• stars: individual: SLX 1735−269;
  • stars: individual: 3A 1742−294;
  • stars: individual: SLX 1744−299;
  • stars: individual: SLX 1744−300;
  • infrared: stars;
  • X-rays: binaries


We report on the archival optical and near-infrared observations of six low-mass X-ray binaries situated in the Galactic bulge. We process several recent Chandra and XMM–Newton as well as Einstein data sets of binary systems suspected to be ultracompact, which give us arcsec-scale positional uncertainty estimates. We then undertake a comprehensive search in existing archives and other Virtual Observatory resources in order to discover unpublished optical/near-infrared data on these objects. We find and analyse data from European Southern Observatory Archive and UKIRT Infrared Deep Sky Survey on SLX 1735−269, 3A 1742−294, SLX 1744−299, SLX 1744−300, GX 3+1 and IGR J17505−2644 systems and publish their finding charts and optical flux constraints in this paper, as well as simple estimates of the physical parameters of these objects.