NGC 6934 / C2031+072 (Updated September 2015) RA: 20:34:11.37 DEC: +07:24:16.1 (J2000) ============================================================ Bytes Format Explanation 1-8 A8 Star ID 10-32 A11,1x,A11 Position 34-35 A2 Units for position R0 denotes RA, DEC in the J2000 coordinates R5 denotes RA, DEC in the 1950 coordinates XA denotes X, Y in arcseconds XP denotes X, Y in pixels 37-44 F8.4 Period (days) 46-51 F6.3 Mean magnitude (or maximum magnitude if "max" is indicated in the remarks column) 53-57 F5.3 Light amplitude (range of variability) 59 A1 Colour for mean magnitude and amplitude e.g. B, V, R, I, J, K or P (for photographic). 61-65 A5 Type of variable (draft 2006 GCVS classifications) CST denotes non variable stars previously designated as variables 67-80 A19 Notes and Remarks (f denotes field star) "--" or "----" indicates no data available ========================================================================= ID Position Period ampl C Type Notes/ RA/X Dec/Y Units Remarks ========================================================================= 1 20:34:08.4 07:23:39 R0 0.5675 16.92 0.60 V RR0 2 20:34:08.6 07:24:02 R0 0.4819 16.90 1.03 V RR0 3 20:34:11.4 07:25:15 R0 0.5398 16.85 1.09 V RR0 4 20:34:13.9 07:25:15 R0 0.6164 16.69 1.10 V RR0 5 20:34:15.2 07:27:58 R0 0.5646 17.01 0.81 V RR0 6 20:34:09.5 07:23:45 R0 0.5559 16.96 1.03 V RR0 7 20:34:17.4 07:25:16 R0 0.6440 16.82 0.68 V RR0 8 20:34:18.0 07:25:08 R0 0.6240 16.95 0.60 V RR0 9 20:34:15.6 07:24:36 R0 0.5492 16.89 0.97 V RR0 10 20:34:02.2 07:25:28 R0 0.5200 16.94 1.30 V RR0 11 20:34:12.5 07:24:46 R0 0.3087 16.88 0.50 V RR1 12 20:34:13.2 07:23:34 R0 0.4642 16.95 1.11 V RR0 13 20:34:08.1 07:24:42 R0 0.5513 16.94 0.87 V RR0 14 20:34:10.9 07:22:47 R0 0.5220 16.85 1.00 V RR0 15 20:34:11.95 07:23:25.3 R0 --- 15.95 0.75 P SR? Note 16 20:34:13.7 07:24:36 R0 0.6049 16.90 0.77 V RR0 17 20:34:06.5 07:22:30 R0 0.5983 16.91 0.70 V RR0 18 20:34:14.6 07:24:09 R0 0.9561 16.50 0.47 V RR0 19 20:34:13.2 07:24:19 R0 0.4805 -- -- V RR0 20 20:34:09.6 07:24:34 R0 0.5483 16.78 1.02 V RR0 21 20:34:08.9 07:24:15 R0 0.5268 16.94 0.69 V RR0 22 20:33:55.3 07:21:24 R0 0.5743 16.93 0.50 V RR0 23 20:34:09.3 07:24:00 R0 0.2846 -- -- RR1 24 20:34:13.8 07:23:24 R0 0.6417 16.94 0.46 V RR0 25 20:34:14.7 07:24:54 R0 0.5091 16.88 1.01 V RR0 26 20:34:13.4 07:21:02 R0 0.2593 16.96 0.39 V RR1 27 20:34:01.4 07:27:39 R0 0.5922 16.88 0.84 V RR0 28 20:33:55.6 07:25:56 R0 0.4852 16.87 1.31 V RR0 29 20:34:05.7 07:21:14 R0 0.4548 17.08 1.32 V RR0 30 20:34:22.1 07:26:26 R0 0.5899 16.92 0.79 V RR0 31 20:34:21.1 07:22:37 R0 0.5051 16.95 1.20 V RR0 32 20:34:10.6 07:25:08 R0 0.5119 16.84 1.23 V RR0 33 20:34:13.8 07:24:29 R0 0.5184 16.97 1.32 V RR0 34 20:34:09.9 07:24:32 R0 0.5601 16.82 0.97 V RR0 35 20:34:21.9 07:21:56 R0 0.5442 16.99 0.76 V RR0 36 20:34:12.1 07:23:41 R0 0.4957 16.89 1.19 V RR0 37 20:34:12.9 07:24:28 R0 0.5332 16.87 1.20 V RR0 38 20:34:12.2 07:23:59 R0 0.5236 16.71 1.04 V RR0 39 20:34:11.9 07:24:00 R0 0.5026 16.73 1.06 V RR0 40 20:34:10.7 07:24:44 R0 0.5608 16.81 0.96 V RR0 41 20:34:13.3 07:23:38 R0 0.5204 16.94 1.10 V RR0 42 20:34:15.0 07:24:39 R0 0.5242 16.95 1.21 V RR0 43 20:34:12.8 07:24:45 R0 0.5632 16.83 0.92 V RR0 44 20:34:08.5 07:23:48 R0 0.6304 16.90 0.50 V RR0 45 20:34:09.2 07:24:08 R0 0.5366 16.97 1.35 V RR0 Note 46 20:34:12.3 07:23:53 R0 0.3286 16.76 0.41 V RR1 47 20:34:12.0 07:23:52 R0 0.6409 16.81 0.48 V RR0 48 20:34:13.5 07:25:08 R0 0.5613 16.88 0.93 V RR0 49 20:34:12.2 07:23:22 R0 0.2855 16.80 0.50 V RR1 50 20:34:12.4 07:23:41 R0 0.6345 16.88 0.47 V RR0 51 20:34:11.8 07:24:52 R0 0.5648 16.73 0.80 V RR0 52 20:34:18.3 07:22:14 R0 0.0598 18.92 0.46 V SXPHE 53 20:34:13.6 07:24:00 R0 0.2824 16.88 0.49 V RR1 54 20:34:12.6 07:24:35 R0 0.5902 16.79 0.73 V RR0 55 20:34:13.3 07:24:27 R0 0.7783 16.66 0.25 V RR0 Note 56 20:34:12.5 07:24:18 R0 0.2910 16.64 0.46 V RR1 57 20:34:12.4 07:24:10 R0 0.6871 -- -- RR0 58 20:34:12.1 07:25:05 R0 0.4008 16.69 0.47 V RR1 59 20:34:12.0 07:24:15 R0 0.5386 -- -- RR0 60 20:34:12.0 07:24:56 R0 0.6604 16.85 0.40 V RR0 61 20:34:11.9 07:23:10 R0 ---- 16.87 0.38 V RR? Note 62 20:34:11.7 07:24:26 R0 0.5307 -- -- V RR0 63 20:34:11.6 07:24:26 R0 0.5756 -- -- V RR0 64 20:20:11.4 07:24:18 R0 0.5710 -- -- V RR0 65 20:34:11.4 07:24:15 R0 0.6590 -- -- V RR0 66 20:34:11.1 07:24:16 R0 0.5408 -- -- V RR0 67 20:34:10.9 07:23:55 R0 0.6133 -- -- V RR0 68 20:34:10.9 07:24:00 R0 0.3353 -- -- V RR1 69 20:34:10.8 07:23:15 R0 0.2470 16.90 0.09 V RR1? RR2? 70 20:34:10.7 07:24:06 R0 0.5393 -- -- V RR0 71 20:34:10.7 07:23:54 R0 0.5727 -- -- V RR0 72 20:34:10.5 07:25:20 R0 0.6679 16.85 0.29 V RR0 73 20:34:09.8 07:24:47 R0 0.5062 16.92 0.51 V RR0 74 20:34:09.3 07:24:08 R0 0.5681 16.86 1.00 V RR0 Note 75 20:34:02.8 07:19:35 R0 0.2821 17.15 0.36 V EW f;Note 76 20:33:54.6 07:19:50 R0 0.3365 17.94 0.31 V EW f;Note 77 20:34:10.5 07:24:24 R0 ---- 19.10 -- V L f?;Note 78 20:34:12.1 07:24:38 R0 0.5423 -- -- V RR0 79 20:34:10.5 07:24:24 R0 0.6219 -- -- RR0 Note 80 20:34:11.7 07:24:07 R0 0.5443 16.77 -- V RR0 81 20:34:11.2 07:24:23 R0 0.5726 -- -- RR0 82 20:34:10.7 07:24:17 R0 0.7311 -- -- RR0 83 20:34:11.2 07:24:26 R0 0.5405 -- -- RR0 84 20:34:12.1 07:24:28 R0 0.6654 -- -- RR0 85 20:34:31.0 07:21:57 R0 1.6220 17.46 0.13 V ? AltP=2.606 86 20:34:19.4 07:22:51 R0 49.0 13.90 0.15 V SR =================================================================== Supplementary Notes NGC 6934 is an intermediate-metallicity cluster with [Fe/H]=-1.47 according to the 2010 update of the Harris (1996) catalogue. A BV CM diagram by Piotto et al. (1999), based on HST observations, shows a well populated HB with an extended blue HB and a well defined sequence of blue stragglers. The most extensive investigation of the variable stars was by Kaluzny et al. (2001). All of the data in the above table are from their study unless indicated otherwise in the Notes on individual stars. =================================================================== Notes on individual stars V15: This star was not studied by Kaluzny et al. (2001). The RA and dec are from Samus et al. (2009). Harris & Racine (1973) showed that V15 is located near the RG tip in the CM diagram and classified it as a possible semi-regular or long period variable. The magnitudes in the above table are from Sawyer Hogg & Wehlau (1980). V45, V74: Kaluzny et al. (2001) listed coordinates for these two strs that indicated a difference of only 0.1 seconds in RA (less than 2 arcseconds). However, their finder charts indicate that the separation is about 10 seconds of arc. V55: Samus et al. (2009) commented that the chart publsihed for V55 by Kaluzny et al. (2001) was discrepant. V61: Kaluzny et al. (2001) derived a period of 0.528 days for this star but noted that it was very uncertain. There was a lot of scatter on the light curve. Its magnitude and colour are similar to those of the RR Lyrae variables. It could be a star that manifests a strong Blazhko effect or even double mode pulsation. V75, V76: Kaluzny et al. (2001) applied a technique devised by Rucinski (2000) for establishing the membership status of EW variables. They concluded that neither of these stars is a cluster member. Samus et al. (2009) noted that they have been listed in the Moscow GCVS as OP Del and OO Del respectively. They also pointed out that the chart for V76 published by Kaluzny et al. (2001) was discrepant. V77, V79: Kaluzny et al. (2001) published exactly the same coordinates for these two stars. However, their finder charts do not indicate that the stars lie at the same position. If the published magnitudes for the long period variable V77 are correct, the location on the CM diagram indicates that V77 is not a cluster member. Another puzzling feature of these two stars is that Kaluzny et al. (2001) were able to derive magnitudes and colours for V77, but not for V79. =================================================================== Discovery of the variable stars in NGC 6934: V1-51 Sawyer, H. B. (1938) with x,y coordinates and an ID chart Preliminary results were announced by Sawyer (1933, 1936) V52-86 Kaluzny et al. (2001) with RA, dec and indiviual finder charts ==================================================================== References Harris, W. E. 1996, AJ, 112, 1487 Harris, W. E. & Racine, R. 1973, AJ, 78, 242 Kaluzny, J., Olech, A., Stanek, K. Z. 2001, AJ, 121, 1533 Piotto, G., Zoccali, M., King, I. R., Djorgovski, S. G., Sosin, C., Dorman, B., Rich, R. M., Meylan, G. 1999, AJ, 117, 264 Rucinski, S. M. 2000, AJ, 120, 319 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Sawyer, H. B. 1933, Pub. AAS, 7, 185 Sawyer, H. B. 1936, Pub. AAS, 8, 149 Sawyer, H. B. 1938, Dominion Astrophys. Obs. Publ., 7, 121 (1938) Sawyer Hogg, H. & Wehlau, A. 1980, AJ, 85, 148 =====================================================================