NGC 4833 / C1256-706 (Updated April 2018) RA: 12:59:33.92 DEC: -70:52:35.4 (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 12:58:36.55 -70:44:47.8 R0 0.7501 15.86 1.00 B RR0 f?;Note 2 13:00:53.03 -70:57:44.4 R0 333.2604 12.01 2.04 V M f;Note 3 12:59:33.73 -70:52:13.5 R0 0.7445 15.1 0.63 V RR0 4 12:59:33.82 -70:51:58.1 R0 0.6555 15.3 1.06 V RR0 5 13:00:01.30 -70:53:17.7 R0 0.6294 15.3 1.20 V RR0 6 12:59:56.18 -70:50:10.4 R0 0.6540 15.6 1.10 V RR0 7 12:59:48.79 -70:52:21.4 R0 0.6684 15.4 1.10 V RR0 8 12:58:54.56 -70:44:16.7 R0 ---- -- -- CST Note 9 12:59:25.84 -70:52:30.1 R0 87.7 12.49 -- V SR? Note 10 12:59:43.24 -70:45:26.1 R0 ---- 13.72 0.47 V L? Note;f? 11 12:58:31.42 -71:05:47.2 R0 297.6 13.8 2.0 V M max;f;Note 12 12:59:38.31 -70:52:14.4 R0 0.5897 15.4 0.69 V RR0 13 13:00:29.87 -70:52:56.0 R0 0.3679 15.4 0.49 V RR1 14 12:59:31.06 -70:53:07.2 R0 0.4084 15.3 0.39 V RR1 15 12:59:19.78 -70:53:26.6 R0 0.6673 15.1 0.85 V RR0 blend 16 12:59:14.63 -70:49:59.3 R0 ---- 12.19 -- V SR? Note 17 12:59:44.03 -70:54:25.4 R0 0.3904 15.4 0.46 V RR1 18 12:59:28.27 -70:54:25.8 R0 0.4259 15.5 0.43 V RR1 19 12:59:06.02 -70:53:29.7 R0 0.3706 15.5 0.51 V RR1 Note 20 12:59:08.21 -70:52:23.8 R0 0.3002 15.7 0.10 V RR1? Note 21 12:59:50.91 -70:50:36.7 R0 0.3990 15.4 0.55 V RR1 22 12:59:45.11 -70:53:55.8 R0 0.8507 15.2 0.60 V RR0 23 12:59:44.76 -70:51:27.4 R0 0.4067 15.4 0.48 V RR1 24 12:59:36.67 -70:52:59.1 R0 0.6257 15.5 1.05 V RR0 25 12:58:55.31 -70:51:46.4 R0 0.7230 18.6 -- V EA 26 12:59:02.68 -70:52:52.3 R0 0.3179 15.6 0.16 V RR1? Note 27 12:59:13.65 -70:52:10.3 R0 0.0510 -- -- V SXP blend 28 12:59:21.20 -70:53:26.8 R0 0.8740 15.2 0.28 V RR0 29 12:59:35.32 -70:52:41.9 R0 0.0597 -- -- V SXP blend 30 12:59:42.52 -70:53:04.6 R0 0.0443 18.3 0.30 V SXP 31 12:59:47.92 -70:52:52.2 R0 0.0533 -- -- V SXP blend 32 12:59:55.04 -70:52:24.6 R0 0.0707 -- -- V SXP blend 33 12:59:57.66 -70:54:30.6 R0 0.0719 -- -- V SXP blend 34 13:00:25.08 -70:49:16.3 R0 0.3629 16.0 0.15 V EC 35 12:58:59.01 -70:52:05.1 R0 0.0375 -- -- SXP multiP 36 12:59:32.64 -70:53:15.9 R0 0.0401 -- -- SXP 37 12:59:43.16 -70:53:36.5 R0 0.3022 -- -- RR1 38 13:00:11.88 -70:51:26.4 R0 0.2571 -- -- E 39 13:01:33.10 -70:49:22.6 R0 0.2801 -- -- E 40 13:01:49.41 -70:51:42.1 R0 0.2826 -- -- E 41 13:01:29.29 -70:44:58.0 R0 0.2992 -- -- E 42 12:57:17.71 -70:47:51.0 R0 0.3137 -- -- E 43 13:00:22.56 -70:55:25.8 R0 0.3175 -- -- E 44 12:59:52.75 -70:44:32.7 R0 0.3362 -- -- E 45 13:00:43.49 -70:47:26.9 R0 0.3623 -- -- E 46 13:00:24.25 -70:56:01.4 R0 0.3807 -- -- E 47 12:59:37.69 -70:51:28.4 R0 0.4888 -- -- E 48 13:00:45.49 -70:47:38.2 R0 0.4923 -- -- E 49 13:00:55.03 -70:54:15.9 R0 1.1235 -- -- E 50 -- -- ---- -- -- SR? 51 -- -- ---- -- -- SR? 52 -- -- ---- -- -- SR? 53 -- -- ---- -- -- SR? 54 -- -- ---- -- -- SR? 54 -- -- ---- -- -- SR? 55 -- -- ---- -- -- SR? 56 -- -- ---- -- -- SR? 57 -- -- ---- -- -- SR? 58 -- -- ---- -- -- SR? 59 13:00:27.52 -70:54:01.6 R0 2.889 -- -- ? 60 12:59:14.62 -70:50:37.8 R0 4.390 -- -- ? 61 13:00:20.85 -70:49:56.4 R0 6.300 -- -- ? ==================================================================== Supplementary Notes The coordinates for V1-23 are from Samus et al. (2009) and the ones for V24-34 are from Darragh & Murphy (2012). The periods, magnitudes, amplitudes and classifications for most of V1-34 are from the study by Darragh & Murphy (2012). The exceptions are V1, V2, V8, V10 and V11 which were outside their field of view and V9 and V16 which were overexposed in their images. The data sources for these 7 stars are indicated in the notes on individual stars. All the data for V35-V61 are from Kopacki (2014). No magnitudes were published by Kopacki because the image subtraction method was used to carry out the variabiity search. Thus the membership status for the new variables is not known. ===================================================================== Notes on individual stars V1=RY Mus: The period is from Wright (1941) and the magnitudes are from Demers & Wehlau (1977). These are the values adopted for RY Mus in the Moscow GCVS. The star is located at about 9 arcmin from the cluster centre, well outside the half-light radius (2.41'). However, it is inside the tidal radius (17.8') and is a possible cluster member. The P magnitudes published by Wright (1941) and the B magnitudes of Demers & Wehlau (1977) are in the same range as those of the RR Lyrae variables that belong to the cluster. V2=RZ Mus: Feast (1966) determined a radial velocity for V2 (RZ Mus) and demonstrated that it is a field star. CCD observations of RZ Mus were obtained by Pojmanski (2002) who catalogued it as ASAS 130053-7057.7. The period, magnitude, amplitude and classification are from Richards et al. (2012) based on the Pojmanski data. V8: Wright (1941) was unsure of the variability of this star and Demers & Wehlau (1977) concluded that the apparent variability occurred because the star had a close companion. V8 is now considered to be constant. V9, V16: These stars are both near the red giant tip and are probably semi-regular variables that are cluster members. Their distances from the cluster centre are 0.7' and 2.8' respectively. The period for V9 was derived by Wright (1941). No period has been determined for V16; it was discovered after Wright carried out her study. The V magnitudes for V9 (#651) and V16 (#1740) were derived by Melbourne et al. (2000). V10: The data are from the the AAVSO VSX (Watson et al. 2006). Demers & Wehlau (1977) observed V10 and their photographic B,V magnitudes indicate that the star lies redward of the giant branch on Menzies' (1972) CM diagram. They did not have enough observations to derive a period. V10 was outside the field of view in Menzies study and also in the study by Melbourne et al. (2000). It is located at about 7 arcminutes from the cluster centre, well outside the half-light radius (2.41'), but inside the tidal radius (17.8') according to the 2010 revision of the Harris (1996) catalogue. It is unlikely that V10 is a cluster member. V11= FQ Mus According to the Moscow GCVS, FQ Mus is a Mira variable. It is unlikely that it is a cluster member because Mira variables are associated with metal rich populations and NGC 4833 has [Fe/H]= -1.85 according to the 2010 revision of the Harris (1996) catalogue. With r>14 arcmin from the cluster centre, it is inside the tidal radius (17.8'), but well beyond the half-light radius (2.41'). The period, magnitude and amplitude for V11 (FQ Mus) are from Goossens et al. (1980) who listed the star as V10 in their investigation of 22 long period variables in a Galactic field centred at RA = 13 hours. V19: There was a typo in the RA listed by Samus et al. (2009). They listed 12:29:06.02 instead of 12:59:06.02. This incorrect RA was also listed in the 2012 version of this electronic catalogue. The revised RA listed above is in good agreement with the value published by Kopacki (2014) and by Darragh & Murphy (2012). V20, V26: The periods, magnitudes and amplitudes for these two variables are from Darragh & Murphy (2012) who classified them both as possible second overtone pulsators (RR2, RRe). However, they both might be short period RR1 variables that exhibit changes in amplitude due to non-radial oscillations. Olech et al. (2001) identified stars with these properties among the short period RR1 variables in several other clusters. ====================================================================== Discovery of the variable stars in NGC 4833: V1-2 discovered by Bailey with RA and dec (epoch 1900) and Harvard variable numbers (HV3692 and HV3693) and announced by Shapley (1923). Their x,y positions were later published by Wright (1941). The numbers V1 and V2 were assigned by Sawyer (1955) in her 2nd catalogue. She also noted that these stars were RY Mus and RZ Mus respectively. V3-11 discovered by various investigators at Harvard and announced by Wright (1941) with x,y coordinates and Harvard variable numbers. The numbers V3-11 were assigned by Sawyer (1955) who also listed their Harvard numbers. V12-16 Fourcade et al. (1966) with x,y coordinates and an ID chart Fourcade et al. also labelled V1-7 and V9-11 on their prints. V17-24 = B57, B84, B105, B121, B193, C80, C308, D199 on charts published by Menzies (1972) who classified them as possible variables. The numbers V17-24 were assigned by Demers & Wehlau (1977) who published an ID chart for all of V1-24 except V11 (FQ Mus) which was outside of their field of view. They also commented that V5 was incorrectly identified on Menzies' chart. V25-34 = NV1-10 Darragh & Murphy (2012) with RA and dec The numbers V25-34 have been assigned in this catalogue. V35-49 = n35-49 V59-61 = n59-61 Kopacki (2014) with RA and dec (2000) V50-58 Kopacki also announced the discovery of 9 new variable red giants at the tip of the RG branch. No further data were provided for these stars.  They are listed as V50 to V58 in the above table. ==================================================================== References Alcaino, G. 1971, A&A, 13, 287 Darragh, A. N. & Murphy, B. W. 2012, J. Southeastern Assoc. Research Ast., 6, 72 Demers, S. & Wehlau, A. 1977, AJ, 82, 620 Feast, M. W. 1966, Obs, 86, 120 Fourcade, C. R., Laborde, J. R., Albarracin, J. 1966, Atlas y Catalogue de Estrellas Variables en Cumulos Globulares al sur de -29 degrees, Cordoba Goossens, M., Stoop, C., Waelkens, C. 1980, IBVS, 1760 Harris, W. E. 1996, AJ, 112, 1487 Kopacki, G. 2014, arXiv:1401.4822v1 = 2013, IAUS, 301, 441 Melbourne, J., Sarajedini, A., Layden, A., Martins, D. H. 2000, AJ, 120, 3127 Menzies, J. 1972, MNRAS, 156, 207 Olech, A., Kaluzny, J., Thompson, I. B., Pych, W., Krzeminski, W., Schwarzenberg-Czerny, A. 2001, MNRAS, 321, 421 Pojmanski, G. 2002, Acta A., 52, 397 Richards, J. W., Starr, D. L., Miller, A. A., Bloom, J. S., Butler, N. R., Brink, H., Crellin-Quick, A. 2012, ApJS, 203, 32 Samus, N. N., Kazarovets, E. V., Pastukhova, E. N., Tsvetkova, T. M., Durlevich, O. V. 2009, PASP, 121, 1378 Sawyer, H. B. 1955, Publ. DDO, 2, No. 2 Shapley, H. 1923, Harv. Bull., 792, 3 Watson, C. L., Henden, A. A., Price, A. 2006, SASS, 25, 47 Wright, F. W. 1941, Harv. Bull., 792, 3 ====================================================================