NGC 5053 / C1313+179 (Updated January 2012) RA: 13:16:27.09 DEC: +17:42:00.9 (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 13:15:59.33 +17:44:27.5 R0 0.6472 16.573 1.05 V RR0 2 13:16:12.37 +17:41:46.6 R0 0.3790 16.639 0.49 V RR1 3 13:16:35.62 +17:44:15.9 R0 0.5929 16.617 0.69 V RR0 4 13:16:28.03 +17:39:55.2 R0 0.6671 16.541 1.05 V RR0 5 13:16:41.22 +17:38:10.7 R0 0.7149 16.588 0.60 V RR0 6 13:16:34.62 +17:43:07.2 R0 0.2922 16.700 0.56 V RR1 7 13:16:19.71 +17:44:38.3 R0 0.3519 16.553 0.47 V RR1 8 13:16:34.03 +17:42:40.3 R0 0.3628 16.659 0.58 V RR1 9 13:16:11.89 +17:48:10.8 R0 0.7402 16.606 0.50 V RR0 10 13:16:32.53 +17:42:46.4 R0 0.7759 16.525 0.24 V RR0 11 13:16:32.24 +17:42:09.8 R0 0.0368 19.30 0.14 V SXPHE Note 12 13:16:25.31 +17:43:48.3 R0 0.0350 19.50 0.20 V SXPHE Note 13 13:16:23.85 +17:42:01.1 R0 0.0342 19.46 0.13 V SXPHE 14 13:16:17.85 +17:40:52.7 R0 0.0393 19.41 0.08 V SXPHE 15 13:16:17.21 +17:40:29.5 R0 0.0356 19.53 0.12 V SXPHE ============================================================== Supplementary Notes The RA and dec for V1-15 are from Samus et al. (2009). The periods, magnitudes, amplitudes and classifications for V1 to V10 are from Nemec (2004) and for V11-15 are from Nemec et al. (1995). According to Law & Majewski (2010), NGC 5053 might be associated with the Sgr dwarf galaxy, but this can not be conclusively determined until its proper motion is measured. =========================================================== Notes on individual stars V11: The star listed as V11 in the above table is blue straggler #7 of Nemec & Cohen (1989) and called NC7 by Nemec et al. (1995). The star listed as V11 in Sawyer Hogg's 3rd (1973) catalogue is a different star. It is Baade's (1928) comparision star c which Perova (1962) indicated as a possible variable. The number V11 was assigned by Sawyer Hogg (1973). However, Baryshnikova et al. (1989) pointed out that this star lies on the giant branch and is unlikley to be variable because Samus examined Perova's material and did not confirm its variability. V12: Nemec et al. (1995) indicated that the V amplitude of this star varies from 0.15 to 0.25 mag. The V amplitudes that they listed for the SX PHe variables in Table 17 of their paper were (Vmin-Vmax) - see page 1210 ============================================== Discovery of the variable stars in NGC 5053: V1-9: Baade (1928) with x,y coordinates and an ID chart V10: Sawyer (1946) with x,y coordinates. An ID chart for V1-V10 was later published by Rosino (1949) and also by Sandage et al. (1977) V11-14 (= Blue stragglers # 7, 11, 13, 14) Nemec & Cohen (1989) - see footnote on page 796 - with X,Y pixel positions (Table 6) and finding charts (Figure 1a for #7, 11, 13 and 1c for #14). In their study of these variables, Nemec et al (1995) referred to them as NC7, NC11, NC13, NC14. The numbers V11-14 were assigned in our electronic catalogue in 2001. V15 (= NC15) Nemec et al. (1995) This star is blue straggler #15 of Nemec & Cohen (1989) who published its X,Y pixel position (see Table 6) and ID chart (see Figure 1c) The number V15 was assigned in our electronic catalogue in 2001. ------------------------- Probable variable stars Blue stragglers: BS4, BS5, BS19, BS25, BS28, BS29, BS30 are all candidate SX Phe variables according to Arellano Ferro et al. (2010) - see their discussion of blue stragglers in section 5.3, search for new variables in section 6 and ID chart in Figure 15. RGB star: NV1 Arellano Ferro et al. (2010) with ID chart in Figure 15, light curve in Figure 12 and discussion in section 6.3 ----------------------- Suspected variable stars Blue stragglers: BS22, BS23, BS31 Arellano Ferro et al. (2010) - see section 6.1.2 ======================================================================= References Arellano Ferro, A., Giridhar, S., Bramich, D. M. 2010, MNRAS, 402, 226 Baade, W. 1928, A.N., 232, 193 = Hamburg Mitt., 6, no. 29, 92 Baryshnikova, O. A., Samus, N. N., Sil'chenko, N. N. 1989, Sov. Ast, 33, 397 = A Zh, 66, 767 Law, D. R. & Majewski, S. R. 2010, ApJ, 718, 1128 Nemec, J. M. 2004, AJ, 127, 2185 Nemec, J. M., Mateo, M., Burke, M., Olszewski, E. W. 1995, AJ, 110, 1186 Nemec, J. M. & Cohen, J. G. 1989, ApJ, 336, 780 Perova, N. B. 1962, Per. Zvez., 14, 255 Rosino, L. 1949, Mem. S. A. I. 20, 227 = Bologna Publ. V, No. 10 Sandage, A., Katem, B., Johnson, H. L., 1977, AJ, 82, 389 Sawyer, H. B. 1946, DDO Publ., 1, no. 18 ========================================================================