AAS 201st Meeting, January, 2003
Session 81. Extragalactic Star Clusters
Poster, Wednesday, January 8, 2003, 9:20am-6:30pm, Exhibit Hall AB

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[81.04] Probing Circumstellar Environments in LMC/SMC Clusters

J.P. Wisniewski, K.S. Bjorkman (U. Toledo), A.M. Magalhães (U. de São Paulo), J.E. Bjorkman (U. Toledo)

Circumstellar disks can play an important role throughout the evolutionary history of stars, from influencing the earliest stages of star formation to guiding stellar outflows in the later stages of evolution. While Be stars are known to have circumstellar disks, the specific mechanisms responsible for producing these disks are unclear. It is uncertain whether the Be phenomenon is an evolutionary effect or what role metallicity may play in disk formation. Recent attempts to answer these questions have used a variety of photometric techniques to identify Be/(B + Be) ratios in clusters of various ages and metallicites. Are the candidate Be stars identified by these techniques truly disk-like systems, or are they other types of B-type emission line objects? In an attempt to answer these questions, we have obtained the first UBVRI imaging photo-polarimetry of LMC/SMC clusters with Be candidates identified via photometry. We present the initial results of our observations. From the unique wavelength dependence of polarization originating from Be disks, we identify the true disk systems in these clusters. Future modeling of these data will allow us to derive geometrical parameters for these circumstellar disks.

We thank the NOAO and the CTIO TAC for granting time for these observations. This work has been supported in part by NASA LTSA grant NAG5-8054 to the University of Toledo. KSB is a Cottrell Scholar of the Research Corporation and gratefully acknowledges their support. JPW thanks NOAO for supporting his travel to CTIO. AMM acknowledges travel support by FAPESP; he is also partially supported by CNPq. Polarimetry at University of São Paulo is supported by FAPESP. AMM, KSB and JEB acknowledge partial travel support by USP.

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Bulletin of the American Astronomical Society, 34, #4
© 2002. The American Astronomical Soceity.