NGC 6864 / C2003-220 / Messier 75 (Updated August 2014) RA: 20:06:04.69 DEC: -21:55:16.2 (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 20:06:06.0 -21:56:43 R0 0.5901 -- -- RR0 2 20:06:03.95 -21:54:14.1 R0 ---- 17.1 0.4 B SR PRC 3 20:06:06.25 -21:53:51.0 R0 0.5451 17.810 0.73 V RR0 4 20:06:03.68 -21:56:45.1 R0 0.2847 17.683 0.57 V RR1 5 20:06:12.62 -21:54:43.0 R0 ---- -- -- CST 6 20:06:05.40 -21:56:40.9 R0 ---- -- -- CST 7 20:06:02.84 -21:54:00.0 R0 ---- -- -- CST 8 20:06:03.95 -21:55:59.3 R0 0.8398 17.432 0.60 V RR0 Note 9 20:06:08.1 -21:55:44 R0 0.3492 17.729 0.63 V RR1 10 20:06:01.7 -21:54:27 R0 ---- -- -- CST 11 20:05:56.13 -21:53:53.4 R0 0.2563 17.851 0.41 V RR1 12 20:06:07.54 -21:54:02.0 R0 0.2706 17.848 0.54 V RR1 13 20:06:14.23 -21:56:18.2 R0 0.4924 17.756 1.30 V RR0 14 20:06:07.66 -21:55:22.2 R0 0.5758 -- -- RR0 15 20:06:00.29 -21:55:16.8 R0 ---- -- -- CST 16 20:06:02.73 -21:54:21.1 R0 ---- 16.9 0.6 B SR PRC 17 20:06:00.14 -21:55:12.7 R0 ---- 16.95 0.5 B SR PRC 18 20:06:04.25 -21:54:21.8 R0 0.5656 -- -- RR0 19 20:06:04.98 -21:54:38.8 R0 0.5677 17.633 1.14 V RR0 20 20:06:04.40 -21:54:53.4 R0 0.5136 17.571 1.34 V RR0 21 20:06:02.96 -21:55:09.8 R0 0.2566 -- -- RR1 22 20:06:05.65 -21:55:35.9 R0 0.5144 -- -- RR0 23 20:06:06.06 -21:55:38.9 R0 0.6122 17.742 0.73 V RR0 24 20:06:03.68 -21:55:41.8 R0 0.5349 17.665 0.86 V RR0 25 20:06:05.32 -21:55:44.4 R0 0.3776 16.964 0.30 V RR1 26 20:06:06.90 -21:55:54.8 R0 0.5421 -- -- RR0 27 20:06:02.82 -21:56:10.8 R0 0.6503 17.797 0.54 V RR0 Note 28 20:06:02.46 -21:55:59.8 R0 0.2930 -- -- RR1 29 20:06:08.33 -21:55:00.5 R0 0.3536 17.752 0.50 V RR1 30 20:06:06.34 -21:55:05.4 R0 0.6834 -- -- V RR0 31 20:06:06.04 -21:55:15.1 R0 0.2662 -- -- RR1 32 20:06:05.38 -21:55:22.5 R0 0.6262 -- -- RR0 33 20:06:04.97 -21:55:25.0 R0 0.5651 -- -- RR0 34 20:06:04.18 -21:55:45.8 R0 0.4724 -- -- RR0 35 20:06:04.15 -21:55:13.9 R0 0.5673 -- -- RR0 36 20:06:04.03 -21:55:22.3 R0 0.3739 -- -- RR1 37 20:06:03.71 -21:55:18.9 R0 0.5969 -- -- RR0 38 20:06:03.69 -21:55:21.5 R0 0.5304 -- -- RR0 39 20:06:04.89 -21:55:12.3 R0 0.6273 -- -- RR0 40 20:06:04.64 -21:55:10.4 R0 0.5511 -- -- RR0 41 20:06:04.58 -21:55:29.7 R0 0.6468 -- -- RR0 42 20:06:04.88 -21:55:31.3 R0 0.5967 -- -- RR0 43 20:06:04.94 -21:55:15.5 R0 0.2960 -- -- RR1 44 20:06:08.04 -21:56:30.8 R0 0.6630 17.809 0.25 V RR0 45 20:06:06.02 -21:55:48.6 R0 0.2511 17.666 0.13 V RR1 46 20:06:04.16 -21:55:12.2 R0 0.3415 -- -- RR1? 47 20:06:04.04 -21:55:23.8 R0 0.5642 -- -- ? 48 20:06:05.36 -21:55:19.9 R0 0.278 -- -- RR1? 49 20:06:05.19 -21:55:15.5 R0 0.276 -- -- RR1? blend? 50 20:06:04.90 -21:55:16.8 R0 0.634 -- -- EB? 51 20:06:04.79 -21:55:16.6 R0 0.269 -- -- RR1? ========================================================================== Supplementary Notes Note that V18-47 are NV1-30 of Corwin et al. (2003) and V48-51 are NV1-4 of Scott et al. (2006). The RA and dec for V1-17 are from Samus et al. (2009). The RA and dec for most of the other stars were supplied by Rodrigo Contreras (2012, private communication) from the investigation by Contreras et al. (2012). The exceptions were V21, V24, V27, V28, V34 and V47-51. For these stars, the RA and dec were calculated from the x,y positions published by Corwin et al. (2003) and Scott et al. (2006). For these calculations, it was assumed that the origin of their x,y system was RA=20:06:04.90 and dec=-21:55:17.8. Making this assumption gave good agreement with the coordinates Contreras et al. derived for the other stars. All of the remaining data for V1-47 are from Corwin et al. (2003) unless indicated by PRC in the remarks column, in which case they are from Pinto et al. (1982). Corwin et al. did not derive magnitudes and amplitudes for all of the variables because they used the image subtraction technique for their analysis. They observed in B and V, but only V magnitudes are listed here. All of the data for V48-51 are from Scott et al. (2006). Contreras et al (2012) identified 62 blue straggler stars which are highly segregated in the cluster core. They published their RA, dec and magnitudes. Some of these are probably variable, but their data were not suitable for carrying out a variable star search. However, the position of their star BSS#5, RA=301.5202849 and dec -21.9213937, seems to be close to the suspected binary V50 (NV4 of Scott et al. 2006). ========================================================================= Notes on individual stars V8,V27: The x,y coordinates (-14, -40) that Corwin et al. listed for their NV10 are very close to the values Shapley (1920) published for V8 (-13.5, -41.4), but Corwin et al. listed (-29, -53) for V8. Thus in the above table, Corwin's NV10 is V8 and the star that Corwin et al. listed as V8 is V27. ===================================================================== Discovery of the variable stars in NGC 6864: V1-12 Shapley (1920) with x,y coordinates and an ID chart He also announced suspected variables V13-16, but Sawyer Hogg did not include these four stars in any of her catalogues. Shapley's V13-16 were referred to as S1-4 by Pinto et al. (1982) and also by Samus et al. (2009) who derived their RA and dec. Pinto et al. noted that they were probably not variable and this result was confirmed by Corwin et al. (2003). V13-17 Pinto et al. (1982) with x,y coordinates and an ID chart V18-47 = Corwin NV1-NV30 Corwin et al (2003) with x,y coordinates V48-51 = Scott NV1-NV4 Scott et al. (2006) with x,y coordinates ============================================================ References Contreras Ramos, R., Ferraro, F. R., Dalessandro, E., Lanzoni, B., Rood, R. T. 2012, ApJ, 748, 91 Corwin, T. M., Catelan, M., Smith, H. A., Borissova, J., Ferraro, F. R., Raburn, W. S. 2003, AJ, 125, 2543 Pinto, G., Rosino, L., Clement, C. M. 1982, AJ, 87, 635 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Scott, N. J., Corwin, T. M., Catelan, M., Smith, H. A. 2006, IBVS, 5706 Shapley, H. 1920, ApJ, 52, 73 =======================================================================