NGC 4147 / C1207+188 (Updated June 2020) RA: 12:10:06.30 DEC: +18:32:33.5 (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, 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 12:09:59.38 +18:31:48.4 R0 0.5004 17.00 1.15 V RR0 2 12:10:04.96 +18:32:04.5 R0 0.4932 17.03 1.02 V RR0 3 12:10:04.38 +18:31:58.4 R0 0.2805 17.00 0.51 V RR1 4 12:10:06.39 +18:32:50.1 R0 0.3000 16.97 0.45 V RR1 5 12:10:07.38 +18:32:35.1 R0 ---- -- -- CST 6 12:10:08.51 +18:33:00.0 R0 0.6097 16.92 0.85 V RR0 7 12:10:06.66 +18:32:39.7 R0 0.5142 16.80 1.06 V RR0 8 12:10:06.95 +18:32:34.8 R0 0.2787 16.86 0.40 V RR1 9 12:10:08.24 +18:32:59.7 R0 ---- -- -- CST 10 12:10:03.74 +18:31:48.4 R0 0.3523 16.99 0.40 V RR1 11 12:10:05.53 +18:31:51.8 R0 0.3874 16.86 0.41 V RR1 12 12:10:06.70 +18:32:28.4 R0 0.5047 16.80 1.12 V RR0 13 12:10:06.37 +18:32:14.1 R0 0.4083 16.66 0.45 V RR1 14 12:10:06.94 +18:32:32.4 R0 0.3564 16.94 0.37 V RR1 15 12:10:07.00 +18:32:24.8 R0 ---- -- -- CST 16 12:10:07.35 +18:32:40.1 R0 0.3723 16.57 0.21 V RR1 17 12:10:10.67 +18:34:51.2 R0 0.3712 16.93 0.34 V RR1 18 12:10:05.63 +18:32:11.6 R0 24.8 13.929 0.2 V SR Note 19 12:10:21.98 +18:35:02.0 R0 0.2739 17.03 0.28 V RR1 20 12:10:06.12 +18:32:33.1 R0 ---- 14.98 -- V SR Note 21 12:10:05.15 +18:33:22.0 R0 0.1928 18.483 0.366 V EW 22 12:10:02.97 +18:33:15.3 R0 0.5391 17.365 0.415 V E 23 12:10:00.91 +18:33:14.7 R0 0.4744 16.677 0.155 V ? f;Note 24 12:10:06.53 +18:33:02.2 R0 0.2904 16.991 0.151 V EA 25 12:10:08.61 +18:32:50.1 R0 0.2392 17.673 0.182 V E 26 12:09:53.77 +18:32:49.9 R0 0.3433 16.796 0.157 V ? f;Note 27 12:10:07.63 +18:32:48.6 R0 0.2289 18.302 0.351 V EW 28 12:10:06.41 +18:32:42.9 R0 0.2960 16.439 0.343 V RR1 29 12:10:06.61 +18:32:37.7 R0 0.3044 17.003 0.515 V RR1 30 12:10:07.82 +18:32:35.9 R0 0.3236 17.393 0.131 V E 31 12:10:06.49 +18:32:35.4 R0 0.2821 16.547 0.000 V RR1 32 12:10:06.57 +18:32:27.3 R0 0.2964 16.361 0.478 V RR1 33 12:10:06.03 +18:32:26.5 R0 0.2966 17.289 0.616 V RR1 34 12:10:01.12 +18:32:23.4 R0 0.4381 19.419 0.722 V RR1? f?;Note 35 12:10:06.65 +18:32:22.5 R0 0.2754 17.066 0.481 V RR1 36 12:10:04.93 +18:32:14.8 R0 0.3228 17.350 0.123 V EA 37 12:10:07.43 +18:32:06.4 R0 0.2913 15.653 0.079 V EA 38 12:10:03.90 +18:31:56.5 R0 0.1256 18.515 0.346 V SXPhe 39 12:10:04.05 +18:31:51.6 R0 0.1049 18.081 0.329 V EA 40 12:10:07.82 +18:31:49.7 R0 0.1774 18.707 0.385 V EW 41 12:10:06.55 +18:31:48.8 R0 0.5407 17.512 0.167 V EW 42 12:10:08.35 +18:31:48.6 R0 0.2855 17.178 0.168 V RR1 43 12:10:03.17 +18:31:28.4 R0 0.2552 18.183 0.285 V RR1? f?;Note 44 12:10:12.22 +18:29:41.4 R0 0.2321 18.505 0.268 V EA? f;Note 45 12:10:09.92 +18:31:04.0 R0 0.3139 18.920 0.297 V ? 46 12:10:04.07 +18:32:24.1 R0 0.4763 18.420 0.502 V EA 47 12:10:04.56 +18:32:14.7 R0 0.4243 16.982 0.063 V EW ========================================================================= Supplementary Notes CCD investigations of the variable stars in NGC 4147 have been carried out by Arellano Ferro et al. (2004, 2018), by Stetson et al. (2005) and by Lata et al. (2019). In the above table, the data for V1-19 are from Stetson et al. (2005), V20 are from Arellano Ferro et al. (2018), V21-47 are from Lata et al. (2019), unless indicated otherwise in the notes on individual stars. In the past, it has been suggested that NGC 4147 might be connected with the Sgr dwarf galaxy, but a proper motion study by Sohn et al. (2018) based on HST data indicated that this is not the case. Furthermore Riley and Strigari (2020) concluded that it is unlikely that NGC 4147 is a Sgr cluster, based on the fact that it is nearly counter-orbiting with respect to Sagittarius. However, Bellazzini et al. (2020) suggested that the cluster might be associated with a more ancient wrap of the stream and that it would be worthwhile to attempt a spectroscopic confirmation. ===================================================================== Notes on individual stars V18: Arellano Ferro et al. (2004) classified V18 as a possible foreground RR Lyrae variable, but Stetson et al. (2005) did not confirm its variability. However, a later study by Arellano Ferro et al. (2018) has shown that V18 is an SR variable and cluster member. It is located at the red giant tip in the CM diagram. The data in the above table are from Arellano Ferro et al. (2018). V20: There are two NGC 4147 stars labelled as V20 in the literature. The first one was published by Arellano Ferro et al. (2018) with RA, dec and ID chart. It was announced in a Note Added in Proof in their Rev. Mex. A&A paper. Later, Arellano Ferro (2020 - private communication) pointed out that the RA and dec published in the 2018 paper were incorrect. The correct values are listed in the above table. Meanwhile, in their investigation of NGC 4147, Lata et al. (2019) anounced 28 new variables which they numbered from V20 to V47. They classified their V20 as a possible eclipsing binary and derived RA = 12:10:12.59; dec = 18:34:36.7. The star has V=13.436 mag which makes it brighter than any other star in the cluster. Furthermore, they determined that it had a membership probability of zero based on its proper motion. Thus their V20 is clearly a field star. V20 in the above table refers to the V20 announced by Arellano Ferro et al. (2018). V23: Lata et al. (2019) classified V23 as a field star, based on its geometric membership probability. With a radial distance of 1.464 arcminutes from the cluster centre, it is located well beyond the half light radius, 0.48 arcminutes and much further from the centre than most of the other variables. They did not list a variability type, but the V23 light curve suggests an eclipsing binary of type EA. V26: Lata et al. (2019) classified V26 as a field star, based on its geometric membership probability. With a radial distance of 3.0 arcminutes from the cluster centre, it is located well beyond the half light radius, 0.48 arcminutes and further from the cluster centre than almost all of the other variables. V34: Lata et al. (2019) classified V34 as a suspected field star. It appears to be an RR Lyrae variable, but its location on the CM diagram is not appropriate for cluster membership. V43: Lata et al. (2019) classified V43 as a suspected field star. It appears to be an RR Lyrae variable, but its location on the CM diagram is not appropriate for cluster membership. V44: Lata et al. (2019) classified V44 as a field star, based on its geometric membership probability. With a radial distance of 3.2 arcminutes from the cluster centre, it is located well beyond the half light radius, 0.48 arcminutes and further from the cluster centre than any of the other variables. Furthermore, its location on the CM diagram is 0.5 mag (V-R) to the red of the giant branch. ==================================================================== Discovery of the Variable Stars in NGC 4147: V1-3 Baade (1930) with x,y positions and ID chart V4 Davis (1917) with x,y position V5-14 Sandage & Walker (1955) and/or Newburn (1957) with ID charts for V1-V14 published by Sandage & Walker V15-17 and non-variable status for V9 Newburn (1957): V15-17 were labelled as IV-37, I-34 and I-6 by Sandage & Walker (1955) V18 and non-variable status of V5, 9 and 15 Arellano Ferro et al. (2004) with ID chart for V18 V19 and non-variable status of V5, 9 and 15 Stetson et al. (2005) with RA, Dec and ID chart for V19 V20 Arellano Ferro et al. (2018) with RA, dec and ID chart V20 was announced in a Note Added in Proof for their Rev. Mex. A&A paper. It was not mentioned in the arXiv preprint which they posted earlier. Arellano Ferro (2020 - private communication) provided the RA and dec listed in the above table. The values published in their 2018 paper were incorrect. V21-47 Lata et al. (2019) with RA, dec and ID charts They also announced a new variable they labelled as V20, but it was clearly not a cluster member. Since Arellano Ferro et al. (2018) had previously announced a different star as V20, the star Arellano Ferro variable is listed as V20 in the above table. (See note on V20.) ======================================================================== References Arellano Ferro, A., Arevalo, M. J., Lazaro, C., Rey, M., Bramich, D. M., Giridhar, S. 2004, Rev. Mex. A&A, 40, 209 Arellano Ferro, A., Rojas Galindo, F. C., Muneer, S., Giridhar, S. 2018, Rev. Mex. A&A, 54, 325 (=arXiv:1803.05313) Baade, W. 1930, A.N., 239, 353 Bellazzini, M., Ibata, R., Malhan, K., Martin, N., Famaey, B., Thomas, G. 2020, A&A, 636, A107 Davis, H. 1917, PASP, 29, 260 Lata, S., Pandey, A. K., Pandey, J. C., Yadav, R. K. S., Pandey, S. B., Gupta, A., Bangia, T. and 16 co-authors, 2019, AJ, 158, 51 Newburn, R. L. 1957, AJ, 62, 197 Riley, A. H., Strigari, L. E. 2020, MNRAS, 494, 983 Sandage, A. R. & Walker, M. F. 1955, AJ, 60, 230 Sohn, S. T., Watkins, L. L., Fardal, M. A., van der Marel, R. P., Deason, A. J., Besla, G., Bellini, A. 2018, ApJ, 862, 52 Stetson, P. B., Catelan, M., Smith, H. A. 2005, PASP, 117, 1325 ==================================