Identification of candidates. Red and blue circles correspond to possible candidates according to the position in the Q/K_S diagram, while purple circles correspond to candidates from the optical diagram. The image size is 8.5′ × 8.5′. The X-ray position is RA = 19h03m37s.1, Dec = +3 11′31′′ (equinox 2000.0; estimated 1’ uncertainty at 90% confidence, Galloway et al. 2003). Stars A and B are not the optical counterpart because they are late-type stars (Galloway et al. 2005). Image taken from the Digitized Sky Survey (DSS), available through the Skyview Virtual Observatory (http://skyview.gsfc.nasa.gov/current/cgi/titlepage.pl).