CAOSP abstracts, Volume: 30, No.: 1, year: 2000
- Author(s): ZBORIL, M.; NORTH, P.
- Journal: Contributions of the Astronomical Observatory Skalnate Pleso,
vol. 30, no. 1, p. 12-20.
- Date: 04/2000
- Title: He, CNO abundances and (v sin i) values in He-rich stars
- Keyword(s): STARS, ABUNDANCES, ATMOSPHERES, CHEMICALLY PECULIAR
- Pages: 12 -- 20
Abstract:
We present projected rotational velocities distribution in He-rich stars
against normal B type stars as well as the abundance analysis of light elements
and their comparison with results of earlier series. The analysis is based on
high-resolution observations (R=40000) collected at ESO, La Silla, Chile in the
optical region and includes 11 stars, amongst them 5 new stars in comparison
with an earlier sample. The distribution of projected rotational velocities
shows a significant excess of slow rotators, no He-rich stars having
v sin i > 130 km/s at the significance level of 99.5%. Based on fully
consistent LTE models, the helium abundance ranges from 0.1 (solar) to 0.4.
The analysis on the new sample confirms the results of earlier paper: the light
element abundances display a diverse pattern from under-solar up to above-solar
values. Carbon has the same abundance in He-rich and in standard stars for
cool He-rich stars, following the predictions of radiative diffusion in the
presence of wind. The star HD149363 appears rather as He-weak as based on the
equivalent widths from R=40 000 spectra.
Full text version of this article in
PostScript
(600dpi) format compressed by gzip; or in
PDF.
