During two observation periods in 1984 and 1985 we monitored the faint optical counterparts of seven X-ray binaries with a CCD camera attached to the Cassegrain-focus of the 2.2 m telescope at Calar Alto , Spain. The observation periods were 1984, September 25–27 , and 1985, August 8–15.
The transient sources 4U0042+32 and 4U0115+63 showed no active state.
The search for an optical candidate of 4U0142+62 did not reveal any object mv
≤ 24 within the EXOSAT error box.
Within the EXOSAT error box of EXO2030+37 the reddest object was found to be very faint in blue in contrast to the blue Palomar plate.
The analysis of the other three observed sources 4U1837+04 , 1H1929+509 , and 4U2129+47 is not yet finalized , but no unexpected bright or faint state of the sources has been found. 4U2129+47 is still in its present low state (mv
= 18) , lasting at least since 1983.