AAS 205th Meeting, 9-13 January 2005
Session 54 Pulsating Stars: RR Lyraes, Miras, Cepheids, etc.
Poster, Tuesday, January 11, 2005, 9:20am-6:30pm, Exhibit Hall

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[54.06] Automated photometry, period analysis and flare-up constraints for selected Mira Variable Stars

D.E. Mais (Department of Astronomy, Palomar College, San Marcos, CA), R.E. Stencel (Department of Physics and Astronomy, University of Denver), D. Richards (Aberdeen and District Astronomical Society, UK)

During the course of the past two years, 108 selected Mira-type program stars have been monitored to address potential flare up episodes. These include 34 M-type, 17-S type and 57 C-type Mira’s. This poster will describe the greater than 100,000 magnitude determinations that have been obtained, many closely spaced in time, which are being used to further constrain the potential occurrences of flare-up events. Random reports in the literature suggest that some Mira variables may go through flare up stages, which result in brightening on the order of several tenths of a magnitude or more, and may last hours to days in length. Very little is known about these events and their frequency, indeed, it is not clear that these events are real or instrumental phenomena. The light curves of many of the program stars show a Cepheid like bump phenomenon, usually on the ascending part of the light curve. In general, these bumps appear in longer period Mira’s (>350 days) as pointed out by Melikian in 1999. Bumps are not obvious or easily seen in visual data records, although slope changes during rising phase are seen in some cases. In order to address the reality of these events, we established an automated acquisition/analysis of a group of 108 Mira variables [M(oxygen), S and C types] in order to obtain the densest possible coverage of the periods, to better constrain the character and frequency of flare-ups. Telescope control scripts were put in place along with real time analysis. This allowed for unattended acquisition of data on every clear night, all night long, in the V, R and I photometric bands. In addition, during the course of most nights, multiple determinations are often obtained for a given star. We are grateful to the estate of William Herschel Womble for partial support of these efforts.

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© 2004. The American Astronomical Society.