COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS NUMBER 317 Konkoly Observatory Budapest 1968 December 3 PHOTOELECTRIC OBSERVATIONS OF UV Ceti During the UV Ceti international patrol, planned for 1968 by Working Group on Flare Stars, we carried out continous photoelectric monitoring of this star with the 91 cm cassegrain telescope at our stellar station in Serra La Nave (Catania). The same photometer was used as for the observations of YZ CMi (IBVS no 274). From October 11 to October 28 we have made about 50h.0 of patrol in thirteen nights. The photoelectric coverage is given in Tab.I. The patrol times do not include the sky measurements. For the time intervals enclosed under uncertain coverage, we can only exclude the happening of flares greater than 0.3m. This is due to the bad quality of the seeing. The characteristics of 64 observed flares are reported in Tab.II. The times d and D are the rise time and the total duration of the flare, respectively. The times d' and D' are both referred to that part of the flare for which we have: I_flare/I_min >= 20% I_flare_max/I_min Some more details will be published in the "Memorie della Societa Astronomica Italiana". CRISTALDI S., NARBONE M., RODONO M. Osservatorio Astrofisico Catania (Sicily) Tab I. Photoelectric Coverage (October 1968) Number of observed N Day Coverage Uncertain flares coverage certain uncertain 1 11 1h54.8m 1h00.2m 2 - 2 13 3 40.0 30.8 - 2 3 13 3 57.1 - 6 3 4 14 6 28.7 4.3 4 - 5 15 6 24.3 4.9 4 2 6 19 6 10.3 1.5 10 5 7 17 5 15.3 3.0 3 - 8 18 6 51.7 - 7 3 9 23 2 06.5 - 2 1 10 24 1 01.4 35.4 2 - 11 27 2 02.4 6.8 4 - 12 28 4 06.3 39.1 4 - 49h59.1m 3h06.0m 48 16 Tab II Characteristics of the Observed Flares (October 1968) No. Day d D d' D' I_max/I_min Remarks 1 11 0.50m 1.60m 0.28m 0.80m 2.30 2 0.40 10.00 0.28 2.50 1.79 3 12 0.15 0.85 0.10 0.48 1.46 (1) 4 0.20 5.00 0.08 2.50 1.52 (1) 5 13 0.10 5.00 0.09 1.13 2.25 6 2.27 7 0.10 2.00 0.09 1.10 1.48 8 2.31 9 0.10 4.15 0.07 1.32 2.07 10 0.05 1.20 0.04 0.75 1.38 (1) 11 0.05 3.70 0.04 0.30 1.64 (1) 12 0.05 0.50 0.04 0.40 1.48 (1) 13 0.05 1.70 0.04 0.28 3.06 14 14 0.10 1.70 0.08 0.80 1.67 15 1.69 (2) 19 1.71 (2) 17 0.10 1.50 0.08 0.43 1.77 18 15 1.43 (2) 19 2.20 (2) 20 1.76 (2) 21 0.05 1.40 0.04 0.68 1.15 (1) 22 0.80 4.70 0.65 3.83 1.13 23 1.63 (1) (2) 24 16 0.05 0.60 0.04 0.58 1.22 (1) 25 1.51 (2) 26 1.28 (2) 27 0.05 0.20 0.03 0.13 1.25 (1) 28 0.20 0.50 0.10 0.28 1.18 (1) 29 0.10 0.70 0.08 0.30 1.21 (1) 30 1.49 (2) 31 0.10 1.10 0.09 0.17 1.67 32 1.29 (1) (2) 33 0.15 0.60 0.12 0.20 1.32 34 0.05 0.70 0.04 0.50 1.58 35 1.76 (2) 36 1.58 (2) 37 0.20 4.10 0.17 0.60 1.60 38 0.15 2.10 0.08 0.35 1.75 39 17 0.10 1.00 0.08 0.50 1.68 40 0.00 0.40 0.00 0.22 1.51 41 0.10 0.10 0.08 0.45 1.84 42 18 0.20 3.20 0.13 0.72 1.43 43 1.10 2.00 0.60 1.00 1.18 (1) 44 0.45 1.30 0.35 1.00 1.17 (1) 45 1.46 (1) 46 1.73 (2) 47 2.07 (2) 48 1.53 (2) 49 0.30 6.20 0.25 3.40 1.41 50 1.59 (2) 51 4.47 (2) 52 23 0.20 1.50 0.07 0.62 1.63 53 0.60 1.10 0.20 0.70 1.20 (1) 54 0.60 2.50 0.50 1.65 1.30 55 24 0.05 1.80 0.05 0.11 2.02 56 0.30 0.50 0.09 0.20 1.80 57 27 1.51 (2) 58 0.05 1.35 0.05 0.50 1.49 59 0.20 1.90 0.19 0.50 1.57 60 1.44 (2) 61 28 0.15 0.40 0.14 0.22 2.10 62 1.96 (2) 63 1.29 (2) 64 0.10 1.80 0.08 0.95 1.42 Remarks: (1) uncertain; (2) complex structure.