NGC 5946 / C1531-504 (Upated January 2013) RA: 15:35:28.52 DEC: -50:39:34.8 (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 15:35:48.09 -50:41:24.0 R0 ---- -- -- L 2 15:35:23.13 -50:39:50.8 R0 ---- -- -- CST? 3 15:35:37.86 -50:40:08.2 R0 0.70 17.9 1.3 B RR0 4 15:35:05.83 -50:40:29.7 R0 ---- -- -- L 5 15:35:26.00 -50:38:51.1 R0 ---- -- -- E? 6 15:35:29.37 -50:41:07.6 R0 0.602 18.1 1.3 B RR0 7 15:35:30.91 -50:39:44.7 R0 ---- -- -- RR? blend ======================================================================== Supplementary Notes The RA and dec for the variables are from Samus et al. (2009). The remaining data are from Liller (1983) who also presented data for 12 field variables in the cluster vicinity. NGC 5946 has not been well studied. It is a difficult cluster to observe because it lies near the galactic plane and is heavily reddened. In the 2010 update to his catalogue of GC parameters, Harris (1996) lists [Fe/H] =-1.29 based on observations by Armandroff & Zinn (1988) and a CMD published by Alcaino et al. (1991) shows a predominantly blue HB. On the basis of the giant branch slope, both Alcaino et al. (1991) and Davidge (1985) have concluded that the metallicity of this cluster is lower than generally assumed. ======================================================================= Discovery of the variable stars in NGC 5946: V1-3 = Fourcade #1, 2 and 4 Fourcade et al. (1966) announced 8 variables in the field of NGC 5946 and published x,y coordinates and an ID chart. Sawyer Hogg (1973) designated Fourcade's V1, 2 and 4 as V1, 2 and 3 in her 3rd catalogue and considered the other 5 to be field variables. V4-7 Liller (1983) with x,y coordinates and an ID chart Liller also announced an additional 7 field variables. ======================================================================== References Alcaino, G., Liller, W., Alvarado, F., Wenderoth, E. 1991, AJ, 102, 1371 Armandroff, T. E. & Zinn, R. 1988, AJ, 96,92 Davidge, T. J. 1995, AJ, 110, 1177 Fourcade, C. R., Laborde, J. R., Albarracin, J. 1966, Atlas y Catalogue de Estrellas Variables en Cumulos Globulares al sur de -29 degrees, Cordoba Harris, W. E. 1996, AJ, 112, 1487 Liller, M. 1983, AJ, 88, 404 Sawyer Hogg, H. 1973, Publ. DDO, 3, No. 6 ========================================================================