Title: Optical Spectroscopic Observations of CI Camelopardalis Authors: Jingzhi Yan, Qingzhong Liu, Hengrong Hang (PMO)
We present the results of optical spectroscopic observations of CI Cam. Double-peaked profiles were simultaneously observed for the first time in the hydrogen Balmer, He I \lambda 6678 and Fe II lines during an observational run in 2001 September. An intermediate viewing angle of the circumstellar disk around the Be star is consistent with our data. A significant decrease in the intensity of the H\alpha and He I lines in our 2004 September observations might have been the precursor of a line outburst at the end of 2004. The remarkable increase in the intensity of all lines and the decrease in visual brightness in 2005 might be due to the environment filling with new material ejected during the outburst. The environment of CI Cam is influenced by mass loss from the Be star and the outburst of its compact companion.