NGC 6440 / C1746-203 (Updated January 2015) RA: 17:48:52.67 DEC: -20:21:34.5 (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 ========================================================================= No known variables ======================================================================= Supplementary Notes NGC 6440 is a heavily reddened metal rich cluster near the Galactic centre. According to the 2010 update to the Harris (1996) catalogue, it has [Fe/H] = -0.36 and a CM diagram by Piotto et al. (2002) based on BV HST observations shows a prominent red HB. The CMD does not extend as faint as the main sequence turnoff and has too much scatter to make it possible to discern a blue straggler sequence. Using Chandra observations, Pooley et al. (2002) found 24 X-ray sources within the cluster half-mass radius and these have been discussed in subsequent papers. Some of them may be LMXBs and others are probably cataclysmic variables. According to Paulo Freire's website, there are 6 millisecond pulsars in NGC 6440. (www.naic.edu/~pfreire/GCpsr.html) ==================================================================== References Harris, W. E. 1996, AJ, 112, 1487 Piotto, G., King, I. R., Djorgovski, S. G., Sosin, C., Zoccali, M., Saviane, I., De Angeli, F. and 5 coauthors, 2002, A&A, 391, 945 Pooley, D., Lewin, W. H. G., Verbunt, F., Homer, L., Margon, B., Gaensler, B. M., Kaspi, V. and 3 coauthors, 2002, ApJ, 573, 184 ======================================================================