Globular cluster NGC 6397

The globular cluster NGC 6397, located at a distance of approx. 7,200 light-years in the southern constellation Ara. It has undergone a "core collapse" and the central area is very dense. It contains about 400,000 stars and its age (based on evolutionary models) is 13,400 ± 800 million years. The photo is a composite of exposures in the B-, V- and I-bands obtained in the frame of the Pilot Stellar Survey with the Wide-Field-Imager (WFI) camera at the 2.2-m ESO/MPI telescope at the ESO La Silla Observatory. It was prepared and provided by the ESO Imaging Survey team. The spikes seen at some of the brighter stars are caused by the effect of overexposure (CCD "bleeding").