The Galactic Structure in Taurus. I. Surface Distribution of Stars.

In order to study the structural features of the galaxy toward the anti-center, general star counts to photographic magnitude 15 have been made in an area of óoo square degrees in Taurus between a 2h40m and 5hi40m and ~ +200 to +35°. The magni- tude scale corresponds essentially to the International Photographic Scale, although there may be a systematic difference amoi.mting to possibly 0.2 mag. for the brightest stars. The surface distribution of stars in arbitrarily selected regions of little or no obscura- tion is given in Table 4 and is compared with similar data by others. It is found that these areas exhibit an excess of 0.2 in log J\7 (m) over the data published by van Rhijn and by Seares and Joyner. An examination of the plates shows that this excess is un- doubtedly due to the obscuring nebulosity overlying the Selected Areas on which previous stellar distributions in this region have been based. With the mean values of log N(m) in the clear areas as a basis, the amount of absorp- tion of photographic light at magnitude i5 has been determined for small subareas, the distribution being shown by a chart and by a contour map (Figs. i and 3). The total absorption at the fifteenth magnitude in the condensations of the Taurus region reaches values as high as 3.5-3.7 mag. Over much of the region the obscuration amounts to 1.5-2.5 mag. The stellar space density in Taurus and a discussion of the dark nebulae will be presented in a succeeding paper