A photometric and spectroscopic study of the B[e]/X-ray transient CI cam

We compare U BV R photometry of CI Cam obtained using facilities at the Sternberg Astronomical Institute in 1998-2001 and medium-resolution spectroscopy obtained at the Special Astrophysical Observatory in the same period. The photometric measurements and fluxes in the Balmer and some Fe 11 emission lines in the post-outburst quiescent spectrum of CI Cam display cyclic variations with a period of 1100+/-50(d). These variations could be due to orbital motion in a widely separated binary; one component, a giant, produces a reflection effect on the surface facing the other, compact component. Our V-band photometry confirms the 11(d)7 period found by Miroshnichenko before the outburst but shows a lower amplitude (3%). We investigate the possibility that this photometric period is the same as the rotational period of the radio jets measured using the VLA. Based on modeling of the radio map, we estimate the inclination of the jet rotation axis to the line of sight, i = 35degrees-40degrees; the angle between the rotational axis and jet ejection direction, theta = 7degrees-10degrees; and the jet spatial velocity, 0.23-0.26 c. The equivalent widths and fluxes of various spectral lines show different variation amplitudes during outburst and significantly different behavior during quiescence. We have detected five patterns of behavior, which provide evidence for stratification of the gas and dust envelope surrounding the system. The brightening of the [NII] forbidden line is delayed by 50-250(d) relative to the X-ray outburst maximum. (C) 2002 MAIK "Nauka/Interperiodica".