Abstract
ROTSE-IIId observations of the Be/X-ray transient system KS 1947+300 obtained
between September 2004 and December 2005 make it possible to study the
correlation between optical and X-ray activity. The optical outburst of 0.1 mag
was accompanied by an increase in X-ray flux in 2004 observations. Strong
correlation between the optical and X-ray light curves suggests that neutron
star directly accretes from the outflowing material of Be star. The nearly zero
time lag between X-ray and optical light curves suggests a heating of the disk
of Be star by X-rays. No optical brightening and X-ray enhancement was seen in
2005 observations. There is no indication of the orbital modulation in the
optical light curve.