The Magnitude Scale of the Bright Polar Standards.

Recent photoelectric observations by Hassenstein provide an additional test of the photographic scale of the bright polar standards. Comparison with the magnitudes of 40 stars in the new Mount Wilson Polar Catalogue reveals localized zero-point differences of -0.04 and +0.03 mag., which apparently originate in Hassenstein's measurements. After correction the agreement with the Polar Catalogue is close (average difference ± 0.019 mag. and no scale divergence). The agreement with the magnitudes of the first 9 stars of the Polar Sequence is equally close. A direct comparison of Ilassenstein with the photo- electric results of Stebbins and Whitford, on the other hand, shows for stars is and i-~ the same dis- cordance of o.i mag. that appears when the polar standards are compared with Stebbins and Whitford. Although no completely satisfactory explanation has been found, it seems likely that at least part of the discrepancy originates in spectral peculiarities