COMMISSION 27 OF THE I. A. U. INFORMATION BULLETIN ON VARIABLE STARS Number 1361 Konkoly Observatory Budapest 1977 November 7 SIX NEW RR LYRAE STARS IN NGC 1261 Periods for 13 RR Lyrae variables in NGC 1261 (alpha=13h10.9m, delta=-55d25", 1950; l=271d, b=-52d) were recently published by Wehlau and Demers (Astr.Astroph., 57, 251, 1977) using the same plate material as was used for the present paper. Fourteen pairs of the plates taken with the 60-cm telescope of the University of Toronto located on the site of the Las Campanas Observatory of the Hale Observatories were blinked at the University of Western Ontario and six new variables were discovered. Because all the new variables are close to the center of the cluster magnitudes had to be estimated by eye. Table 1 lists the estimates made from the plates available to Wehlau and Demers as well as estimates made by Bartolini from his plates (Bartolini et al., I.B.V.S. 662, 1972). All these values are strongly affected by blending on the plates. Estimates could not be made on plates of poorer quality, therefore less measures were available for period determination than were used in the previous study. All of the new variables appear to be RR Lyrae stars, bringing the number of known RR Lyrae variables in NGC 1261 to 19. Coordinates and light curve parameters are given in Table 2. For some variables the values of B_min, B_max, and B_mean are systematically too bright because of blending: Blue light curves for variables 16 and 21 are shown in Fig. 1 in which phase 0 corresponds to J.D.2442000. When measuring the coordinates for these stars it was discovered that incorrect coordinates for variable 4 are given in the Third Catalogue of Variable Stars in Globular Clusters (Sawyer Hogg, Publ. David Dunlap Obs. 3, No. 6, 1973). This can probably be attributed to an incorrect identification on the chart published by Fourcade et al. (Atlas y Catalogue de Estrellas Variables en Cumulos Globulares al sur de -29d, Cordoba, 1966). The correct values for variable 4 are X=+22.2 and Y=-31.8. There is an additional error in the sign of Y for variable 12 which should be +10.5. The addition of 4 more ab-type RR Lyrae stars brings the number known in this cluster to 14 and yields a value of of 0.555, only slightly lower than the value of 0.563 given in the earlier paper. Five c-type variables are now known in this cluster with a value of =0.328 hardly changed from the value of 0.323 given earlier. The ratio N_c/N_ab now stands at 0.36 well within the range expected for an Oosterhoff type I cluster. The authors would like to thank the National Research Council of Canada for its support of this research. A. WEHLAU, T. FLEMMING S. DEMERS C. BARTOLINI Department of Astronomy Departement de Observatorio University of Western physique Astronomico dell' Ontario, London Universite de Universita di Canada Montreal Bologna Montreal, P.Q., Canada Table 1 Heliocentric 16 17 18 19 20 21 J.D. 2440569.644 17.2 16.6 17.2 - 17.0 17.0 40569.662 16.5 17.1 17.1 - 16.1 17.3 40570.584 17.6 16.6 17.2 - 17.0 17.1 40570.690 17.6 17.1 17.3 - 17.2 17.2 40813.203 17.3 16.85 17.2 17.1 - 17.4 40814.180 17.3 - 17.2 16.4 - - 40837.072 16.7 16.8 17.0 16.0 - 17.2 40837.100 16.9 16.8 17.0 16.1 17.2 40837.173 17.1 16.8 17.1 16.3 - 16.8 40837.207 17.2 16.85 17.1 16.4 - 16.8 40837.233 17.3 16.65 17.1 16.55 - 16.9 40837.258 17.4 16.65 - 16.7 - 17.0 40841.219 16.4 - - 17.0 - 16.9 40841.244 16.4 - - 17.0 - 16.8 40841.270 16.5 - - 17.0 - 16.8 41299.543 15.9 16.5 17.0 16.4 16.5: 17.1 41300.550 16.7 16.5 16.8 16.0 16.3: 17.1 41301.551 17.1 16.6 16.8 16.6 16.0 16.9 41305.547 17.2 16.8 16.9 16.7 16.9 16.8 41625.852 17.2 16.6 17.6 17.0 16.7 17.0 41626.796 16.0 16.5 17.1 16.1 16.1 17.2 41627.694 17.4 17.0 17.0 16.5 - 17.2: 41627.722 17.3 16.8: 17.1 16.6 16.8: 17.2: 42327.707 16.2 16.7: 16.8 16.6 16.0 17.4 42327.748 16.8 16.8: 17.2 16.8 16.5 17.3 42327.789 17.0 17.0: 17.0 17.0 16,7 17.0 42327.807 16.8 17.1 17.6 16.8 16.8 16.9 42327.823 17.3 17.0 17.6 17.4 16.8 17.1 42328.739 16.0 16.6 17.2 17.6 16.7 17.2 42328.755 15.9 16.7: 17.1 17.5 16.2 17.2: 42328.803 16.7 17.0: 17.3 16.7 16.0 17.1 42329.779 15.9 16.5 17.3 16.7 16.9 17.1 42339.590 17.4 16.8: 17.2 16.7 16.0 16.9: 42340.575 17.3 16.7 17.0 17.1 17.1 16.9 42340.641 17.5 16.8 17.5 16.2 16.7 16.9 42392.703 17.5: 16.9: 17.0: - - 17.0: 42392.730 17.5: 16.5: 16.9: - 16.8: 42392.756 17.5: 16.4: 17.0: - - 17.1: 42393.540 16.4 17.2 17.1 16.8 16.8 17.4 42393.567 16.6 16.9 17.0 16.2 16.8 17.4 42393.594 17.1 17.1 16.9 16.0 16.9 17.4 42393.621 17.2 17.2 16.8 15.9 16.8 17.1 42393.661 17.2 17.1 17.1 16.3 16.8 17.0 42393.690 17.2 17.2 16.9 16.1 16.2 16.8 42393.717 17.5 16.9 17.1 16.4 15.9 16.8 42393.744 17.4 16.9 17.3 16.4 16.0 16.7 42394.641 17.0: - 16.9: - - 17.1: 42394.670 17.1: - 17.0: 16.5: - 17.0: 42394.706 17.3: - 16.6: 16.7: - 16.9 42394.733 17.3: - 17.0: 16.6: - 16.7 42395.542 15.8 16.9 17.1 16.3 16.8 17.3: 42395.569 16.2: 17.2: 17.2: 15.9: - 17.3 Table 1 ( cont.) Heliocentric 16 17 18 19 20 21 J.D. 2442395.648 16.6 17.2 16.8 16.3 16.8 17.3 42395.718 17.3: 17.1: 17.1: 16.3: - 17.1 42395.744 17.2: 17.1: 17.0: 16.5: - 17.1 42396.540 17.6: 17.0: 17.1: 16.8: - 17.4 42396.567 16.9 17.0 17.0 16.8 16.6 17.3 42396.639 16.2 17.1: 17.0: 16.7: - 17.2 Table 2 Var. X" Y" Type Period Epoch of Max.2400000+ B_min B_max B_mean 16 -17.7 -16.1 RRab 0.52618 42395.542 17.4 16.0 16.95 17 - 3.9 +20.1 RRab 0.51303 42392.756 17.1 16.5 16.85 18 -18.5 +16.7 RRc 0.33653 42395.648 17.5 16.9 17.1 19 +19.3 +11.9 RRab - 42395.718 17.4 16.0 16.6 20 +28.8 - 3.8 RRab 0.54123 42393.717 17.0 16.0 16.55 21 -12.5 +25.5 RRc 0.33441 42394.733 17.2 16.9 17.05 [FIGURE 1] [FIGURE 2]