COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 906 Konkoly Observatory Budapest 1974 July 4 PHOTOELECTRIC OBSERVATIONS OF THE FLARE STARS AD Leo AND WX UMa (1974) Continual photoelectric monitoring of the flare stars AD Leo and WX UMa were carried out at the Okayama Station of the Tokyo Astronomical Observatory. The observations were made with the simultaneous three-colour photometer attached to the 91 cm reflector. AD Leo During the 28 hours of monitoring in total, 10 flares were observed. The detailed coverages are given in Table I. The characteristics of the flares are given in Table II. WX UMa During the 12.3 hours of monitoring in total, no flare activity was detected. The detailed coverages are given in Table I. Some more details will be published in the Tokyo Astronomical Bulletin. Table I Monitoring of AD Leo and WX UMa Monitoring Intervals Date Total Coverage sigma (mag) 1974 Coverage (UT) Time U B V Feb. AD Leo 13d 11h24m- 17h11 5h47m .09 .03 .01 14 12 35 - 16 25 3 50 .05 .01 .01 16 11 46 - 14 10 2 24 .10 .04 .02 17 13 25 - 20 20 6 55 .09 .03 .01 18 10 59 - 19 10 8 11 .07 .04 .02 21 11 10 - 11 30 0 56 .12 .07 .04 12 56 - 13 32 Apr. WX UMa 23 16 57 - 17 49 0 52 .15 .04 .02 26 11 22 - 16 31 5 09 .19 .04 .02 27 11 01 - 11 30 1 56 .16 .03 .01 12 15 - 14 11 29 10 58 - 15 23 4 25 .12 .04 .01 Table II Flares of AD Leo at Okayama (I_{0+f}- Flare Time of Max. Filter -I_0)/I_0 delta{m} P d_b d_a No. (UT) mag. min min min 1 1974 Feb.13d14h06m.5 U 2.86 1.47 4.3 0.4 6.7 B 0.33 0.31 0.6 0.4 6.5 V 0.12 0.12 0.2 0.5 6.0 2 13 15 55.3 U 2.94 1.49 1.5 0.3 4.5 B 0.39 0.36 0.2 0.3 4.0 V 0.12 0.12 <0.1 0.3 1.1 3 13 16 55.0 U 1.42 0.96 2.7 1.1 >6.0 B 0.14 0.14 0.2 1.1 >3.5 V 0.03 0.03 <0.1 0.9 1.6 4 14 15 38.4 U 1.25 0.88 4.6 2.7 8.0 B 0.14 0.14 0.3 2.3 5.0 V 0.02 0.02 * * * 5 17 14 34.7 U 5.19 1.98 4.0>180.0 B 0.61 0.52 3.0>180.0 V 0.20 0.20 2.5>180.0 6 17 14 35.9 U 6.80 2.23 B 0.80 0.64 V 0.27 0.26 7 17 14 40.3 U 5.08 1.96 B 0.66 0.55 for Nos. 5-10: V 0.24 0.23 U>1318 B> 230 8 17 15 01.4 U 100.00 5.01 V> 65 B 13.86 2.93 V 3.57 1.65 9 17 16 02.4 U 7.09 2.27 B 1.11 0.81 V 0.50 0.44 10 17 16 03.8 U 7.32 2.30 17 16 03.6 B 1.07 0.79 V 0.47 0.42 Tokyo Astronomical Observatory 15 June, 1974 K. OSAWA K. ICHIMURA Y. SHIMIZU H. KOYANO