Data sources:
s1,s2: BVRc photometry by D.V. Oparin, R.I. Uklein, E.A. Malygin,
V.P. Goranskij and with the Russian 6-m BTA telescope and SCORPIO-1 and
SCORPIO-2 cameras.
z: CCD BVRc photometry by V.P Goranskij with the SAO 1-m Zeiss
telescope.
A5: CCD BVRc photometry by V.P Goranskij with the SAI 50-cm
Maksutov meniscus telescope and Apogee Alta U8300 camera.
telescope.