  Very recently, J 1128+5925 was found to show strong intraday variability at
radio wavelengths and may be a new source with annual modulation of the
timescale of its radio variability. Therefore, its radio variability can be
best explained via interstellar scintillation. Here we present the properties
of its optical variability for the first time after a monitoring program in
2007 May. Our observations indicate that in this period J 1128+5925 only showed
trivial optical variability on internight timescale, and did not show any clear
intranight variability. This behavior is quite different from its strong radio
intraday variability. Either this object was in a quiescent state in optical in
this period, or it is intrinsically not so active in optical as it is in radio
regimes.
