AAS 200th meeting, Albuquerque, NM, June 2002
Session 74. Stellar Atmospheres and Circumstellar Material
Display, Thursday, June 6, 2002, 9:20am-4:00pm, SW Exhibit Hall

[Previous] | [Session 74] | [Next]

[74.13] Probing the Circumstellar Environment of pi Aquarii Using Intrinsic Linear Polarization

J.P. Wisniewski, K.S. Bjorkman, J.E. Bjorkman, G. Summers (U. Toledo), M.R. Meade (U. Wisconsin)

We present the intrinsic linear polarization of the classical Be star pi Aquarii obtained from 1989-2002 and covering the wavelength region of 3200-10500 Å. Correlating spectroscopic and polarimetric observations during two polarimetric outbursts, we assert that the underlying cause of these outbursts is not due to a change in the global density distribution of the circumstellar disk. Density changes resulting from mass transfer from a binary system are also excluded. Rather, we show that the source of the density enhancements responsible for these sudden rises in polarization must be localized to the inner disk region, suggesting that the central star is responsible for these outbursts. Modelling the wavelength dependence of the intrinsic polarization, we determine the fundamental disk parameters of disk opening angle and optical depth. We also show that the disk ionization temperature diagnostic, developed by Bjorkman, Bjorkman, and Wood (2002) using UV and visible spectropolarimetry, can be successfully applied even in the absence of available UV data. These results and their implications on our understanding of the Be phenomenon will be discussed. This work was supported by NASA grants NAG5-3248 and NAG5-8054. KSB is a Cottrell Scholar of the Research Corp., and gratefully acknowledges their support.

The author(s) of this abstract have provided an email address for comments about the abstract: jwisnie@physics.utoledo.edu

[Previous] | [Session 74] | [Next]

Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.