VLT search for the infrared counterpart of 1E 1740.7-2942
  We report the results of our search for the near infrared counterpart of the microquasar 1E 1740.7-2942 using the VLT (Based on observations collected at the European Southern Observatory, Chile (ESO No 63.H-0261)). For the first time, several counterpart candidates have been found in our Ks-band images that may be consistent with the best radio and X-ray positions available for 1E 1740.7-2942. However, the non-detection of variability between two observing epochs and the positional uncertainty still remaining at the nearly less than 1 arcsec level prevent us from identifying an unambiguous counterpart. Alternatively, the VLT images set new upper limits significantly deeper than previously reported that constrain the binary companion to be later than B8 V or earlier than G5 III. 
Josep Marti, I. Felix Mirabel, Sylvain Chaty, and Luis F. Rodriguez