Variability of GX 3+1 observed with EXOSAT.

The authors report results from an observation of the X-ray source GX 3+1 carried out with the EXOSAT satellite on 1983, October 23. The source showed a strong X-ray variability in excess of the counting statistics noise. This variability increased toward low frequencies ("red noise") and was different in different energy bands, with the lower energy X-rays showing a more pronounced increase of the variability at low frequencies. The variation function of the source is also shown to depend on energy, with the highest values associated with the highest energies. A comparison of the time variability properties of GX 3+1 with those of other bright low mass X-ray binaries is presented.