NGC 6356 / C1720-177 (updated July 2013) RA: 17:23:34.93 DEC: -17:48:46.9 (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 17:23:33.72 -17:49:14.8 R0 230.6 17.35 1.7 B M 2 17:23:42.12 -17:50:41.3 R0 ---- 17.6 0.8 B Lb 3 17:23:33.30 -17:48:07.4 R0 220.0 16.9 2.8 B M mem 4 17:23:48.00 -17:48:04.5 R0 207.3 17.35 2.3 B M f? 5 17:23:17.06 -17:46:24.5 R0 219.8 17.55 1.9 B M 6 17:22:54.71 -17:47:00.2 R0 189.8 17.2 2.6 B M f? 7 17:23:34.51 -17:49:13.0 R0 ---- 15.5 0.2 V Lb 8 17:23:32.07 -17:47:59.2 R0 ---- 15.8 0.4 V Lb 9 17:23:32.47 -17:48:12.7 R0 ---- 15.6 0.4 V Lb 10 17:23:32.09 -17:49:15.3 R0 ---- 15.65 0.1 V Lb ================================================================== Supplementary Notes The RA and dec for the variables are from Samus et al. (2009). V1-6: Periods, magnitudes, amplitudes, variability types for V1-6 are from Clement & Sawyer Hogg (1977) Membership status for V3 is based on a radial velocity study by Feast (1972). Possible field status for V4 is from Lloyd Evans & Menzies (1973) and for V6 from Clement & Sawyer Hogg (1977). With a distance of 9.8 arcmin from the cluster centre, V6 is outside the tidal radius of 9.3 arcmin (Harris 1996 - 2010 update). V7-10: Magnitudes and amplitudes for V7-10 are from Lloyd Evans & Menzies (1977). They classified these stars as red variables. Since the GCVS does not use this term, we have classified them as Lb. ================================================================ Discovery of the variable stars in NGC 6356: V1-5, F1=V6 Sawyer, JRASC 47, 229 (1953) with x,y positions and ID chart for V1-5 Sawyer Hogg (1973) assigned the number V6 to F1 in her 3rd catalogue and an ID chart for V6 was published by Clement & Sawyer Hogg (1977). In the Moscow GCVS, V5 and V6 are listed as V2009 and V1995 Oph respectively.. V7-10 Lloyd Evans & Menzies (1973) who identify them as stars 34, 72, 30 and 46 of Sandage & Wallerstein (1960 - see Fig 2) Sandage & Wallerstein (1960) also labelled V1 and V3 in Fig.2 and V2, V4 and V5 in Fig. 1 of their paper. ================================================================ References Clement, C. C. & Sawyer Hogg, H. 1977, AJ, 82, 968 Feast, M. W. 1972, QJRAS, 13, 191 Lloyd Evans, T. & Menzies, J. W. 1973, IAU Colloq. No. 21, Variable Stars in Globular Clusters and in Related Systems, 151 Lloyd Evans, T. & Menzies, J. W. 1977, MNRAS, 178, 163 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Sandage, A. R. & Wallerstein, G. 1960, ApJ, 131, 598 Sawyer, H. B. 1953, JRASC, 47, 229 Sawyer Hogg, H. 1973, Publ. DDO, 3, No. 6 =====================================================================