Proposal #74

Stars classified "Be" are stars with B spectral types AND conspicuous hydrogen and helium emission lines. Many of these stars are main sequence stars that exhibit low level irregular variability (~0.1 mag) and changes in the profiles of their emission lines. Many Be stars a known to unpredictably turn off and then later re-estabilsh their emission. There is some evidence that the phenomenon is associated with binary but it cannot be conclusively stated that all Be stars are binary. The best hypothesis is that the emission lines are produced in circumstellar gas, probably in the form of an excretion disk formed from the radiatively driven stellar wind. Although there have been may theoretical attempts to comprehensively model the Be phenomenon there is no comprehensive theoretical model for the disks or how they form and dissipate.

Be stars have been a popular target among non-professionals doing spectroscopy. See the Be Star Spectra Database (BeSS; http://basebe.obspm.fr/basebe/)
For the last 10+ years the University of Illinois Springfield Barber Observatory has conducted long term spectroscopic monitoring of several Be Stars at high spectroscopic resolution of the full visual range (https://sites.google.com/a/uis.edu/uis-barber-research-observatory/research-programs/be-stars/).
While spectroscopic databases exist covering these stars, the photometry is thin, particularly for the bright Be stars which are easiest for non-pros to take spectra of and are also too bright for most telescopes to monitor photometrically. Photometry is useful because it can give useful information about the change in overall energy output and effective surface temperature of the star, which is more difficult to obtain exclusively from spectroscopy.
At the UIS Barber Observatory we have conducted a PEP photometry program of these stars. But our coverage and sampling of them has been sparse and irregular. The community could benefit from a more uniform dataset that BSM monitoring could provide.
Many Be stars are listed in the BSM Epoch Photometry Database but they have few data points and none more recent than several years ago.

The time scale of changes in Be stars is usually measured in months or years. We propose monthly or bimonthly Johnson B and V photometry from BSM images over an indefinite period going forward. I propose to do this as a public service to the bright Be Star community, making the data immediately available in WebObs (with NO proprietary period) as soon as it is reduced.