Photometric Behavior of Five Long-Period Pulsating Stars
  The variation of average brightness during the time and the variation of the
amplitude of the Mira-type stars T Cep, X CrB, U UMi, U Cyg, BG Cyg is studied.
For the research, the observations of the members of the French association of
observers of variable stars (AFOEV) covering almost 100 years are used. All
stars show cyclic variations of the specified parameters. For T Cep, U UMi and
U Cyg, the values of quasi-period of the variations of average brightness are
about 1400, 1025 and 1680 days, respectively. For the stars T Cep, U UMi and BG
Cyg, the period of the brightness variations changes, but we used a mean one.
The dependences {\guillemotleft}average brightness - JD{\guillemotright} and
{\guillemotleft}amplitude - JD{\guillemotright} are plotted. Results are
discussed.
