1996A&A...314..567K

We report on three observations of the Z source GX340+0 performed with EXOSAT during 1985 and 1986. In two observations the source was in the horizontal branch and the upper part of the normal branch of the Z pattern in the X-ray colour-colour diagram, while in the third observation it was in the normal and flaring branches. We found that the horizontal branch had different orientations and positions in the colour-colour diagram in the two horizontal branch observations. In one of the observations the horizontal branch was vertically oriented, comparable to that in GX17+2 and ScoX-1, while in the other it was more diagonal, comparable to that in CygX-2 and GX5-1. The different positions in the colour-colour diagram are probably due to long term variations in the position of the Z pattern, similar to CygX-2 and GX5-1. In one observation we found some evidence for the presence of a harmonic of the horizontal branch quasi-periodic oscillations. We suggest that GX340+0 is viewed at an inclination intermediate between the high-inclination systems GX5-1 and CygX-2 on the one hand, and the low-inclination systems GX17+2, ScoX-1 and GX349+2 on the other.