Optical observations of the Draco molecular cloud I. Catalog of B and V magnitudes for selected areas

To investigate the distance and linear dimensions of the Draco Molecular Cl oud (MBM 41) we have obtained new CCD photometry for a selection of stars i n 20 selected areas toward the cores of the cloud. The selected areas were chosen to coincide with the brightest IRAS emitting portions of the cloud, and also with dense (CO)-C-12 emission from the cloud. For each area we hav e obtained V and B photometry, and a subset of the fields has also been obs erved through a narrow-band Ha filter and in the U band. We present V and B magnitudes for the 362 stars which have high-quality obs ervations in both bands. In addition we have derived star counts in the V b and using a larger sample of 465 stars, which is complete to a limiting mag nitude of V=19.0. The star counts were compared to a galactic model from Ba hcall & Soneira (1980). Using the galactic model of star counts, slightly m odified to include the effects of a cloud of arbirary distance and extincti on, we find a best fit to our data with values of A(V) = 2.5 and 800 < d < 1300 pc for the Draco molecular cloud. We also report results of photometri c spectral classification using the index [V - alpha], which was found to c orrelate well with (B - V)(0) for our photometric standard stars. The model led B - V colors of the stellar sample were compared with the catalog value s, and the observed colors best matched a cloud distance of d = 1100(-300)( +200) pc, with A(V) = 2.5 +/- 0.5 and R-V = 1.5. Our photometry detects red dening and extinction from the densest portions of the Draco cloud, and it seems likely that the cloud is within the range of distances 800 < d < 1300 pc, which corresponds to a height \z\ = 640 pc above the galactic plane, a nd linear dimensions as large as 40 pc for the cloud.