NGC 7089 / C2130-010 / Messier 2 (Updated July 2017) RA: 21:33:27.02 DEC: -00:49:23.7 (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 21:33:28.46 -00:47:55.4 R0 15.5647 13.36 1.1 V CW Note 2 21:33:23.70 -00:48:04.5 R0 0.5278 16.031 1.210 V RR0 Note 3 21:33:41.62 -00:49:53.1 R0 0.6197 15.963 1.062 V RR0 4 21:33:24.72 -00:48:45.0 R0 0.5642 15.929 1.025 V RR0 5 21:33:23.84 -00:49:12.9 R0 17.557 13.28 0.85 V CW Note 6 21:33:27.52 -00:49:59.6 R0 19.299 13.14 1.0 V CW Note 7 21:33:36.97 -00:52:22.6 R0 0.5949 15.962 1.042 V RR0 8 21:33:22.30 -00:50:11.5 R0 0.6437 15.946 0.981 V RR0 9 21:33:15.24 -00:51:23.7 R0 0.6093 16.001 1.038 V RR0 10 21:33:32.73 -00:48:35.0 R0 0.8757 15.733 0.634 V RR0 11 21:33:32.41 -00:49:05.8 R0 67.0 12.11 1.1 V RV Note 12 21:33:22.64 -00:48:32.9 R0 0.6656 15.909 1.007 V RR0 13 21:33:21.54 -00:48:03.1 R0 0.7066 15.921 0.839 V RR0 14 21:33:32.36 -00:50:20.9 R0 0.6938 15.969 0.759 V RR0 15 21:33:32.21 -00:50:29.5 R0 0.3008 16.077 0.456 V RR1 16 21:33:24.81 -00:49:42.1 R0 0.6559 16.013 1.012 V RR0 Note 17 21:33:26.99 -00:50:17.6 R0 0.6364 15.863 1.202 V RR0 18 21:33:14.03 -01:01:05.3 R0 0.3621 15.951 0.624 V RR1 19 21:33:42.81 -00:57:43.7 R0 0.3194 16.048 0.558 V RR1 20 21:33:53.09 -00:47:56.8 R0 0.2863 16.065 0.376 V RR1 21 21:33:48.95 -00:45:45.4 R0 0.7122 15.970 0.831 V RR0 22 21:33:26.90 -00:48:32.7 R0 0.7020 15.749 1.004 V RR0 23 21:33:32.48 -00:50:03.4 R0 0.7812 15.908 0.537 V RR0 24 21:33:27.73 -00:51:04.9 R0 0.3582 15.992 0.457 V RR1 25 21:33:26.87 -00:49:55.9 R0 0.7287 16.075 0.877 V RR0 26 21:33:31.56 -00:49:22.6 R0 0.4124 15.922 0.482 V RR1 Note 27 21:33:23.23 -00:47:14.1 R0 0.3142 15.947 0.121 V RR1 28 21:33:27.36 -00:47:36.1 R0 0.8238 15.942 0.183 V RR0 29 21:33:22.46 -00:50:51.7 R0 0.3058 16.020 0.182 V RR1 30 21:33:32.91 -00:48:31.3 R0 0.2729 16.118 0.223 V RR1 31 21:33:30.23 -00:49:18.5 R0 0.7887 16.066 0.553 V RR0 32 21:33:30.08 -00:49:57.7 R0 0.3670 16.038 0.612 V RR1 Note 33 21:33:23.42 -00:49:34.5 R0 0.3080 15.931 0.515 V RR1 34 21:33:31.30 -00:49:56.5 R0 0.3914 15.975 0.523 V RR1 35 21:33:28.00 -00:47:31 R0 0.3256 -- -- RR1 36 21:33:30.71 -00:49:13.5 R0 0.2708 -- -- RR1 37 21:33:26.04 -00:49:18.1 R0 0.5667 -- -- RR0 38 21:33:31.20 -00:49:23.8 R0 0.8073 -- -- RR0 39 21:33:27.38 -00:50:07.2 R0 0.6078 -- -- RR0 40 21:33:25.66 -00:49:16.3 R0 0.7517 -- -- RR0 41 21:33:28.02 -00:49:24.3 R0 0.6053 -- -- RR0 42 21:33:28.42 -00:49:54.6 R0 0.3280 -- -- RR1 43 21:33:26.44 -00:49:29.3 R0 ---- -- -- RR 44 21:33:26.69 -00:49:21.8 R0 ---- -- -- RR 45 21:33:26.13 -00:49:22.2 R0 ---- -- -- RR 46 21:33:27.45 -00:49:15.5 R0 ---- -- -- RR 47 21:33:27.40 -00:49:05.4 R0 ---- -- -- RR 48 21:33:27.51 -00:49:07.5 R0 ---- -- -- RR 49 21:33:30.45 -00:50:29.6 R0 ---- -- -- RR? f?;Note 50 21:33:26.63 -00:49:11.2 R0 ---- -- -- RR 51 21:33:24.94 -00:48:43.3 R0 ---- -- -- RR 52 21:33:25.1 -00:49:24.4 R0 ---- -- -- RR 53 21:33:28.24 -00:49:35.4 R0 ---- -- -- RR 54 21:33:27.55 -00:49:29.1 R0 ---- -- -- RR 55 21:33:26.37 -00:49:18.1 R0 ---- -- -- RR 56 21:33:31.6 -00:50:13.0 R0 0.0468 18.11 0.10 i SXPHE 57 21:33:27.54 -00:49:21.4 R0 0.0686 -- -- SXPHE blended ================================================================== Supplementary Notes For V1-34: The RA and dec are from Samus et al. (2009) Periods, magnitudes, amplitudes and variability types are from Lee & Carney (1999) unless indicated otherwise in the notes on individual stars. For V35-42: Most of the data are from the discovery paper by Lazaro et al. (2006). No magnitudes were derived because they used the image subtraction technique. For V36-42, revised RA and dec published by Salinas et al. (2016) have been listed. They also published tentative mean "i" magnitudes and amplitudes. However, these have not been listed here because they were considered to be uncertain. For V43-57: All the data are from Salinas et al. (2016) who did not have enough observations to derive periods. They also published tentative mean "i" magnitudes and amplitudes. However, most of these values have not been listed here because they were considered to be uncertain. =============================== Notes on individual stars V1, V5, V6, V11: Periods, magnitudes, amplitudes and variability types are from Demers (1969) who published an ID chart. For V11, he listed the half period (33.5 days), but noted that the star is probably an RV Tauri variable. V2, V26, V32: Periods are from Lazaro et al. (2006) and magnitudes, amplitudes and variability types are from Lee & Carney (1999) V16: Lazaro et al. (2006) did not detect any star at the previously reported position for V16 and did not detect variablity in nearby stars. However, Lee & Carney (1999) derived a V amplitude of more than 1 mag for the star and confirmed the period that Sawyer (1935) derived in her discovery paper. V49: If this star is an RR Lyrae variable, it is a background variable and not a cluster member. Salinas et al. (2016) noted that it might also be a contact binary of the W U Ma type, but a hump before maximum light on its light curve makes that interpretation less likely. ================================================================= Discovery of the variable stars in M2: V1-10 Bailey (1902) with x,y positions (p 244) and ID chart (Plate XII, Fig. 3) V11 announced by Chevremont (1897) with ID chart (1898) This star was designated V11 by Sawyer (1935) V12-17 Sawyer (1935) with ID chart for V1-17 and x,y positions for V11-17 listed by Sawyer (1938) V18-21 Margoni & Stagni (1967) with x,y positions and (1969) with ID chart V22-34 Lee & Carney (1999) with ID chart V22-34 = LC 184, 301, 450, 456, 608, 651, 708, 715, 733, 798, 864, 939, 1047 respectively The numbers V22-34 were assigned in our electronic catalogue (Clement et al. 2001). V35-42 Lazaro et al. (2006) with RA, dec and ID chart V43-57 Salinas et al (2016) with RA and dec (J2000) -------------------------------------------------------------------- Kraemer et al. (2014) announced that they are making near-infrared observations in order to identify long period variables in M2. ---------------------------------------------------------------- Lynch & Ransom (2011) conducted a search for pulsars, but did not find any in M2. ============================================================================ References Bailey, S. I. 1902, Harv. Ann., 38 Chevremont, A. 1897, Bul. Soc. Astr. France Vol. 11, 485 Chevremont, A. 1898, Bul. Soc. Astr. France Vol. 12, 90 Clement, C. M., Muzzin, A., Dufton, Q., Ponnampalam, T., Wang, J., Burford, J., Richardson, A., Rosebery, T. 2001, AJ, 122, 2587 Demers, S. 1969, AJ, 74, 925 Kraemer, K. E., Sloan, G. C., Clemens, D. P., Lagadec, E., Barry, D. J., Goes, C W. 2014, AAS Meeting #224, #223.11 Lazaro, C., Arellano Ferro, A., Arevalo, M. J., Bramich, D. M., Giridhar, S., Poretti, E. 2006, MNRAS, 372, 69 Lee, J.-W. & Carney, B. W. 1999, AJ, 117, 2868 Lynch, R. S. & Ransom, S. M. 2011, ApJ, 730, L11 Margoni, R. & Stagni, R. 1967, IBVS 239 Margoni, R. & Stagni, R. 1969, Mem. SAI., 40, 143 Salinas, R., Contreras Ramos, R., Strader, J., Hakala, P., Catelan, M., Peacock, M. B., Simunovic, M. 2016, AJ, 152, 55 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Sawyer, H. B. 1935, Pub D.A.O., 6, No. 14 Sawyer, H. B. 1938, Pub D.A.O. 7, No. 5 ======================================================================