COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 464 Konkoly Observatory Budapest 1970 September 10 PHOTOGRAPHIC OBSERVATIONS OF THE ECLIPSING VARIABLE HBV 434 = V 1171 Cyg This variable was discovered by Wachmann (A.A., Abh. Hamb.Sternw. VI, 4, 328 1966) during his survey of the Cygnus-Cloud. Although he observed 8 minima, no period could be found. Photoelectric observations obtained by the author during May and June 1969 gave 5 more minima. A weighted least-square-solution gave the following elements together with their mean errors: Min_hel = 244 0380.5492 + 1d462 123 9 ' E +- 95 +- 1 9 Table I gives the observed times of minimum, the epochs, their weights and the observer, Wa denoting Wachmann and Bo denoting the author. TABLE I. O E O-C P Obs. 243 3922.330 -4417.0 -0.021 1 Wa 4215.516 -4216.0 +0.009 1 Wa 4237.424 -4201.5 -0.015 1 Wa 4979.486 -3694.0 +0.020 1 Wa 4982.370 -3692.0 -0.020 1 Wa 5020.420 -3666.0 +0.014 1 Wa 5360.378 -3433.5 +0.029 1 Wa 5398.357 -3407.5 -0.007 1 Wa 244 0369.5695 -7.5 -0.0137 3 Bo 0372.5079 -5.5 +0.0004 5 Bo 0380.5527 0.0 +0.0035 10 Bo 0389.3114 +6.0 -0.0105 4 Bo 0394.4428 +9.5 +0.0035 10 Bo The normals of Table II were formed out of Wachmann's photographic observations, n giving their number. The total phase at primary minimum is not verified by the photoelectric observations. From Figure I the following characteristics of the light changes may by read: Max I : 10m.04 Min I : 10m32 Type : EA Max II : 10m.04 Min II : 10m28 [FIGURE 1] TABLE II. Phase m_pg n Phase m_pg n Phase m_pg n 0.0066 10.32 7 0.3219 10.03 10 0.6352 10.06 7 .0151 10.29 8 .3484 10.02 11 .6643 10.05 12 .0319 10.32 7 .3778 10.03 12 .6870 10.04 12 .0636 10.08 11 .3943 10.04 9 .7085 10.01 10 .0866 10.02 9 .4103 10.01 9 .7294 9.99 9 .1006 10.08 10 .4285 10.02 8 .7577 10.06 10 .1193 10.06 12 .4519 10.15 8 .7787 10.05 8 .1352 10.04 10 .4696 10.11 7 .8068 10.03 12 .1568 10.06 10 .4822 10.19 6 .8284 10.01 12 .1800 10.02 10 .4992 10.28 10 .8561 10.06 12 .1992 10.04 10 .5169 10.25 10 .8891 10.04 10 .2281 10.06 11 .5334 10.21 6 .9352 10.06 13 .2654 10.06 7 .5863 10.06 13 .9603 10.11 7 0.2947 10.00 9 0.6132 10.03 10 .9746 10.20 7 0.9944 10.32 5 V 1171 Cyg will be further observed with the 60 cm photoelectric telescope of Hamburg Observatory for the sake of finding orbital elements. The author is indebted to Prof. Dr.A.A. Wachmann for putting his photographic observations at the author's disposal. Hamburger Sternwarte, H.BOSSEN Germany