COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 917 Konkoly Observatory Budapest 1974 August 15 MW PAVONIS The variability of MW Pav (BV894 = HD 197070 = CoD-72deg1636) was announced by O.J. Eggen (IBVS 308A, 1968). W. Strohmeier (IBVS 308B, 1968) published a list of observed times of minima and obtained a period of 0d.562979. However, this period was found to be incompatible with minima observed by R.M. Williamon (IBVS 574, 1971) who deduced P = 0d.79499080. In this note we present times of minimum derived from 390 photoelectric UBV observations made at the Bosque Alegre station of Cordoba Observatory with the 1.54m reflecting telescope. Individual minima are listed in Table I together with the older photographic ones from Strohmeier, Eggen and Knigge, and the photoelectric minima from Williamon. They were used to determine the following least square linear ephemerides: Min.I=JD hel 2440862d.6076 + 0d.79498855 E +-.0013 +-.00000091 The W column in Table I gives the weights assigned to each observation. The residuals (O - C) are distributed at random for both minima; therefore, we infer that the secondary minimum is not displaced from phase Phi = 0.5 as pointed out by Williamon (c/f above). The observations of the system will be completed in the next observing seasons; at present, they cover well the secondary minimum and the preceding maximum. The secondary minimum shows constant light during an interval of about 125 minutes, indicating it to be a total occultation. The differential light and color curves are shown in the Figure, the differences are given in the sense variable star -minus- comparison star (HD 197417). 1974 August 1 EMILIO LAPASSET Cordoba Observatory Argentine. Times of Minimum JD hel. E W (O - C) 243.... 8204.542 (S) -3343.5 1 -0.021 8228.465 -3313.5 1 +0.052 8263.395 -3269.5 1 +0.002 8267.336 -3264.5 1 -0.031 8295.222 -3229.5 1 +0.030 8314.276 -3205.5 1 +0.004 8316.278 -3203.0 1 +0.019 8555.549 -2902.0 1 -0.002 8641.402 -2794.0 1 -0.008 8649.311 -2784.0 1 -0.048 8992.401 -2352.5 1 +0.004 8994.412 -2350.0 1 +0.028 9029.333 -2306.0 1 -0.031 9374.375 -1872.0 1 -0.014 9376.374 -1869.5 1 -0.002 9378.372 -1867.0 1 +0.008 9380.374 -1864.5 1 +0.023 9404.252 -1834.5 1 +0.051 9654.198 -1520.0 1 -0.027 9656.198 -1517.5 1 -0.014 244.... 0064.049 -1004.5 1 +0.007 0068.021 (S) - 999.5 1 +0.004 0120.058 (E) - 934.0 1 -0.030 0120.083 - 934.0 1 -0.005 0120.933 - 933.0 1 +0.050 0122.888 - 930.5 1 +0.017 0124.005 - 929.0 1 -0.058 0124.010 - 929.0 1 -0.053 0124.016 - 929.0 1 -0.047 0440.037 (K) - 531.5 1 -0.034 0450.013 - 519.0 1 +0.004 0451.983 - 516.5 1 -0.013 0722.290 - 176.5 1 -0.002 0746.188 - 146.5 1 +0.046 0750.164 (K) - 141.5 1 +0.047 0862.6111 (W) 0.0 2 +0.0035 0862.6080 0.0 2 +0.0004 0862.6100 0.0 2 +0.0024 0863.8065 1.5 2 +0.0064 0863.8084 1.5 2 +0.0083 0863.8065 1.5 2 +0.0064 0864.6035 2.5 2 +0.0084 0864.6043 2.5 2 +0.0092 0864.6015 2.5 2 +0.0064 0870.5585 10.0 2 +0.0010 0870.5584 10.0 2 +0.0009 0870.5615 (W) 10.0 2 +0.0040 1122.146 (K) 326.5 1 -0.025 1587.6352 (L) 912.0 2 -0.0020 1587.6335 912.0 2 -0.0037 1587.6347 912.0 2 -0.0025 1589.6261 914.5 2 +0.0015 1589.6265 914.5 2 +0.0019 JD hel. 243.. . E W (O - C) 1589.6270 914.5 2 +0.0024 1592.8031 918.5 2 -0.0015 1592.8031 918.5 2 -0.0015 1592.8007 918.5 2 -0.0039 1606.7126 936.0 2 -0.0043 1606.7132 (L) 936.0 2 -0.0037 1606.7144 (L) 936.0 2 -0.0025 [FIGURE 1]