AAVSO HOME > publications > ejaavso

Photometry of Hipparcos Variable Stars


Therese A. Ostrowski

Robert E. Stencel

Dept. of Physics and Astronomy

University of Denver

Denver, CO 80208


Presented at the 87th Spring Meeting of the AAVSO, June 20, 1998




Among the discoveries reported by the Hipparcos team was the detection of short-term photometric fluctuations in several long period, or Mira, variables (de Laverny et al. 1998). Nearly 15 percent of the 250 Miras surveyed in the broadband 380 to 800 nm filter showed variation of 0.2 to 1.1 magnitudes on timescales of 2 to 100 hours, preferentially around minimum light phases. We have begun an observational effort to confirm these variations. We seek to correlate the behavior with ancillary information, such as optical and infrared spectra plus maser data, to determine whether the fluctuations can be understood as thermal instabilities or so-called molecular catastrophe (cf. Muchmore et al 1987; Stencel et al. 1990). A progress report and call for observation coordination are given.


Link to ADS abstract, article and citation information


  search engine |  site map |  links |  contact us