UXORs: A Unique Opportunity to Study Disk Structure
Bernadette Rodgers, Gemini Observatory
What distinguishes UXORs among the seemingly ubiquitous photometric and polarimetric variability of pre-main sequence stars, is the magnitude of their variations (i.e., delta V > 1.5, delta pol > 2%). If occultation by circumstellar disk material is the cause of the variability in these stars, these obscuration events provide an opportunity to study the structure and behavior of disks through the effects they have on the starlight. Spectral monitoring of the UXOR star RR Tau (Rodgers et al. 2002) shows that variability across the optical spectrum is well-correlated with the photometric changes and allows us to place constraints on the size of obscuring material. With more detailed modeling, these kind of data have the potential to probe in detail how the circumstellar gas is effected and/or implicated in the variability known as the "UXOR phenomenon".
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