Proceedings of the International Astronomical Union

Contributed Papers

Disk-loss and disk-renewal phases in classical Be stars – II. Detailed analysis of spectropolarimetric data

Zachary H. Drapera1, John P. Wisniewskia1, Karen S. Bjorkmana2, Jon E. Bjorkmana2, Xavier Hauboisa3, Alex C. Carciofia3 and Marilyn R. Meadea4

a1 Department of Astronomy, University of Washington, email: zhd@u.washington.edu, jwisnie@u.washington.edu

a2 Ritter Observatory, Department of Physics & Astronomy, University of Toledo

a3 IAG, Universidade de Sao Paulo

a4 Space Astronomy Lab, University of Wisconsin-Madison

Abstract

In Wisniewski et al. (2010), paper I, we analyzed 15 years of spectroscopic and spectropolarimetric data from the Ritter and Pine Bluff Observatories of 2 Be stars, 60 Cygni and π Aquarii, when a transition from Be to B star occurred. Here we analyze the intrinsic polarization, where we observe loop-like structures caused by the rise and fall of the polarization Balmer Jump and continuum V-band polarization being mismatched temporaly with polarimetric outbursts. We also see polarization angle deviations from the mean, reported in paper I, which may be indicative of warps in the disk, blobs injected at an inclined orbit, or spiral density waves. We show our ongoing efforts to model time dependent behavior of the disk to constrain the phenomena, using 3D Monte Carlo radiative transfer codes.

Keywords

  • circumstellar matter;
  • stars: individual (π Aquarii, 60 Cygni)