NGC 6779 / C1914+300 / Messier 56 (Updated April 2010) RA: 19:16:35.57 DEC: +30:11:00.5 (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 or P (for photographic). 61-65 A5 Type of variable (draft 2006 GCVS classifications) NV denotes not variable 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 19:16:39.34 +30:12:16.5 R0 1.5100 16.05 1.2 B CW mem 2 19:16:37.35 +30:11:35.2 R0 ---- 15.49 0.6 B NV Note 3 19:16:37.83 +30:12:33.9 R0 ---- 14.84 0.9 B SR mem;Note 4 19:16:27.46 +30:08:21.1 R0 0.7349 16.55 0.7 B RR0 5 19:16:36.60 +30:08:47.3 R0 ---- 14.72 0.8 B SR Note 6 19:16:35.78 +30:11:38.8 R0 90.00 13.75 2.0 B RVB mem 7 19:16:58.74 +30:07:30.9 R0 ---- 16.05 1.0 B Lb f 8 19:16:28.70 +30:05:24.2 R0 ---- 16.45 0.9 B Lb f 9 19:16:50.11 +30:19:58.9 R0 ---- 16.05 0.8 B Lb f 10 19:16:02.71 +30:12:25.8 R0 0.5989 17.5 1.5 B RR0 f 11 19:16:03.66 +30:15:40.4 R0 0.0756 16.2 1.1 B SXPHE f 12 19:16:17.24 +30:09:23.6 R0 0.9061 16.85 1.0 B RR0 13 19:16:38.72 +30:10:59.1 R0 38.96 13.61 0.13 R SR? 14 19:16:29.83 +30:12:27.2 R0 0.3808 15.69 0.27 R RR1 ======================================================================== Supplementary Notes and References V1-12: The periods, magnitudes and membership status are from Wehlau & Sawyer Hogg, (1985, AJ 90, 2514). Their membership status for V1, V3, V5, V7, V8, V9 and V11 was based on a proper motion study by Rishel et al. (1981, A&A Suppl. 45, 443,); V6 based on a radial velocity study by Joy (1949, ApJ 110, 105) and V10 based on its faint mean magnitude. The positions are from Samus et al. (2009, PASP 121, 1378). V7-11 are V0487, V0485, V0486, V0483 and V0484 resepctively in the Moscow GCVS (Samus et al.) V13-14: The data are from the discovery paper by Pietrukowicz et al. (2008, Acta A 58, 121). They classified V13 as a pulsating variable, possibly on the AGB - no color information was available. ========================================= Notes on individual stars V2: In his discovery paper, Shapley (1920, ApJ 52, 73) listed this star as a suspected variable and no one has confirmed its variability since then. Rosino (1944, Bologna Pub. IV, No. 7) was unable to estimate its magnitudes because it was in a crowded region near the cluster centre and not resolved on his plates. Wehlau and Sawyer Hogg (1990) noted that its range in their data was smaller than the other SR/irregular variables. Russeva (1999, IBVS 4727) and Pietrukowicz et al. (2008, Acta A 58, 121) did not detect any variability so it is classified as non-variable. V3,V5: These stars were classified as SR variables by Rosino (1949, Bologna Publ. V, No. 12 = 1950, Mem. Soc. Astron. Italiana 21, 55) and by Wehlau & Sawyer Hogg (1990). Later, Russeva (1999, IBVS 4727) derived periods of 41.7 and 31.6 days respectively, but different periods were derived by Horne (2005, JAVSO 34, 61) and by Pietrukowicz et al. (2008, Acta A 58, 121). ========================================================================= Discovery of the variable stars in M56: V1-3 Shapley (1920, ApJ 52, 73) with x,y coordinates and ID chart. V2 was a suspected variable. V3 was independently discovered by Davis (1917, PASP 29, 210) who listed Delta RA & dec, but the x,y coordinates assigned by Shapley were different. V4-9 Sawyer (1940, DDO Publ. 1, No. 5, p 179) with x,y coordinates and an ID chart for V1-9 as well as the numbers assigned in Kustner's (1920, Bonn Veroff. no. 14) catalogue. Later (Sawyer 1949, JRASC 43, 38), she classified V6 as an RV Tauri type. V10-11 Rosino (1944, Bologna Publ. IV, No. 7 = Mem. Soc. Astron. Italiana Vol. 16, 237) with x, y coordinates and finding chart for V1-11 (V2 not included) V12 Sawyer (1953, JRASC 47, 229) with Kustner # (68) and x,y coordinates V13-14 Pietrukowicz et al. (2008, Acta A 58, 121) with RA and dec ------------------ Additional variables In a series of papers, Kurochkin (1968, Per. Zvez. 16, 460; 1970, Per. Zvez. 17, 186; 1971, Per. Zvez. 17, 620 and 1972, Per. Zvez. 18, 497) identified a total of 82 new variables in a field within 10 by 10 degrees of the cluster centre. Wehlau & Sawyer Hogg (1985, AJ 90, 2514) concluded that none were cluster members. Russeva (1999, IBVS 4727) announced the variability of four red giants: Kustner numbers 204, 235, 251 and one of [343 or 1343 - this is ambigous in the paper] and derived periods in the range of 22 to 33 days for all of them. Pietrukowicz et al. (2008, Acta A 58, 121) stated that their analysis did not indicate any variability for Kustner 204, but they did not mention the other three.