TWO INDEPENDENT PHOTOELECTRIC LIGHT CURVES AND SOLUTIONS OF W URSAE MINORIS

Results of two independent multicolor photoelectric studies of W UMi are presented. Good photometric elements are derived for each and found in veiy close agreement. D. S. H. and D. H. W. found k = 0.78 ± 0.02 whereas E.J.D.found k= 0.77 ± 0.01. All available times of minimum are examined and a new ephemeris derived. Spectroscopie complications are discussed; the range of reasonable absolute dimensions is estimated, and the primary is shown to lie above the main sequence. The (U— B), (B— V) indices indicate a spectral type for the primary of A3 ± 2, in close agreement with its known spectroscopie classifications. After correction was made for reflection, the secondary revealed an intrinsic surface brightness corresponding to a K0 (IV) star but with an untraviolet excess of ä δU-B: = 1ṃ3 ± Oṃ2.