NGC 6402 / C1735-032 / Messier 14 RA: 17:37:36.10 DEC: -03:14:45.3 (J2000) (Most recent updates: Membership probability flag - 2024; Remaining data - June 2022) ============================================================ Bytes Format Explanation 1-8 A8 Star ID 10-32 A11,1x,A11 Position 34-35 A2 Membership probability flag based on data published by Prudil & Arellano Ferro (2024) m1: prob >=0.85; m2: prob >=0.7 and <0.85; m3: prob >= 0.5 and <0.7; f: prob <0.5 u: no data available 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 Mem Period ampl C Type Notes/ RA Dec Flag Remarks ========================================================================= 1 17:37:37.39 -03:13:59.5 m1 18.7602 14.210 1.24 V CW Note 2 17:37:28.62 -03:16:45.3 m1 2.7947 15.629 0.88 V CW 3 17:37:36.09 -03:16:14.5 u 0.5224 16.734 0.42 V RR0 Note 4 17:37:47.02 -03:13:31.9 m1 0.6513 17.177 0.93 V RR0 5 17:37:27.20 -03:13:17.8 m1 0.5488 17.195 1.19 V RR0 6 17:37:38.59 -03:16:02.3 m1 ---- 14.5 -- V SR 7 17:37:40.43 -03:16:20.5 m1 13.6038 14.745 0.88 V CW 8 17:37:42.64 -03:14:09.5 m1 0.6861 17.213 0.54 V RR0 9 17:37:46.39 -03:15:23.8 m1 0.5388 17.262 1.06 V RR0 10 17:37:33.01 -03:18:09.7 m1 0.5859 17.137 1.10 V RR0 11 17:37:49.36 -03:18:26.1 f 0.6044 16.686 1.21 V RR0 f 12 17:37:51.31 -03:17:40.6 m1 0.5040 17.193 1.27 V RR0 13 17:37:34.43 -03:16:44.0 f 0.5352 17.060 0.74 V RR0 14 17:37:39.81 -03:14:48.1 m1 0.4721 17.276 1.34 V RR0 15 17:37:27.31 -03:12:19.2 m1 0.5577 17.124 1.19 V RR0 16 17:37:31.03 -03:15:21.8 f 0.6006 17.001 0.81 V RR0 17 17:37:21.08 -03:12:45.0 m1 12.091 14.676 0.61 V CW 18 17:37:40.46 -03:15:07.2 m1 0.4791 17.237 1.09 V RR0 19 17:37:27.79 -03:14:44.3 m1 0.5457 17.172 1.19 V RR0 20 17:37:26.57 -03:13:08.6 m1 0.2635 17.288 0.49 V RR1 21 17:37:41.02 -03:12:40.2 m1 0.3189 17.012 0.45 V RR1 22 17:37:40.94 -03:13:10.6 m1 0.6559 17.216 0.90 V RR0 23 17:37:41.18 -03:10:05.0 m1 0.5523 17.053 0.99 V RR0 Note 24 17:37:36.14 -03:13:30.6 f 0.5199 17.212 1.30 V RR0 25 17:37:34.56 -03:19:57.8 m1 0.3607 17.145 0.40 V RR1 Note 26 17 37 30.59 -03 14 17.3 m1 ---- -- -- CST 27 17 37 08.10 -03 12 17.5 m1 302.3155 14.29 0.31 V SR Note 28 17 37 05.03 -03 08 37.4 u 0.6568 15.1 0.9 V EA f;Note 29 17:37:31.76 -03:17:16.2 m1 ---- 14.1 -- V SR 30 17:37:41.31 -03:14:57.1 m1 0.5342 17.163 1.22 V RR0 31 17:37:33.64 -03:14:14.1 m3 0.6196 17.139 0.94 V RR0 32 17:37:38.57 -03:12:18.8 m1 0.6560 16.978 0.86 V RR0 33 17:37:27.03 -03:14:32.2 m1 0.4799 17.308 1.01 V RR0 34 17:37:31.56 -03:14:19.2 m1 0.6066 17.230 0.75 V RR0 35 17:37:28.83 -03:15:33.9 m1 ---- -- -- CST Note 36 17:37:50.05 -03:20:29.2 m1 0.6780 17.000 0.68 V RR0 37 17:37:36.69 -03:14:27.1 f 0.4891 17.115 0.92 V RR0 38 17:37:36.99 -03:15:02.7 m1 0.5085 17.170 1.12 V RR0 39 17:37:39.33 -03:14:45.8 m1 0.5760 17.168 1.25 V RR0 40 17 37 53.03 -03 09 32.2 f ---- -- -- CST 41 17:37:35.11 -03:14:47.3 f 0.2592 17.344 0.43 V RR1 42 17:37:38.70 -03:14:33.3 m2 0.6311 16.825 0.67 V RR0 43 17:37:40.70 -03:14:22.9 m1 0.5217 17.432 1.26 V RR0 Note 44 17:37:37.51 -03:12:47.7 m3 0.2894 17.118 0.43 V RR1 45 17:37:30.18 -03:13:12.7 m1 ---- 14.4 -- V SR Note 46 17:37:42.31 -03:15:49.7 m1 0.3326 17.283 0.51 V RR1 47 17:37:30.28 -03:14:18.7 m1 0.8770 17.054 0.44 V RR0 48 17:37:35.84 -03:14:04.9 m1 0.4685 17.556 1.15 V RR0 49 17:37:29.87 -03:15:04.5 f 0.6415 16.913 0.54 V RR0 f 50 17:37:35.21 -03:15:23.8 m1 ---- -- -- CST Note 51 17:37:43.37 -03:19:50.1 m1 0.2688 17.185 0.35 V RR1 Note 52 17:37:41.70 -03:14:06.6 m1 ---- -- -- CST 53 17:37:45.09 -03:12:34.7 m1 ---- -- -- CST 54 17:37:44.36 -03:12:51.6 f ---- -- -- CST 55 17:37:38.44 -03:12:59.0 m1 0.3375 17.217 0.41 V RR1 56 17:37:31.87 -03:17:48.8 m1 0.3411 17.075 0.41 V RR1 57 17:37:45.26 -03:16:39.4 m1 0.5669 17.257 0.74 V RR0 58 17:37:28.12 -03:15:19.3 m1 0.4179 17.052 0.43 V RR1 59 17:37:34.15 -03:14:16.2 m1 0.5566 17.334 0.83 V RR0 60 17:37:39.05 -03:13:50.4 f 0.5789 17.590 1.04 V RR0 61 17:37:37.20 -03:15:28.4 f 0.5698 17.438 0.85 V RR0 62 17:37:20.92 -03:17:20.7 m1 0.6385 17.273 0.37 V RR0 63 17:37:44.53 -03:15:46.5 f ---- -- -- CST 64 17:37:32.97 -03:17:34.5 m1 ---- -- -- CST 65 17:37:27.93 -03:14:32.4 m1 ---- -- -- CST 66 17:37:27.45 -03:14:08.9 m1 ---- -- -- CST 67 17:37:38.51 -03:14:31.5 m1 ---- -- -- CST 68 17:37:36.91 -03:15:05.2 f 0.5072 17.209 1.19 V RR0 69 17:37:45.58 -03:14:16.9 m1 ---- -- -- CST 70 17:37:39.12 -03:15:07.7 m2 0.6038 17.219 1.12 V RR0 71 17:37:28.63 -03:15:35.7 m1 0.5267 17.247 0.95 V RR0 Note 72 17 37 44.50 -03 16 44.5 m1 ---- -- -- CST 73 17:37:36.57 -03:14:38.0 m1 ---- 15.5 -- V SR/L? 74 17:37:36.71 -03:13:14.7 m1 ---- 14.6 -- V SR 75 17:37:38.62 -03:14:55.5 m1 0.5453 17.036 1.05 V RR0 76 17:37:29.25 -03:14:45.0 m1 1.8903 15.978 0.52 V CW 77 17:37:29.00 -03:13:47.5 m1 0.7922 17.090 0.45 V RR0 78 17:37:27.17 -03:14:48.5 m1 0.3103 17.244 0.41 V RR1 79 17:37:35.54 -03:15:00.4 m1 0.5599 17.320 1.11 V RR0 80 17:37:33.98 -03:17:14.5 m1 0.3158 17.103 0.41 V RR1 81 17 37 33.75 -03 17 06.6 m1 ---- -- -- CST 82 17 37 30.99 -03 16 48.1 m1 ---- -- -- CST 83 17 37 31.84 -03 15 19.8 m1 ---- -- -- CST 84 17 37 33.25 -03 15 23.4 m1 ---- -- -- CST 85 17 37 34.91 -03 13 52.6 m1 ---- -- -- CST 86 17:37:40.83 -03:14:21.6 m1 ---- -- -- CST Note 87 17 37 31.23 -03 14 31.2 m1 ---- -- -- CST 88 17:37:31.05 -03:14:33.1 m1 0.3131 17.412 0.45 V RR1 89 17 37 35.05 -03 15 18.4 u ---- -- -- CST 90 17:37:33.71 -03:15:16.4 m2 0.3513 17.114 0.38 V RR1 91 17:37:29.87 -03:15:21.5 m1 0.2613 17.317 0.37 V RR1 92 17:37:33.83 -03:14:41.2 f 0.6577 17.415 0.48 V RR0 93 17 37 35.10 -03 14 47.4 f ---- -- -- CST 94 17:37:23.04 -03:14:50.5 u ---- -- -- CST? Note 95 17:37:24.42 -03:17:29.4 m1 0.3595 17.139 0.40 V RR1 96 17:37:24.92 -03:14:47.6 m1 0.2525 17.312 0.38 V RR1 97 17:37:25.27 -03:18:37.1 f 0.3774 15.243 0.49 V EC f 98 17:37:26.00 -03:12:49.4 m1 0.2578 17.258 0.40 V RR1 99 17:37:26.78 -03:14:47.5 m1 ---- 14.6 -- V SR 100 =V91 101 17:37:30.28 -03:15:52.7 u ---- -- -- CST? Note 102 17:37:31.50 -03:16:01.1 m1 ---- 14.7 -- V SR 103 17:37:32.48 -03:14:12.5 u ---- -- -- CST? Note 104 17:37:32.88 -03:14:56.3 u 0.2622 16.691 0.20 V RR1 105 17:37:33.14 -03:14:03.7 m1 0.2794 17.489 0.51 V RR1 106 17:37:33.48 -03:14:46.8 m1 0.5470 17.581 1.15 V RR0 107 17:37:33.75 -03:14:48.5 m1 0.2950 17.667 0.55 V RR1 108 17:37:33.62 -03:15:12.0 m1 ---- -- -- CST? Note 109 =V92 110 17:37:33.87 -03:16:10.2 m1 0.3012 17.255 0.43 V RR1 111 =V172? 112 =V80 113 17:37:33.91 -03:14:27.5 u ---- -- -- CST? Note 114 17:37:34.10 -03:14:53.0 m1 0.3324 16.379 0.11 V RR1 115 17:37:33.95 -03:14:24.1 u ---- -- -- CST? Note 116 17:37:34.24 -03:15:37.8 m1 0.2521 17.695 0.37 V RR1 117 17:37:34.29 -03:14:36.4 m1 0.3395 17.265 0.49 V RR1 118 17:37:34.46 -03:16:13.0 m1 0.3805 16.989 0.33 V RR1 119 17:37:34.63 -03:14:52.3 m3 0.3326 16.830 0.24 V RR1 120 17:37:34.79 -03:13:30.8 m1 0.331 17.607 0.62 V RR1 121 17:37:35.22 -03:15:20.0 f 0.2712 16.496 0.12 V RR1 122 17:37:35.48 -03:14:39.4 f 0.5579 16.726 0.55 V RR0 123 17:37:35.74 -03:15:44.1 f 0.2842 17.549 0.30 V RR1 124 17:37:35.93 -03:15:27.5 f 0.5699 17.417 0.85 V RR0 Note 125 17:37:35.79 -03:15:15.1 u ---- -- -- CST? Note 126 17:37:36.03 -03:14:53.5 f 0.2942 16.145 0.13 V RR1 127 17:37:36.09 -03:14:33.0 m1 0.2985 15.923 0.24 V RR1 128 17:37:36.12 -03:13:52.9 m1 0.3927 17.299 0.36 V RR1 129 17:37:36.30 -03:15:01.3 m1 0.2799 17.650 0.39 V RR1 130 17:37:36.46 -03:15:25.2 m1 0.5958 17.216 0.59 V RR0 131 17:37:36.46 -03:14:54.3 u 0.2697 16.695 0.23 V RR1 132 17:37:36.73 -03:15:14.5 m1 0.4815 17.175 1.01 V RR0 133 17:37:36.88 -03:18:15.1 m1 0.3030 17.168 0.45 V RR1 134 =V68 135 17:37:37.00 -03:13:42.1 m1 0.3385 17.327 0.46 V RR1 136 17:37:37.02 -03:15:24.2 m1 0.3301 17.128 0.44 V RR1 137 17:37:37.67 -03:14:40.5 f 0.2762 16.899 0.26 V RR1 138 17:37:38.12 -03:15:32.7 m2 0.3712 16.995 0.39 V RR1 139 17:37:38.22 -03:17:23.0 m1 0.2720 17.448 0.57 V RR1 140 17:37:38.41 -03:15:51.4 m1 0.7609 17.171 0.44 V RR0 141 17:37:38.49 -03:14:27.1 m1 0.6432 17.112 0.89 V RR0 142 17:37:38.90 -03:14:01.9 f 0.4617 17.200 1.09 V RR0 143 17:37:39.03 -03:16:30.5 m1 0.3185 17.352 0.44 V RR1 144 17:37:39.45 -03:14:29.2 f 0.3756 17.207 0.41 V RR1 145 17:37:40.16 -03:15:00.9 f 0.3003 17.362 0.40 V RR1 146 17:37:40.16 -03:16:08.6 m1 ---- -- -- CST? Note 147 17:37:40.45 -03:15:54.9 m1 0.4928 17.031 1.15 V RR0 148 17:37:40.95 -03:16:59.3 m1 0.2652 17.309 0.32 V RR1 149 =V23 150 17:37:41.31 -03:14:07.6 m1 0.8028 17.136 0.54 V RR0 151 17:37:41.36 -03:14:22.1 m1 0.3197 17.438 0.37 V RR1 Note 152 17:37:42.08 -03:15:36.3 m1 ---- 14.4 -- V SR? 153 17:37:42.12 -03:11:55.7 m1 0.2648 17.193 0.29 V RR1 154 17:37:42.70 -03:13:58.8 m1 0.2550 17.425 0.39 V RR1 155 17:37:43.09 -03:14:04.5 m1 ---- 14.663 0.06 V SR? Note 156 17:37:43.60 -03:14:24.6 u ---- -- -- CST? Note 157 17:37:43.97 -03:16:12.2 m1 0.2626 17.401 0.50 V RR1 158 17:37:44.01 -03:13:00.2 m1 0.7221 17.318 0.21 V RR0 159 17:37:44.16 -03:13:43.8 m1 0.2896 17.367 0.46 V RR1 160 17:37:44.42 -03:15:33.6 m1 0.3402 17.106 0.50 V RR1 161 17:37:44.52 -03:11:51.5 f ---- -- -- CST? Note 162 17:37:49.78 -03:11:48.1 m1 ---- 14.6 -- V SR 163 17:37:53.87 -03:14:16.6 m1 0.2903 17.238 0.48 V RR1 164 17:37:56.24 -03:10:15.5 m1 0.3326 17.189 0.43 V RR1 165 17:37:36.95 -03:14:53.1 m1 ---- 15.0 V SR? 166 17:37:36.60 -03:14:17.9 m1 0.6715 16.892 0.46 V RR0 167 17:37:33.48 -03:15:27.9 m1 6.2010 15.558 0.20 V CW 168 17:37:26.13 -03:09:45.5 f 1.2687 16.775 -- V EW f;Note 169 17:37:35.36 -03:15:22.9 f 0.3489 17.045 0.37 V RR1 Note 170 17:37:41.43 -03:16:03.2 m1 22.7762 14.312 0.131 V SR Note 171 17:37:39.85 -03:15:06.7 m1 ---- 14.5 -- V SR 172 17:37:33.95 -03:15:11.8 m1 0.7205 17.445 0.68 V RR0 Note 173 17:37:42.14 -03:15:29.2 m1 0.2532 17.252 0.209 V RR1 174 17:37:23.24 -03:14:51.9 m1 0.2622 17.319 0.193 V RR1 +nonrad 175 17:37:40.82 -03:14:22.1 m1 0.2991 17.491 0.660 V RR1 176 17:37:47.85 -03:16:36.6 m1 11.21 {14.688} V SR 177 17:37:37.91 -03:16:47.9 m1 0.0690 18.841 0.260 V SX 178 17:37:41.88 -03:11:56.9 m1 18.05 15.246 -- V SR 179 17:37:30.49 -03:15:53.1 m1 14.757 -- V SR 180 17:37:33.25 -03:15:38.4 m1 15.76 14.802 -- V SR 181 17:37:40.94 -03:15:32.9 m1 18.42 14.676 -- V SR 182 17:37:36.98 -03:15:31.9 m3 85.26 14.910 -- V SR 183 17:37:37.42 -03:15:24.2 m1 14.237 -- V SR 184 17:37:38.77 -03:15:18.3 m1 123.07 14.142 -- V SR 185 17:37:35.98 -03:15:15.0 m1 19.09 14.359 -- V SR 186 17:37:34.97 -03:15:04.1 m1 57.92 14.821 -- V SR 187 17:37:33.51 -03:14:39.7 m1 17.61 14.777 -- V SR 188 17:37:38.38 -03:14:37.4 m1 18.07 14.823 -- V SR 189 17:37:28.99 -03:14:37.0 m1 22.54 14.483 -- V SR 190 17:37:34.98 -03:14:34.9 m1 64.05 14.742 -- V SR 191 17:37:43.79 -03:14:23.4 m1 17.23 14.339 -- V SR 192 17:37:32.65 -03:14:12.9 m1 16.69 14.470 -- V SR 193 17:37:37.96 -03:14:12.1 f 33.32 15.065 -- V SR 194 17:37:38.64 -03:13:44.7 m1 32.46 14.765 -- V SR Nova 17:37:38.3 -03:14:42 u ---- 16.0 -- B Nova? Note PSR -- -- -- -- -- -- u ---- -- -- 5 msPs ========================================================================= Supplementary Notes M14 is a moderately metal rich cluster, with [Fe/H] = -1.28 according to Harris (2010). Investigations by Contreras Pena et al. (2013, 2018 - hereafter CP13, CP18) have shown that it is one of the 10 brightest Galactic globular clusters. It has a fairly high reddening, E(B-V) ~ 0.6, with differential reddening across the face of the cluster, at the level of Delta E(B-V) = 0.17 mag. For this reason, it is challenging to observe. The first study of the variable stars in M14 was carried out by Helen Sawyer Hogg (Sawyer 1938) based on photographs she obtained at the DAO in Victoria, B.C. and the DDO in Richmond Hill, Ontario. She discovered 72 variables. However, she noted that the cluster was a difficult object because of its large congested area. Consequently, she estimated that it would take several years to determine the periods of a large percentage of the variables. Several years turned out to be more than 25 years. Although she initially derived periods for three type II Cepheids, the analysis of the remaining variables was not completed until the 1960s when she began a collaboration with Amelia Wehlau. Amelia Wehlau continued to work on the M14 variables throughout the next three decades. In 1994, she published a paper (Wehlau & Froelich 1994 - hereafter WF94) that summarized the properties of variables, V1-93. They published an ID chart that included all of the variables except V28 which was outside the field of their chart. Their paper also included an appendix with notes on many of the individual stars, including all of the catalogued variables that they were unable to classify. Comprehensive CCD studies of the variable stars in M14 were subsequently carried out by Conroy et al. (2012 - hereafter Con12), CP18 and Yepez et al. (2022 - hereafter Yep22). In the above table, the data for V1-172 are from CP18 and V173-194 are from Yep22 unless indicated otherwise in the notes on individual stars. However, for stars designated as CST, CP18 and Yep22 did not publish RA and dec. Therefore, for CST stars numbered between V1 and V93, the RA and dec are from Samus et al. (2009) These "CST stars" were observed by both Con12 and by CP18 and neither group detected any variability. Furthermore, WF94 noted that it was hard to confirm variability or derive periods for these stars because many of them had blended images. For "CST? stars numbered higher than V93, the RA and dec are from Con12. These variables were all announced by Con12, but not confirmed by CP18 and not discussed by Yep22. Membership status: In their investigation, Yep22 used GAIA-EDR3 astrometric data to establish membership status for the M14 variables. The stars designated "f" in the Remarks column are stars that they classified as field stars. The remaining stars are probably members, based on astrometric data or location in the CM diagram. For further details, please consult their paper. =================================================== Notes on individual stars V1, V51: The ID charts published by WF94 have 2 stars labelled as V1. The star at position x=+104", y=-305" in Fig. 1a should be V51. V1 is located at x=+17", y=+47" in Fig. 1b. This error was pointed out by Samus et al. (2009). V3: The light curves published by Con12, CP18 and Yep22 all show very pronounced long term modulations in amplitude, i.e. the Blazhko effect. V23: The coordinates that Con12 listed for V23 refer to a star that is about 6 arcminutes north of the original V23 that was discovered by Sawyer (1938). Con12's V149 is the original V23 and their V23 was later announced as V170 by CP18. V25: Con12 did not detect variations in this star, probably because it was at the edge of their field. The light curve published by Sawyer Hogg & Wehlau (1966) indicates that V25 must certainly be variable and CP18 confirmed this. It was outside of the field of the Yep22 investigation. V27: This star was outside the field of view in the studies of Con12, CP18, and Yep22. However, it is considered to be a cluster member. Yep22 established this using Gaia-EDR3 proper motion data. Also, with a distance of about 7.5 arcminutes from the cluster centre, it is inside the tidal radius which is 7.7 arcminutes according to Harris (2010). The AAVSO Photometric All-Sky Survey (Henden et al. 2015) lists V=14.519 and (B-V)= 2.216 mag, near the RG tip in the CM diagram. V27 is classified as SR with a period of approximately 305 days. WF94 listed a period of 308 days, the Moscow GCVS (where V27 is V4119 Oph) lists 305.8 days and the ASAS-SN catalogue of variables (Jayasinghe et al. 2020) lists 302.3 days. All of the data listed for V27 in the above table are from the ASAS-SN catalogue. V28=V4118 Oph: All of the data listed in the above table are from the Moscow GCVS. The binary classification for this star was previously indicated by Sawyer Hogg (1973) and by WF94 who noted that it is located almost 10 arcminutes from the cluster centre, which is well outside the tidal radius (7.7 arcminutes). It was outside the field observed by Con12, CP18 and by Yep22. Yep22 confirmed its field star status from Gaia-EDR3 proper motion data. V35 and V71: These two stars are separated by about 4 arcsec. WF94 derived a period (0.5259) for V71, but could not derive a period for V35. On the other hand Con12 derived a period (0.5266) for V35 and did not detect variability in V71. An examination of the RA and dec values that Samus listed for these stars indicates that the star Con12 listed as V35 is V71 and that V35 is not variable. V43, V86, V151: V43 and V86 are separated by approximately 2.5 arcsec on the photographic chart published by WF94. These authors pointed out that there had been some previous confusion between V43 and V86 because they listed the wrong coordinates for V86 in their discovery paper (Wehlau & Potts 1972). Their V86 coordinates indicated a position southwest of V43 when it should have been northeast. There is also some confusion between V86 and V151. Con12 announced a new variable V151 with position approximately 4 arcsec northeast of 43. Thus, it appears that their V151 might actually be the star Wehlau & Potts meant to announce as V86. However, to avoid confusion, Con12's number is adopted in the above table and V86 is considered to be non-variable. V151 was later recovered by CP18 who confirmed that V86 was not variable. The Yep22 data for V43 and V151 agree with the CP18 values. V45: Con12 did not confirm the variability of this red variable. However, its variability was detected by CP18 and Yep22. V45 is located near the RG tip in the CM diagram. V50, V169: CP18 pointed out that V169 lies 2.2 arcseconds northeast from the position of V50 on the ID chart published by WF94 but could not confirm that V169 and V50 are the same star. Therefore they assigned the new number, V169. V50 is considered to be non-variable. V94, V108, V113, V115: Con12 derived RR Lyrae periods for these variables. However, none of them were detected as variables by CP18. In addition, none were listed among the stars that CP13 observed for their CM diagram. Therefore their variability status is uncertain. None of them were discussed by Yep22 in their investigation. The RA and dec for these stars are from Con12. V101, V103, V125, V146, V156: These variables were detected by Con12 who concluded that they all had periods of 15 days or greater. None of them were detected as variables by CP18. In addition, none were listed among the stars that CP13 observed for their CM diagram. Also none of them were discussed by Yep22 in their investigation. Therefore their variability status is uncertain. The RA and dec for these stars are from Con12. V124: In their table, Con12 list a period of 0.2762 days for V124. However, on their light curve, they list P=0.5702 days which is closer to the periods derived by CP18, P=0.5699 days, and by Yep22, P= 0.5700 days. V155: This variable was announced by Con12 who concluded that it varied with a period of approximately 15 days. Its variability was not detected by CP18. However, CP13 showed that the star was located near the RG tip on the CM diagram. Yep22 detected mild variations and derived a tentative period of 36.545 days. They concluded that it was probably an SR variable based on its CM diagram location, but further data were needed to confirm this. The data listed in the above table are from Yep22. V161: Con12 classified this as an SX Phe variable and derived a period 0.0490 days. However, it was not detected as a variable by CP18. Furthermore, it was not listed among the stars that CP13 observed for their CM diagram and it was not discussed by Yep22 in their investigation. Therefore its variability status is uncertain. The RA and dec are from Con12. V168: The period (1.26866 days) is from Merchak & Murphy (2020) based on two years of observations. The remaining data are from CP18 who derived P=1.27 days. V170: This variable, announced by CP18, is the star that Con12 erroneously listed as V23. It is located approximately 6 arcminutes north of V23. Con12 showed that it probably has a period greater than 25 days and CP18 showed that it lies near the RG tip on the CM diagram, indicating that it is an SR variable. The period (22.7 days), V magnitude and amplitude in the above table are from Yep22. V172: This variable, announced by CP18, has coordinates close to Con12's V111. Since the periods derived for the two stars are different (P=0.28 for V111 and P=0.72 for V172), CP18 concluded that they were different stars and that the low amplitude variability of V111 made it difficult to detect. However, a close examination of the light curve Con12 published for V111 indicates that their period is incorrect. Furthermore, in view of the systematic shift in the RA values derived in the two studies, it is highly probable that V111 and V172 are the same star. AF confirmed the CP18 period, but derived a fainter V magnitude (17.715) and larger amplitude (0.905 mag) suggestng that there was an unresolved companion in the CP18 images. Nova: The maximum B magnitude for the suspected nova is from the discovery paper by Sawyer Hogg & Wehlau (1964a,b). At the time of its discovery, the star was considered to be a probable nova. Although the suspected nova was announced in 1964, it was discovered on eight plates obtained at the David Dunlap Observatory in June 1938. They were the only plates of M14 taken that year and it did not appear on any other plates of M14 which were obtained on 124 different nights in 23 of the years from 1932 to 1963 inclusive. Some years later, Shara et al. (1986) imaged the field with a CCD camera at the prime focus of the CTIO 4-metre telescope and identified a candidate for the nova. However, they noted that confirmation would probably require Hubble Space Telescope observations. The RA and dec listed in the above table are from their investigation. In a subsequent attempt to recover the nova in its quiescent phase using the HST, Margon et al. (1991) found that the candidate was resolved into at least six separate images, none of which was considered to be an outstanding candidate. This led Shara & Drissen (1995) to suggest that the star might have been a background supernova. Finally, Shara et al. (2004) commented that the Nova candidate in M14 was a "genuine variable that had the right brightness to be a classic nova, but details of its light curve are far too scant to determine its true nature. Consequently its classification is uncertain. ============================================= Discovery of the Variable Stars in M14: V1-72 Sawyer (1938) with x,y positions and an ID chart (but V27 & 28 were outside the field of the chart). V73-76 Sawyer Hogg & Wehlau (1966) with x,y positions and an ID chart V77-88 Wehlau & Potts (1972) with x,y positions V89-93 Wehlau et al. (1974) with x,y positions V94-164 Con12 with RA and dec They applied the image subtraction technique to CCD images obtained with telescopes at Kitt Peak and Cerro Tololo. They confirmed the variability of 61 of the variables discussed by WF94 and identified 71 new ones (V94-164). V165-172 CP18 with RA and dec (J2000) and a finding chart V173-194 Yep22 with RA and dec (J2000) and identification charts Nova Sawyer Hogg & Wehlau (1964a,b) with x,y position and with an ID chart in 1964b. PSR: According to Paulo Freire's website at the Max Planck Institute in Bonn (July 2024 version), there are 5 millisecond pulsars in NGC 6402 (M14). ================================================================== ------------------------------------------------------ Weinschenk et al. (2018) carried out a study of the variable stars in M14 and presented a summary at AAS Meeting #231, id. 146.17 =================================================================== References Conroy, K. E., Darragh, A. 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