NGC 1261 / C0310-554 (updated July 2017) RA: 03:12:16.21 DEC: -55:12:58.4 (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, 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 03 12 12.51 -55 13 25.5 R0 ---- -- -- CST 2 03 12 11.28 -55 12 22.0 R0 0.5522 16.81 1.4 B RR0 3 03 12 21.78 -55 13 50.7 R0 0.5370 16.21 1.3 B RR0 4 03 12 18.56 -55 13 28.4 R0 0.4929 16.09 1.1 B RR0 Note 5 03 12 11.93 -55 13 01.9 R0 0.5126 15.95 1.8 B RR0 6 03 12 25.05 -55 13 08.6 R0 0.5641 17.01 1.3 B RR0 7 03 11 58.44 -55 10 37.3 R0 0.3335 16.88 0.8 B RR1 8 03 12 00.44 -55 15 16.4 R0 0.5382 17.10 1.6 B RR0 9 03 12 20.40 -55 13 35.3 R0 0.2972 16.69 0.9 B RR1 10 03 12 21.99 -55 11 45.9 R0 0.5934 17.09 1.5 B RR0 11 03 12 05.50 -55 11 27.7 R0 0.6622 17.17 0.7 B RR0 12 03 12 26.15 -55 12 45.8 R0 0.6103 17.16 1.1 B RR0 13 03 12 07.01 -55 14 33.1 R0 0.3376 16.93 0.7 B RR1 14 03 12 09.75 -55 14 07.6 R0 0.5739 16.89 1.2 B RR0 15 03 12 02.50 -55 10 48.1 R0 80.5000 15.63 1.1 B SR? Note 16 03 12 13.90 -55 13 12.9 R0 0.5262 16.95 1.4 B RR0 17 03 12 15.48 -55 12 36.6 R0 0.5130 16.85 0.6 B RR0 18 03 12 13.80 -55 12 40.6 R0 ---- -- -- CST Note 19 03 12 18.19 -55 12 44.7 R0 0.653 16.6 1.4 B RR0 Note 20 03 12 19.31 -55 13 00.4 R0 0.5412 16.55 1.0 B RR0 21 03 12 14.47 -55 12 31.3 R0 0.3344 17.05 0.3 B RR1 22 03 12:16.49 -55:13:38.1 R0 0.302 -- -- RR1 23 03:12:15.69 -55:12:40.7 R0 ---- -- -- SR? Note 24 03:12:14.43 -55:13:34.8 R0 0.626 -- -- RR0 25 03:12:17.17 -55:11:22.7 R0 0.0535 -- -- SXPHE Note 26 03:12:17.05 -55:12:43.9 R0 0.0799 18.66 0.12 r SXPHE 27 03:12:14.65 -55:13:06.5 R0 0.341 -- -- RR1 28 03:12:13.53 -55:13:00.8 R0 0.287 -- -- RR1 29 03:12:13.05 -55:13:20.5 R0 0.593 -- -- RR0 30 03:12:16.58 -55:12:54.0 R0 0.0591 18.42 0.07 r SXPHE 31 03:12:18.70 -55:14:16.0 R0 ---- 20.59 0.16 r EC? P>0.1;f? ================================================================ Supplementary Notes The RA and dec for V1-21 are from Samus et al. (2009). The periods, magnitudes, amplitudes and variable types for V1-15 are from Wehlau & Demers (1977). They also published an ID chart for these variables. Salinas et al. (2007) confirmed the CST status for V1. The periods, magnitudes, amplitudes and variable types listed for V16-21 are from Wehlau et al. (1977) - except for V18 and V19 as indicated in the notes on individual stars. The periods and classifications for V22-30 are from Salinas et al. (2007). The remaining data are from a later study by Salinas et al. (2016). They published mean "r" magnitudes and amplitudes. However, many of these values have not been listed here because they were considered to be uncertain. Salinas et al. (2016) also published RA and dec for all except V23 and V25. The data for V31 are from the discovery paper by Salinas et al. (2016). A study by Simunovic et al. (2014) indicates that NGC 1261 has a large population of blue stragglers which probably includes a significant number of close binaries and SX PHe variables that have not yet been discovered. Kravtsov et al. (2010) published UBVI photometry for 5481 stars in a 14 by 14 arcmin field around the cluster. ================================================== Notes on individual stars V4: Wehlau et al. (1977) pointed out that the previously published x,y coordinates for V4 were incorrect and attributed the error to incorrect identification on the chart published by Laborde & Fourcade (1966). V15: According to Wehlau & Demers (1977), this star is near the RG tip. They found the period to be well determined, with no irregularity, which they considered to be unusual for a star with a period of that length. We tentatively classify it as SR because it does not have the properties of a Mira or a slow irregular variable. There was a typo in the x coordinate listed for V15 in our earlier on-line catalogue. The error was pointed out by Samus 2009 - private communication.) V18, V19: The CST status for V18 and the period for V19 are from Salinas et al. (2007). V23: The light curve that Salinas et al. (2007) plotted for V23 resembles their curve for V15. We have therefore tentatively classified this star as SR. The RA and dec listed above for V23 have been derived from the x,y coordinates published by Salinas et al. (2007). According to the Vizier catalogue, this position coincides with a 2MASS source. V25: The RA and dec listed above for V25 have been derived from the x,y coordinates published by Salinas et al. (2007). According to the Vizier catalogue, this position coincides with a blue straggler star observed by Kravtsov et al. (2010). ================================================================== Discovery of the variable stars in NGC 1261: V1-11 Fourcade et al. (1966) with x,y coordinates and an ID chart In a separate paper, Laborde & Fourcade (1966) had announced V1-6 with x,y coordinates and an ID chart. It turned out that they had a different identification for V4 on their two ID charts and neither was correct. This was pointed out by Wehlau et al. (1977) who derived the correct coordinates. The ID chart for V1-15 published by Wehlau & Demers (1977) shows the correct position for V4. V12-15 Bartolini et al. (1972) with x,y coordinates. Bartolini announced these new variables in an earlier paper (Bartolini et al. 1971), but with a different numbering system. When they wrote their 1971 paper, they were aware of the discovery of V1-6, but not V7-11. The numbering system assigned in their 1972 paper supersedes the older one. The sign of the y coordinate they listed for V12 was incorrect. It should have been +10.5 instead of -10.5. This incorrect value also appeared in Sawyer Hogg's 3rd catalogue. The error was later pointed out by Wehlau et al. (1977). V16-21 Wehlau et al. (1977) with x,y coordinates. V22-30 Salinas et al. (2007) with x,y coordinates and an ID chart. No magnitudes or amplitudes were derived because they used the image subtraction technique. They also re-discovered all of the previously announced variables except V1 and V18, which they considered to be non-variable. V31 Salinas et al. (2016) with RA and dec (J2000) ======================================================================= References Bartolini, C., Grilli, F., Robertson, J. W. 1971, IBVS, 594 Bartolini, C., Grilli, F., Morisi, F. 1972, IBVS, 662 Fourcade, C. R., Laborde, J. R., Albarracin, J. 1966, Atlas y Catalogue de Estrellas Variables en Cumulos Globulares al sur de -29 degrees, Cordoba Laborde, J. R. & Fourcade, C. R. 1966, Mem. S. A. I., 37, 251 Kravtsov, V., Alcaino, G., Marconi, G., Alvarado, F. 2010, A&A, 516, A23 Salinas, R., Catelan, M., Smith, H. A., Pritzl, B. J. 2007, IBVS, 5744 Salinas, R., Contreras Ramos, R., Strader, J., Hakala, P., Catelan, M., Peacock, M. B., Simunovic, M. 2016, AJ, 152, 55 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Simunovic, M., Puzia, T. H., Sills, A. 2014, ApJ, 795, L10 Wehlau, A. & Demers, S. 1977, A&A, 57, 251 Wehlau, A., Flemming, T., Demers, S., Bartolini, C. 1977, IBVS, 1361 =========================================================================