mar 1993
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1993ssrv...66..271c&link_type=abstract
Space Science Reviews, Volume 66, Issue 1-4, pp. 271-275
Physics
6
Stars:Atmospheres, Stars:Wolf-Rayet, Stars:Abundances, Stars:Winds, Stars:Massloss
Scientific paper
The fundamental properties of 24 Galactic WN stars are determined from analyses of their optical, UV and IR spectra using sophisticated model atmosphere codes (Hillier, 1987, 1990). Terminal velocities, stellar luminosities, temperatures, mass loss rates and abundances of hydrogen, helium, carbon, nitrogen and oxygen are determined. Stellar parameters are derived using diagnostic lines and interstellar reddenings found from fitting theoretical continua to observed energy distributions. Our results confirm that the parameters of WN stars span a large range in temperature (T*=30 90,000 K), luminosity (log L*/L&sun;=4.8 5.9), mass loss (M=0.9 12×10-5 M&sun; yr-1) and terminal velocity (v ∞=630 3300 km s-1). Hydrogen abundances are determined, and found to be low in WNEw and WNEs stars (<15% by mass) and considerable in most WNL stars (1 50%). Metal abundances are also determined with the nitrogen content found to lie in the range N/He=1 5×10-3 (by number) for all subtypes, and C/N ˜0.02 in broad agreement with the predictions of Maeder (1991). Enhanced O/N and O/C is found for HD 104994 (WN3p) suggesting a peculiar evolutionary history. Our results suggest that single WNL+abs stars may represent an evolutionary stage immediately after the Of phase. Since some WNE stars exist with non-negligible hydrogen contents (e.g. WR136) evolution may proceed directly from WNL+abs to WNE in some cases, circumventing the luminous blue variable (LBV) or red supergiant (RSG) stage.
Crowther Paul A.
Hillier Desmond John
Smith Linda J.
No associations
LandOfFree
Tailored analyses of 24 Galactic WN 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 Tailored analyses of 24 Galactic WN stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tailored analyses of 24 Galactic WN stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1708009