Combined photometry and spectroscopy projects

Be stars are monitored spectroscopically (overwhelmingly at H-alpha) by amateurs probably more than any other group of variable stars, but there has been little virtually simultaneous photometric and spectroscopic monitoring of these stars done by amateurs.  That's a fertile, pretty much wide-open field for amateurs, much as eclipsing binaries were 50 years ago.  It also provides opportunities for collaborative programs amongst amateur photometrists and spectroscopists, as well as for pro-am co-operation.  Here's a link to an interesting paper that points up the need for simultaneous photometry and spectroscopy of Be stars, and the science that can come from those observations:

The Correlation Between H-alpha Emission and Visual Magnitude During Long-Term Variations in Classical Be Stars

T. A. A. Sigut and P. Patel

Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, CANADA N6A 3K7

H-alpha equivalent widths and UBV magnitudes are calculated for Be star disk models that grow in size and/or density with time. We show that these simple models are consistent with the known Be star classes of positive and inverse correlations between long-term variations in H-alpha and V magnitude as identified by Harmenac. We support the conclusion of Harmenac that the distinction is controlled by the inclination of the disk to the line of sight. We demonstrate that the strength of these correlations, particularly those of an inverse correlation where the system becomes fainter as the H-alpha emission strength grows, is strongly influenced by the scale height of the inner Be star disk and the extent of the gravitational darkening of the central B star due to rapid rotation. This dependence may allow coordinated spectroscopic and photometric observations to better constrain these poorly known Be star parameters.

Accepted by The Astrophysical Journal
Preprints from: asigut@uwo.ca [1]
or on the web at: arXiv:1301.3721 [2]

The "Visual Magnitude" in the title refers to V-filtered photometry, but long-term visual monitoring of Be stars is equally important as, similar to CVs or symbiotics, can go into "outburst" on a more or less regular basis, depending on the star.

Cheers,

Thom Gandet (GTN)