Proposal #583

I propose systematic BVRI observation of rare RVa variable FW Boo which has clear double minima cycles with period about 110 days. Positition of star gives the opportunity of all-year observations with BSM telescopes.

The star has been observed during 10 years from 2008 to 2018 by Alain Bruno (code BOA), who presented 175 V and TG estimations. ASAS-SN survey gives reliable light curves of FW Boo with dencer points in V and g bands, but there is not data for standard color indexes calculation. However, the effect of phase delay for color indexes of RV Tauri stars is known, well as indexes changes during pulsations. That is why proposed BVRI observations may bring important information on physical processes in post-AGB pulsators additionally to well-known data on their short- and long-term variations and spectral features.

I suppose, one year of frequent observations (from January to December of 2025) will cover 3 cycles and it will be enough for determination of phase delays and color indexes behavour. Frequency may be about 2-3 days. It is important to find exposures in each band for reliable photometry, especially at the brightness minimum.