Stars of the Draco dwarf spheroidal galaxy beyond its measured tidal boundary

We report R- and V-band photometry derived from CCD imaging for objects in nine fields in and around the Draco dwarf spheroidal galaxy. The most dista nt fields are about from the center. We 1.degrees3 use these data to search for Draco stars outside of its measured tidal boundary. The search involve s three methods: (1) plotting color-magnitude diagrams for individual field s, for sections of fields, and for combined fields and sections-a colour-ma gnitude diagram can reveal a population of Draco stars by the presence of t he expected principal sequences; (2) measuring field-to-field fluctuations in the surface density of objects located near the Draco principal sequence s in the color-magnitude diagram; (3) measuring intrafield fluctuations in the surface density of those objects. We find evidence for the presence of Draco stars immediately beyond the measured tidal boundary of Draco and pla ce an upper limit on the number of such stars in more distant fields that l ie close to the extension of its major axis. The best evidence is the prese nce of the Draco principal sequences in the color-magnitude diagram for som e combined fields and sections of fields. The measurements of the field-to- field fluctuations in the stellar surface density confirm this result.