The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster NGC 3201
Kaluzny, J.; Thompson, I. B.; Narloch, W.; Pych, W.; Rozyczka, M.
Abstract:
The field of the globular cluster M12 (NGC 6218) was monitored between 1995 and 2009 in a search for variable stars. BV light curves were obtained for thirty-six periodic or likely periodic variable stars. Thirty-four of these are new detections. Among the latter we identified twenty proper-motion members of the cluster: six detached or semi-detached eclipsing binaries, five contact binaries, five SX Phe pulsators, and three yellow stragglers. Two of the eclipsing binaries are located in the turnoff region, one on the lower main sequence and the remaining three among the blue stragglers. Two contact systems are blue stragglers, and the remaining three reside in the turnoff region. In the blue straggler region a total of 103 objects were found, of which 42 are proper motion members of M12, and another four are field stars. 55 of the remaining objects are located within two core radii from the center of the cluster, and as such they are likely genuine blue stragglers. We also report the discoveries of a radial color gradient of M12, and the shortest period among contact systems in globular clusters in general.

DOWNLOADS:
The paper (PDF) "The Clusters AgeS Experiment (CASE). Variable Stars in the Field of the Globular Cluster NGC 3201"
Kaluzny, J.; Thompson, I. B.; Narloch, W.; Pych, W.; Rozyczka, M.;
2015, Acta Astronomica, vol 65, no 3, p. 267-282
The reference
V-band image (FITS)


Table 1: Basic properties of variable stars in NGC3201 identified within the present survey*
Star RA [2000] Decl. [2000] Period [days] Vmax B-V ΔV PMa Typeb V light-curvec B light-curvec Remarks
V119 10:17:45 -46:25:13 2.551572 16.049 0.582 0.202 U EA,BS V119.ph -
V125 10:18:07 -46:21:50 0.042236 17.449 0.512 0.045 Y SX,BS V125.ph -
V126 10:17:44 -46:20:58 0.039888 17.405 0.473 0.052 Y SX,BS V126.ph -
V127 10:17:41 -46:24:33 0.045335 17.184 0.440 0.064 Y SX,BS V127.ph -
V128 10:17:37 -46:23:55 0.034489 17.410 0.495 0.052 Y SX,BS V128.ph -
V129 10:17:36 -46:23:01 0.051988 17.172 -- 0.051 Y SX V129.ph -
V130 10:17:41 -46:25:18 0.047317 16.357 0.477 0.021 Y SX,BS V130.ph -
V131 10:17:15 -46:23:12 0.033090 17.244 0.462 0.041 Y SX,BS V131.ph -
V132 10:17:04 -46:19:55 0.047643 16.551 0.430 0.103 Y SX,BS V132.ph -
V133 10:17:45 -46:22:60 0.270517 18.305 0.645 0.369 Y EW V133.ph -
V134 10:17:44 -46:24:04 0.285316 17.520 0.519 0.094 Y EW,BS V134.ph -
V135 10:17:39 -46:24:30 0.279262 17.916 0.788 0.130 Y EW V135.ph -
V136 10:17:25 -46:24:44 0.702218 16.197 0.352 0.033 Y EW,BS V136.ph -
V137 10:17:43 -46:22:13 7.429154$^1$ 17.911 0.653 0.087 Y EA V137.ph -
V138 10:17:28 -46:23:26 9.199380 18.292 0.720 0.124 Y EA V138.ph -
V139 10:17:23 -46:23:58 8.789090 18.076 0.716 0.297 Y EA V139.ph -
V140 10:17:15 -46:24:46 -- 18.499 0.801 0.411 Y EA V140.ph -
V141 10:17:33 -46:25:07 10.00370 17.154 0.779 0.149 Y EA V141.ph -
V142 10:17:10 -46:22:38 27.69300 17.257 0.756 0.108 Y EA V142.ph -
V143 10:17:10 -46:28:04 0.380726 20.565 1.049 0.324 Y EA V143.ph -
V144 10:18:14 -46:19:42 0.938225$^2$ 14.626 1.066 0.025 Y EB? V144.ph -
V145 10:17:48 -46:29:05 24.34624 18.133 0.679 0.110 Y ? V145.ph -
V146 10:17:30 -46:24:42 13.75904$^1$ 17.275 0.932 0.158 Y SP,RG V146.ph -
V147 10:17:21 -46:26:21 1.910503$^3$ 17.410 0.757 0.124 Y SP? V147.ph -
V148 10:18:10 -46:18:53 0.467678$^4$ 17.235 0.889 0.040 Y ? V148.ph -
V149 10:18:02 -46:21:56 0.062268 21.280 0.701 0.485 Y EB? V149.ph -
V150 10:18:03 -46:23:39 0.18642$^2$ 15.225 0.322 0.016 Y ? V150.ph -
V151 10:17:38 -46:19:49 1.033544$^3$ 14.275 1.043 0.021 Y ? V151.ph -
V152 10:17:35 -46:19:38 0.516789 14.692 0.756 0.018 Y ? V152.ph -
V153 10:17:40 -46:21:55 0.899928$^3$ 17.592 0.484 0.089 Y ? V153.ph -
V154 10:17:27 -46:23:48 0.168045$^4$ 16.498 0.321 0.024 Y ? V154.ph -
V155 10:17:25 -46:25:19 0.252956 17.690 0.670 0.056 Y EW? V155.ph -
V156 10:17:35 -46:26:30 0.041316 17.084 0.840 0.029 Y SX? V156.ph -
V157 10:17:33 -46:26:45 0.174603 15.651 0.916 0.016 Y EW? V157.ph -
V158 10:17:22 -46:26:44 0.199170 19.501 0.805 0.162 Y EW? V158.ph -
V159 10:17:10 -46:23:09 0.387159 17.392 0.894 0.028 Y EW? V159.ph -
V160 10:17:47 -46:28:50 2100.000$^5$ 17.695 0.611 0.170 Y LPV V160.ph -
VN1 10:17:40 -46:23:25 0.398926 17.682 0.856 0.113 N EW VN001.ph -
VN2 10:17:36 -46:25:12 0.297544 17.702 0.533 0.359 N EW,BS? VN002.ph -
VN3 10:17:44 -46:28:28 0.336212 19.660 0.924 0.384 U EW VN003.ph -
VN4 10:17:37 -46:26:24 0.398336 21.713 -- 0.905 U EW VN004.ph -
VN5 10:17:06 -46:20:37 0.286946 17.197 0.785 0.154 N EW VN005.ph -
VN6 10:18:12 -46:18:44 1.063468 18.576 0.868 0.104 N EA VN006.ph -
VN7 10:18:08 -46:27:24 0.967542 20.570 1.430 0.464 N EA VN007.ph -
VN8 10:17:43 -46:22:14 2.860388 20.641 0.602 0.693 U EA VN008.ph -
VN9 10:17:48 -46:26:44 8.909326 16.441 0.759 0.087 N EA VN009.ph -
VN10 10:17:05 -46:34:00 -- 17.641 0.924 0.326 N EA VN010.ph -
VN11 10:17:46 -46:27:21 4.341275 17.521 0.581 0.111 N SP VN011.ph -
VN12 10:17:58 -46:28:46 23.84405 14.355 0.922 0.026 N SP VN012.ph -
VN13 10:18:02 -46:15:41 0.377768 15.780 0.846 0.019 N EW? VN013.ph -
VN14 10:17:59 -46:13:01 0.088603 19.967 1.502 0.389 U EW? VN014.ph -
VN15 10:17:51 -46:17:22 15.95484 17.623 1.255 0.140 N SP? VN015.ph -
VN16 10:18:15 -46:21:44 1.123061 16.075 0.884 0.030 N SP? VN016.ph -
VN17 10:18:14 -46:22:52 0.493302 15.375 0.886 0.022 N ? VN017.ph -
VN18 10:18:07 -46:20:55 7.862955 16.566 1.233 0.035 N SP? VN018.ph -
VN19 10:18:14 -46:27:31 0.092057 14.668 0.635 0.030 N ? VN019.ph -
VN20 10:18:23 -46:28:59 0.166173 14.653 0.596 0.016 U ? VN020.ph -
VN21 10:17:13 -46:22:21 7.299531 18.590 1.179 0.084 N SP? VN021.ph -
* We follow the naming convention of von Braun et al. (2002), who are the discoverers of the first two variables listed in the table.
Their variable V1 is not the W Vir pulsator referred to as V1 by Clement et al. (1988).
a Proper motion membership status — Y - member, N - field star, U - uncertain
b Variable type

EW - contact binary; EB - close ecppsing binary; EA - detached ecppsing binary;

SX - SX-Phenicis type pulsator; Sp - spotted variable; LP - long period;

BS - blue straggler; Ell - ellipsoidal variable; RG - red giant.

c Data columns:
  1. HJD - 2 450 000.0
  2. V magnitude
  3. error of magnitude (dummy points are maked with the error=9.999)
  4. phase