Abstract

The Luminous Blue Variables: Recent Spectroscopic and Interferometric Observations

Noel Richardson (Georgia State University)

Douglas R. Gies, Georgia State University

We report on the preliminary results of a three-year monitoring campaign of Galactic and Magellanic LBVs with both moderate and high resolution spectroscopy. We have collected more than 500 moderate-resolution spectra of 20 stars in the red portion of the optical spectrum, which includes the wind-sensitive transitions of H-alpha and He I 5876 and 6678 Angstroms. We present initial results on the wind variability and multiplicity of the sample. We find several stars exhibiting observational evidence of changes in the emission line morphology that reflect changes in the ionization structure of the wind. Additionally, we will discuss recent observations of eta Car, highlighting its unusual recovery from the previous periastron passage. Our results on HD 326823 indicate that the star is rotating rapidly and has a strong magnetic field. We also present a detailed study of 15 years of high resolution H-alpha spectroscopy of the prototypical luminous blue variable, P Cygni. We report on the discovery of discrete absorption components in P Cygni's H-alpha profile, and we discuss their relationship to structure of the wind. These results are compared to our recent high resolution interferometric imaging of the H-band emitting region surrounding the star.