| Popis: |
Differential U,B,V observations of the magnetic Ap stars CU Vir, β CrB, χ Ser, and HD 173650 obtained with the Phoenix 10 in. telescope of the Fairborn Observatory are analyzed along with uvby data taken with the 0.4 m telescope of Kitt Peak National Observatory. Our refined periods, 0.520 680 days for CU Vir, 1.595 83 days for X Ser, and 9.975 48 days for HD 173650, differ only slightly with those in the literature. For CU Vir the shapes of the light curves vary from observer to observer suggesting that this star may be precessing |
