AAS 205th Meeting, 9-13 January 2005
Session 53 Hot Stars, Atmospheres and Winds
Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall

Previous   |   Session 53   |   Next

[53.05] Properties of the H\alpha-emitting Circumstellar Regions of Be Stars

C. Tycner (NOFS), NPOI Collaboration

Long-baseline interferometric observations obtained with the Navy Prototype Optical Interferometer of the H\alpha-emitting envelopes of the Be stars \eta~Tauri and \beta~Canis~Minoris are presented. For compatibility with the already published interferometric results in the literature of other Be stars, circularly symmetric and elliptical Gaussian models are fitted to the calibrated observations in H\alpha. The models are sufficient in describing the overall angular extents of the circumstellar regions associated with these Be stars. To study the correlations between the various model parameters and the stellar characteristics, the model parameters for \eta~Tau and \beta~CMi are combined with data for other Be stars found in the literature. After accounting for the different distances to the sources and stellar continuum flux levels, it is possible to study the relationship between the net H\alpha emission and the physical extent of the H\alpha-emitting circumstellar region. A clear dependence of the net H\alpha emission on the extent of the emitting region is demonstrated and these results are consistent with an optically thick line emission that is directly proportional to the effective area of the emitting disk. Within the small sample of stars considered in this analysis, no clear dependence on the spectral type or stellar rotation is established.

This work was performed in part under funding from the Government of Ontario Graduate Scholarship in Science and Technology and Walter C. Sumner Fellowship, as well as in part under contract with the Jet Propulsion Laboratory (JPL) funded by NASA through the Michelson Fellowship Program. JPL is managed for NASA by the California Institute of Technology.

Previous   |   Session 53   |   Next

Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.