Astrophysical: O stars

  • Publication
    A spectrophotometric study of the peculiar young open cluster Berkeley 87
    A spectrophotometric study of the peculiar open cluster Berkeley 87 is presented; the measurements show that most of the members are young, heavily reddened OB...
  • Publication
    An automatic procedure for a determination of the effective temperature and gravity - Application to 100 O-type stars
    We have developed an automatic procedure to determine Teff and log g from the comparison of observational data with their theoretical values. After a...
  • Publication
    Analysis of UV spectrophotometric observations for O-type stars
    Spectral indices (delta m2100 and delta m1500) for 32 O-type stars with known spectral class and reddening are plotted versus log of effective temperature. The...
  • Publication
    Improved non-LTE Balmer-line profiles for hot stars
    Improved non-LTE line formation calculations for hydrogen in O-stars are presented. The calculations are carried out by means of the method recently developed...
  • Publication
    Intrinsic parameters of galactic luminous OB stars
    We present the results of a spectroscopic analysis of 25 galactic luminous OB stars. The gravities are in general lower than previously assumed, especially for...
  • Publication
    Multi-level non-LTE calculations for very optically thick winds and photospheres under extreme NLTE conditions
    A new technique to calculate multilevel non-LTE continuum formation in the UV of stellar winds and plane-parallel, static stellar atmospheres is developed using...
  • Publication
    NLTE analysis of massive OB stars in open clusters
    The paper presents a new method for deriving stellar masses and distances using the theory of radiatively driven winds as presented by Kudritzki et al. (1989)...
  • Publication
    Observations of massive OB stars
    Preliminary results are presented of spectroscopic analysis of ten young stars in OB associations using high resolution spectra and NLTE calculations. From the...
  • Publication
    On the massive star-forming capacity of molecular clouds
    Assuming that photoionization is the self-limiting process for continued star formation, we estimate the maximum number of massive (OB) stars that can form...