COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1009 Konkoly Observatory Budapest 1975 June 17 PHOTOGRAPHIC OBSERVATIONS OF EE CEPHEI AT THE 1969 MINIMUM From 1968 to 1970 we observed photographically a field centred on EE Cep. It has been accented that this star, discovered by Romano in 1952 to be a variable (1956, Coelum, 24, 135), is an eclipsing binary having a period of 2049 days. Minima were observed by Romano (1956), by Weber (1956, Pubbl.Spec.Ariel, 4; 1956, D.D.O., 9). by Romano and Perissinotto (1966, Mem.S.A.It., 37, 255) and by Meinunger (1973, M.V.S., 6, 89). We give here our observations carried out at the "G. Horn D'Arturo" observatory at Bologna (Baldinelli, 1972, Coelum, 40, 175) during the 1969 minimum. The photographs were taken at the prime focus of the 35 cm reflector of our observatory. The plates used were Ilford Zenith Astronomical with a 10 minutes exposure. For the work the plates were estimated visually by two observers, the mean difference being 0.05 mag., and by using the magnitude comparison sequence given by Romano (1956). The minimum was found to occur on J.D. 2440493 +- 1. The following table gives our observations near the period of this minimum. We also give the light-curve for the same minimum. ---------------------------------------------------------------------------- J.D. mag_pg J.D. mag_pg J.D. mag_pg J.D. mag_pg ---------------------------------------------------------------------------- 2440397 11.13 2440425 11.08 2440469 11.32 2440502 11.25 398 11.10 426 11.16 474 11.28 503 11.24 399 11.08 427 11.10 476 11.28 504 11.33 400 11.10 431 11.12 477 11.25 505 11.25 407 11.10 437 11.12 482 11.38 510 11.20 408 11.10 438 11.14 491 11.62 514 11.13 410 11.08 439 11.25 494 11.62 522 11.05 411 11.10 440 11.15 496 11.62 523 11.05 412 11.11 447 11.14 498 11.62 524 11.05 416 11.08 454 11.12 499 11.65 532 11.04 417 11.08 455 11.20 500 11.45 543 11.08 419 11.08 467 11.25 501 11.47 553 11.08 ----------------------------------------------------------------------------- [FIGURE 1] EE Cephei minimum light curve (1969) PHOTOGRAPHIC OBSERVATIONS OF EE CEPHEI AT THE 1975 MINIMUM We give here our observations carried out at the "G. Horn D'Arturo" observatory at Bologna (Baldinelli, 1972, Coelum, 40, 175) during the 1975 minimum. The photographs were taken at the newtonian focus of the 35 cm reflector of our observatory. The plates were Ilford Zenith Astronomical with a 10 to 20 minutes exposure. The plates were estimated by using the magnitude comparison sequence given by Meinunger (1975, IBVS, 965). The following table gives our observations near the period of this minimum. ----------------------------------------------------------- J.D. mag._ph No.of plates J.D. mag._ph No.of plates 2442000+ 2442000+ ----------------------------------------------------------- 525 11.1 1 543 12.6 6 530 11.3 2 547 12.6 4 531 11.2 4 548 12.2 6 532 11.2 3 549 12.2 4 533 11.2 2 550 12.0 7 534 11.3 4 551 11.8 2 535 11.3 2 552 11.5 2 542 12.6 3 ----------------------------------------------------------- MINIMA OF ECLIPSING VARIABLES The list below contains minima of eclipsing variables observed at the "G. Horn D'Arturo" observatory, at Tizzano, near Bologna. The observations were made with the 350 mm diam., f=180 cm newtonian reflector and an unrefrigerated photometer employing an 1P21 and V filter (UBV international system). The timings were reduced by the tracing paper method. ------------------------------------------------ Star J.D. hel. O-C N 2442.... ------------------------------------------------ W UMa 083.3801 -0.0060* 29 121.4141 -0.0067* 25 157.4480 -0.0058* 39 158.4485 -0.0062* 35 U CrB 245.9227 0.0212** *** ------------------------------------------------ * elements from SAC ** elements from GCVS *** normal minimum "G. Horn D'Arturo Observatory" presso Baldinelli L. BALDINELLI Montebello 4 S. GHEDINI I - 40121 Bologna C. TUBERTINI [From IBVS 1046] ERRATA-CORRIGE In the third page of the IBVS 1009 the O-C of the U CrB is. -0.0212^**, and not positive as published. LUIGI BALDINELLI