NGC 6341 / C1715+432 / Messier 92 (Updated July 2012) RA: 17:17:07.39 DEC: +43:08:09.4 (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 17:17:18.99 +43:08:54.9 R0 0.7028 15.02 0.86 V RR0 2 17:17:15.64 +43:09:22.4 R0 0.6439 15.08 0.85 V RR0 3 17:17:12.00 +43:12:25.3 R0 0.6377 15.09 1.17 V RR0 4 17:17:00.35 +43:09:09.1 R0 0.6289 15.12 0.84 V RR0 5 17:17:14.93 +43:07:19.2 R0 0.6197 15.12 0.98 V RR0 6 17:17:10.87 +43:08:56.0 R0 0.6000 14.96 1.09 V RR0 7 17:17:07.61 +43:07:21.6 R0 1.0614 14.15 0.64 V CW 8 17:17:26.24 +43:11:42.5 R0 0.6728 15.05 0.67 V RR0 9 17:17:09.09 +43:07:24.2 R0 0.6085 15.13 1.19 V RR0 10 17:17:14.93 +43:08:49.3 R0 0.3773 15.11 0.48 V RR1 11 17:17:13.98 +43:07:05.8 R0 0.3084 15.10 0.62 V RR1 12 17:17:10.25 +43:06:34.8 R0 0.4100 15.06 0.41 V RR1 Note 13 17:17:21.48 +43:07:13.9 R0 0.3130 15.13 0.15 V RR1 14 17:16:38.24 +43:12:14.5 R0 0.3462 14.650 0.40 P EC f;Note 15 17:17:07.32 +43:09:30.9 R0 ---- -- -- NV 16 17:16:47.91 +43:06:16.0 R0 ---- -- -- NV Note 17 17:16:59.12 +43:08:23.9 R0 ---- -- -- NV 18 17:16:57.22 +43:07:11.5 R0 ---- -- -- NV 19 17:16:58.51 +43:07:44.3 R0 ---- -- -- NV 20 17:17:04.4 +43:07:45 R0 ---- -- -- NV 21 17:17:07.2 +43:08:53 R0 ---- -- -- NV 22 17:17:07.4 +43:07:50 R0 ---- -- -- NV 23 17:17:07.4 +43:08:33 R0 ---- -- -- NV 24 17:17:07.5 +43:08:41 R0 ---- -- -- NV 25 17:17:09.73 +43:08:03.5 R0 0.7004 -- 0.75 V RR0 26 17:17:10.73 +43:09:58.8 R0 ---- -- -- NV 27 17:17:11.1 +43:08:08.1 R0 ---- -- -- NV 28 17:17:12.2 +43:08:27 R0 ---- -- -- NV 29 17:17:07.94 +43:08:02.8 R0 0.5959 -- 0.95 V RR0 30 17:17:07.53 +43:08:06.0 R0 0.5283 -- 1.59 V RR0 31 17:17:06.77 +43:08:27.3 R0 0.3982 -- 0.52 V RR1 32 17:17 04.60 +43:08:42.2 R0 0.3246 -- 0.21 V RR1 33 17:17 03.85 +43:08:13.7 R0 0.0751 17.29 0.68 V SXP 34 17:17 09.95 +43:07:42.7 R0 0.0830 17.13 0.34 V SXP 35 17:17:09.49 +43:08:38.0 R0 0.0549 -- -- SXP 36 17:17:06.52 +43:07:57.4 R0 0.0475 17.88 0.04 V SXP 37 17:17:06.33 +43:09:48.3 R0 0.0402 -- -- SXP 38 17:17:04.59 +43:08:45.2 R0 0.0729 -- -- SXP 39 17:17:04.24 +43:08:50.4 R0 0.0359 -- -- SXP ====================================================================== Supplementary Notes A good summary of investigations of the variable stars in M92 was given by Kopacki (2001). V1-32 The RA and dec are from Samus et al. (2009). The periods, magnitudes, amplitudes and classifications are from Kopacki (2001) unless indicated otherwise in the notes on individual stars. V14 and V16 were outside his field of view. V33-39 All the data are from Kopacki (2007). ======================================================================= Notes on individual stars V12: Some confusion about the identity of this star arose because there was an error in the sign of the x coordinate published by Hachenberg (1939). It should have been +29.9" instead of -29.9". The incorrect value was published by Sawyer in her three catalogues (Sawyer 1939, 1955; Sawyer Hogg 1973). Bartolini et al. (1968) discovered the error and recognized that V12 was the same star as Nassau's V10 which had been designated as V15 by Sawyer (1939, 1955). V14: This star was classified as W Ursae Majoris by Hachenberg (1939) who derived a period of 0.346178 days and noted that it did not belong to the cluster. The non-member status was later confirmed in proper motion studies by Rees (1992) and by Tucholke et al. (1996). The period, magnitude and amplitude listed above are from Bartolini et al. (1968) V16: This was Nassau's suspected variable V15. It was subsequently established by Arp et al. (1953) that it was not variable and this result was confirmed by Walker (1955). ==================================================================== Discovery of the variable stars in M92: V1-14 Hachenberg (1939) with x,y positions and numbers from the Hopman (1930) catalogue. Hachenberg noted that these variables had been previously discovered by Woods (1922) and Guthnick & Prager (1925). Woods announced the discovery and published x,y coordinates for the variable now known as V11. Guthnick & Prager (1925) announced that they had discovered 13 variables in M92, but did not publish any positions. The numbers V1-14 were assigned by Hachenberg. Most of these variables were independently discovered by Nassau (1938) who published an ID chart. However, the Nassau and Hachenberg numbering systems were different. Sawyer (1939, 1955) adopted Hachenberg's (1939) system in her catalogues. A table with cross correlations between the different numbering systems was published by Kadla et al. (1983). V15 = V12 of Nassau (1938) who labelled it on a chart The number V15 was assigned by Sawyer Hogg (1973) in her 3rd catalogue. In her first two catalogues (Sawyer 1939, 1955), she designated this star as V16 and Nassau's V10 was designated as V15. Bartolini et al. (1968) later discovered that Nassau's V10 was the same star as Hachenberg's V12. Sawyer (1939, 1955) had not realized this because the x coordinate Hachenberg (1939) published for his V12 was incorrect. V16-17 = Nassau's (1939) suspected variables V15-16 which he labelled on an ID chart. Their x,y coordinates were derived by Kadla et al. (1983) and the numbers V16-17 were later assigned by Clement et al. (2001). V18-28 Kadla et al. (1983) with x,y coordinates and an ID chart They also published a table with cross correlations between the numbering systems of Sawyer (1939), Sawyer Hogg (1973) and Nassau (1938) for V1-17. V29-34 Kopacki (2001) with x,y coordinates and an ID chart V35-39 Kopacki (2007) with RA, dec and ID chart Kopacki also provided ID for 3 blue stragglers suspected of variability. ---------------------------------------------------------------- Walker (1955) suspected that three stars near the RG tip might be variable, but Welty (1985) did not detect any variablility with B amplitude greater than 0.2 mag for any of them. ---------------------------------------------------------------------- Shara et al. (1994) surveyed the cluster for erupting dwarf novae but did not detect any; they established an upper limit based on their results. Tuairisg et al. (2003) later announced a possible dwarf nova candidate. ----------------------------------------------------------------------- Lynch & Ransom (2011) conducted a search for pulsars, but did not find any in M92. ============================================================ References Bartolini, C., Battistini, P., Nasi, E. 1968, Bologna Publ., 9, No. 15 Clement, C. M., Muzzin, A., Dufton, Q., Ponnampalam, T., Wang, J., Burford, J., Richardson, A., Rosebery, T. 2001, AJ, 122, 2587 Guthnick, P. & Prager, R. 1925, Sitz. d. Preuss., Akad. Wiss., 28, 508 Hachenberg, O. 1939, Z. Astrophys. 18, 49 Hopmann, J. 1930, Mem. Pont. Acc., 14 Kadla, Z. I., Yablokova, N. V., Gerashchenko, A. N., Spasova, N. 1983, Per. Zvez., 21, 827 Kopacki, G. 2001, A&A, 369, 862 Kopacki, G. 2007, Acta A, 57, 49 Lynch, R. S. & Ransom, S. M. 2011, ApJ, 730, L11 Nassau, J. J. 1938, ApJ, 87, 361 Rees, R. F. 1992, AJ, 103, 1573 Sawyer, H. B. 1939, Publ. DDO, 1, No. 4 Sawyer, H. B. 1955, Publ. DDO, 2, No. 2 Sawyer Hogg, H. 1973, Publ. DDO, 3, No. 6 Shara, M. M., Bergeron, L. E., Moffat, A. F. J. 1994, ApJ, 429, 767 Tuairisg, S. O., Butler, R. F., Shearer, A., Redfern, R. M., Butler, D., Penny, A. 2003, MNRAS, 345, 9600 Tucholke, H.-J., Scholz, R.-D., Brosche, P. 1996, A&A, 312, 74 Walker, M. F. 1955, AJ, 60, 197 Welty, D. E. 1985, AJ, 90, 2555 Woods, I. E. 1922, Harv. Bull. 773, 1 (reported by H. Shapley) ================================================================