Optical Counterpart of the LMXB GX 13+1
We have observed the IR counterpart of the Atoll type LMXB GX 13+1, (Naylor, Charles & Longmore 1991), from 1993 July 11⋯ 30, with the Dutch 90 cm telescope at ESO using a Gunn z (0.9-1.0 µm) filter. Over this period 110 usable images (integration time 12 m) were obtained. The data were reduced using the ESO-MIDAS/DAPHOT reduction package. A Lomb-Scargle period search was performed with the PERIOD package.