NGC 6752 / C1906-600 RA: 19:10:52.11 DEC: -59:59:04.4 (J2000) (Most recent updates: Membership probability flag - 2024; Remaining data - June 2016) ============================================================ 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 19:11:24.07 -59:56:36.4 m1 1.3782 12.61 0.70 V CW 2 19:10:58.98 -59:57:43.0 m1 ---- -- -- ? 3 19:11:52.44 -59:56:34.0 m1 ---- 11.30 0.16 V L 4 19:09:23.34 -60:07:02.5 f 0.2502 18.49 0.45 V EW max 5 19:09:35.77 -59:49:20.4 u 0.2736 16.89 0.50 V EW max;f 6 19:09:52.70 -59:58:11.1 f 0.3007 19.21 0.37 V EW max;f 7 19:10:54.06 -60:00:12.4 m1 0.0591 15.55 0.45 V SXPHE Note 8 19:11:10.60 -59:58:53.4 m1 0.3149 17.058 0.36 V EA max;Note 9 19:11:26.23 -60:01:24.7 f 0.3636 15.018 0.06 V EW max;f;Note 10 19:11:28.77 -59:48:25.6 f ---- 17.21 0.16 V EA? max;P>2d 11 19:12:16.44 -59:53:07.8 f 0.2783 15.91 0.30 V EW max;f 12 19:10:34.23 -59:56:57.2 m1 0.0409 16.317 0.05 V SXPHE Note 13 19:10:14.44 -60:05:03.4 m1 0.0469 16.26 0.07 V SXPHE 14 19:10:12.75 -60:01:20.9 f 0.3175 18.78 0.13 V EW max 15 19:11:11.33 -59:59:45.3 m1 0.6895 16.344 0.02 V E? max;sdB? 16 19:11:06.43 -59:58:48.2 m1 ---- 16.53 0.04 V ? max;P>8d 17 19:11:04.06 -59:59:07.4 m1 3.2910 15.27 0.02 V E? max;Note 18 19:11:10.00 -60:02:19.0 m1 0.4676 20.74 0.16 V E? max;Note 19 19:11:13.04 -59:55:17.6 f 6.1800 16.38 0.12 V ? altP=1.2 20 19:10:50.50 -59:57:37.2 f ---- 16.090 0.02 V ? max;P>8d 21 19:10:44.94 -60:00:35.9 u 0.5514 16.522 0.09 V GDOR? Note 22 19:10:29.67 -59:56:24.1 f ---- 18.437 0.13 V ? max 23 19:10:32.58 -60:01:33.9 m1 ---- 18.463 0.2 V EA max 24 19:10:29.22 -60:00:56.7 m1 ---- 14.406 0.01 V ? max;P>8d 25 19:10:51.58 -59:59:01.8 m1 ---- 20.328 -- V CV =CX4 26 19:10:51.50 -59:58:56.8 m1 ---- 21.424 -- V CV =CX7;Note 27 19:10:51.13 -59:59:11.8 m1 ---- -- -- CV =CX1 PSR -- -- -- -- -- -- u ---- -- -- 9 msPs ====================================================================== Supplementary Notes NGC 6752 is the subject of many recent studies because of its milli-second pulsars and its X-ray sources. In addition, its multiple stellar populations have been investigated by numerous authors, see e.g., Kravtsov et al. (2014). The cluster is relatively metal poor, with [Fe/H] = -1.54, according to the 2010 update to the Harris (1996) catalogue. Its CM diagram has an extended blue HB. No RR Lyrae variables have been discovered. V1-3: The RA and dec are from Samus et al. (2009). They also pointed out that the y coordinate published for V1 in the previous on-line catalogue (Clement et al. 2001) was incorrect. It should have been +143.0 (not +14.30). The remaining data for V1 are from Lee (1974) and for V3 from the discovery paper by Cannon & Stobie (1973). V4-14: Most of the data are from the discovery paper by Thompson et al. (1999) unless indicated otherwise in the Notes on individual stars. The "f" classification for V5, V6, V9, V11 was by Rucinski (2000) based on photometric criteria. Samus et al. (2009) pointed out that V4, V5, V6, V8 and V11 are V0394, 0395, 0396, 0397 and 0398 Pav respectively. V15-24: All the data are from the discovery paper by Kaluzny & Thompson (2009). V25-27: All the data are from Thomson et al. (2012). ===================================================================== Notes on individual stars V7, V8, V9, V12: The data for these stars are from Kaluzny & Thompson (2009). V8: Classification by Kaluzny et al. (2009) V17: Kaluzny & Thompson (2009) suggested that this star might be a binary composed of a hot EHB star and red companion, based on its location on the CMD. However, Lovisi et al. (2013) concluded that it is probably a BSS in a binary system with a low-mass MS companion, based on its location in the UV plane. V18: Kaluzny & Thompson (2009) showed that this star is located on the faint extension of the EHB and suggested that it may be a degenerate binary hosting a low-mass helium white dwarf. Based on the fact that there was no long term change in the average V luminosity, they concluded that it is not a dwarf nova. V21: Gamma Doradus variables are early F dwarf stars that were first identified as a new class of pulsating stars by Balona et al. (1994). They pulsate in multiple non-radial g modes with periods in the range 0.3 to 3 days. In the CMD, they partly overlap the cool edge of the delta Scuti instability strip. Kaluzny & Thompson (2009) pointed out that, if the Gamma Dor classification for V21 is confirmed, it would be the first variable of this type detected in a globular cluster. V26: Figuera Jaimes et al. (2016) detected an outburst in 2014, but the star was in its quiescent phase when they observed the cluster in 2013. They did not detect any variabiity in the other two CVs (V25 and V27). ====================================================================== Discovery of the variable stars in NGC 6752: V1-2 Fourcade et al. (1966) with x,y coordinates and an ID chart According to Fourcade et al., V1 is considered to be the variable that Sawyer mentioned in her first two catalogues and she acknowledged this in her 3rd edition. The variable was originally announced by Bailey (1902 - in Table 1 on page 2), but no position was published. V3 = star #126 Cannon & Stobie (1973) with ID chart V4-14 Thompson et al. (1999) with ID charts and RA and dec According to Samus et al. (2009), their charts for V4, V6, V11 and V14 are incorrect, but their RA and dec are correct. Proper motions for some of these variables were later obtained by Zloczewski et al. (2012). Their study indicated that V7, V8 and V12 are probable members and that V9 is probably not a member. V15-24 Kaluzny & Thompson (2009) with ID charts and RA and dec Preliminary results for some of these variables were reported in the proceedings of a conference (Kaluzny & Thompson 2008). Proper motions for some of these variables were later obtained by Zloczewski et al. (2012). Their study indicated that V15, V16, V17, V23 and V24 are probable members and that V19, V20 and V22 are probably non-members. V25 = Bailyn CV candidate #1 = CX4 of Pooley et al. (2002) Bailyn et al. (1996) with ID chart and RA and dec Kaluzny & Thompson (2009) confirmed the CV status of this star and assigned the number V25. V26 = Bailyn CV candidate #2 = CX7 of Pooley et al. (2002) Bailyn et al. (1996) with ID chart and RA and dec Thomson et al. (2012) confirmed the CV status of this star and the number V26 has been assigned in this electronic catalogue. V27 = optical counterpart of CX1 of Pooley et al. (2002) Thomson et al. (2012) with ID charts and RA and dec Pooley et al. (2002) listed this source as a possible CV and Thomson et al. confirmed its CV status. Thomson et al. also discovered an SX Phe variable (their star #7581), but it appears too faint to be a cluster member. PSR: According to Paulo Freire's website at the Max Planck Institute in Bonn (July 2024 version), there are 9 millisecond pulsars in NGC 6752. --------------- Dupree & Hartmann (1990) and Dupree et al. (1990) demonstrated spectroscopically that two stars near the red giant tip, #31 and #59 of Alcaino (1972), might be pulsating. Neither of these stars was measured in the Cannon & Stobie (1973) study in which V3 was discovered. --------------- Pooley et al. (2002) detected 19 Chandra X-ray sources in NGC 6752 and made 12 optical identifications. They concluded that 10 of them might be cataclysmic variables. Subsequent studies by Kaluzny & Thompson (2009) and by Thomson et al. (2012) have confirmed that three of their sources CX4, CX7 and CX1 are CVs. They have been assigned the numbers V25, V26 and V27. Kaluzny & Thompson also detected periodic variability at the position of CX19 and proposed that it is an excellent candidate for a close degenerate binary caught in quiescence. ---------------- Catelan et al. (2008) announced a candidate variable on the blue extension of the HB. No coordinates were listed for the star. ---------------- Moni Bidin et al. (2008) detected a hot (25000K) close binary candidate in a radial velocity study of 145 HB stars. No coordinates were listed for the star. ---------------- Lee et al. (2015) reported that they were carrying out a search for variable stars in NGC 6752 and five other clusters (NGC 288, NGC 1851, NGC 3201, NGC 4372 and NGC 6809). ----------------- Figuera Jaimes et al. (2016) conducted a search for variables in a 41 by 41 arcsec field around the cluster centre and detected an outburst in V26, but did not discover any new variables. ======================================================================= References Alcaino, G. 1972, A&A, 16, 220 Bailey, S. I. 1902, Harvard Ann., 38 Bailyn, C. D, Rubenstein, E. P., Slavin, S. D., Cohn, H., Lugger, P., Cool, A. M., Grindlay, J. E. 1996, ApJ, 473, L31 Balona, L. A., Krisciunas, , Cousins, A. W. J. 1994, MNRAS, 270, 905 Cannon, R. D., Stobie, R. S. 1973, MNRAS, 162, 227 Catelan, M., Prieto, G. E., Zoccali, M., Weidner, C., Stetson, P. B., Moni Bidin, C., Altmann, M., Smith, H. A., Pritzl, B. J., Borissova, J., De Medeiros, J. R. 2008, ASPC, 392, 347 Clement, C. 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