COMMISSION 27 OF THE I.A.U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 790 Konkoly Observatory Budapest 1973 May 9 AD LEO The photoelectric monitoring of the flare star AD Leo was carried out at the Okayama Station during the period of 27 January to 21 March 1973. The observations were made with the simultaneous three-color photometer attached to the 91 cm reflector. The observational results are summarized in the Table. Tokyo Astronomical Observatory April 10, 1973. K. OSAWA K. ICHIMURA. Y. SHIMIZU T. OKADA K. OKIDA M. YUTANI H. KOYANO Flares of AD Leo observed at Okayama, 27 to 31 January and 8 to 21 March 1973. ---------------------------------------------------------------------------------------------- Date Time of Filter Time of Flares 1973 Monitoring(UT) Max(UT) (I_0+f - I_0)/I_0 Max. P d_b d_a sigma Weather Delta m min min mag ---------------------------------------------------------------------------------------------- Jan. 27d 12h23m-14h35m U 7.69 2.35 0.9>15.8 B 15h23.2m 0.98 0.75 0.7>15.8 V 0.25 0.25 U>27.2min0.7>15.8 B> 3.9 U 3.07 1.53 V> 1.2 - U 0.12mag 1~4 14 57- 15 39 B 15 26.2 0.46 0.41 - B 0.04 V 0.13 0.14 - V 0.02 16 30- 18 23 U 1.34 0.92 >2.7 1.7 >5.4 B 18 04.1 0.22 0.21 >0.2 1.7 >5.4 3 V - - - - - - 28 13 37- 15 07 15 52- 19 55 U 1.87 1.11 >1.40 0.8 >2.2 0.14 4 B 19 28.1 0.17 0.20 >0.10 0.4 >0.8 0.05 V - - - - - - 0.02 29 11 35- 12 24 12 30- 12 53 30 12 05- 19 17 U 15 22.5 0.30 0.28 0.21 0.4 2.1 0.10 1 B 0.04 0.04 0.03 0.2 1.8 0.03 V - - - - - - 0.02 31 12 08- 19 53 U 0.65 0.54 0.77 0.6 4.1 0.11 B 17 02.6 0.10 0.10 0.11 0.6 3.2 0.03 0 V 0.03 0.03 0.04 0.4 2.4 0.02 Mar. 8 11 00- 16 43 U 0.73 0.60 1.00 0.7 5.1 0.10 B 13 51.7 0.18 0.18 0.25 1.1 5.7 0.03 1 V 0.03 0.03 0.03 0.8 1.4 0.01 U 0.95 0.73 1.21 0.4 5.0 0.12 B 16 05.5 0.11 0.11 0.08 0.3 3.7 0.04 1 V 0.04 0.04 0.04 0.4 1.8 0.02 U 3.80 1.70 >5.47 l.1 >2.6 0.13 B 16 40.4 0.70 0.58 >0.64 0.9 >2.4 0.03 3~4 V 0.12 0.12 >0.05 0.5 >0.7 0.02 10 10 40- 18 13 U 0,51 0.45 1.94 1.2 5.3 0.20 B 12 05.6 0.06 0.06 0.18 0.6 5.0 0.04 2 V 0.03 0.03 0.16 1.4 5.0 0.03 U 0.50 0.44 0.39 0.2 2.3 0.12 B 15 13.1 0.08 0.08 0.08 0.2 1.9 0.04 1 V - - - - - - 0.02 18 10 46- 14 31 U 13 33.2 1.12 0.82 0.30 0.2 0.4 0.44 1 B 0.21 0.21 0.04 0.2 0.2 0.08 V - - - - - - 0.02 19 11 44- 18 39 21 10 32- 11 18 U 0.85 0.67 0.58 0.2 2.0 0.16 1 B 11 03.8 0.08 0.08 0.03 0.3 0.5 0.04 V - - - - - - 0.02 12 58- 18 00 U 13 18.3 0.85 0.67 0.25 0.2 0.7 B 0.09 0.09 0.06 0.2 0.7 1 V - - - - - - 0.42 0.06 U 16 33.1 0.58 0.50 0.20 0.4 0.6 0.02 1 B 0.14 0.14 0.03 0.3 0.4 V - - - - - - ---------------------------------------------------------------------------------------------- Weather; 0=very clear, 1=clear, 2=some thin clouds, 4=some clouds.