Astronomy and Astrophysics, volume 400, 279-291 (2003/3-2)
Long-term spectroscopic monitoring of the Luminous Blue Variable HD 160529.
STAHL O., GAENG T., STERKEN C., KAUFER A., RIVINIUS T., SZEIFERT T. and WOLF B.
Abstract (from CDS):
We have spectroscopically monitored the galactic Luminous Blue Variable HD 160529 and obtained an extensive high-resolution data set that covers the years 1991 to 2002. During this period, the star evolved from an extended photometric minimum phase towards a new visual maximum. In several observing seasons, we covered up to four months with almost daily spectra. Our spectra typically cover most of the visual spectral range with a high spectral resolution (λ/Δλ≃20000 or more). This allows us to investigate the variability in many lines and on many time scales from days to years. We find a correlation between the photospheric Hei lines and the brightness of the star, both on a time scale of months and on a time scale of years. The short-term variations are smaller and do not follow the long-term trend, strongly suggesting different physical mechanisms. Metal lines also show both short-term and long-term variations in strength and also a long-term trend in radial velocity. Most of the line-profile variations can be attributed to changing strengths of lines. Propagating features in the line profiles are rarely observed. We find that the mass-loss rate of HD 160529 is almost independent of temperature, i.e. visual brightness.
stars: individual: HD 160529 - stars: early-type - stars: emission-line, Be - stars: variables: general - stars: mass-loss