Notes. The brightness detected with the optical monitor (OM) is given when the source was in the field of view of this detector and bright enough for a detection. x marks the sources that are outside of the FoV of the OM detector. For source 1 only the probable identification 1RXS J150841.2-621006 (Voges et al. 2000) is mentioned (the possible identification with the ROSAT source is underlined by the flux of CXOU J150850.6-621018/XMMU J150851.1-621017 and its spectral shape). The Tycho-2 catalog (Hog et al. 2000) and the second-generation guide star catalog (Lasker et al. 2008) have been inspected when searching for possible counterparts. The search for reasonable counterparts included not only the three standard deviations uncertainty in the X-ray position (which is determined with a PSF fit), but also the extension of the source. Considering the systematics (Harris et al. 1998), X2 is spatially also compatible with the ROSAT source 1RXS J150841.2-621006.