Palomar 6 / C1740-262 (Updated May 2014) RA: 17:43:42.2 DEC: -26:13:21 (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 VI photometry by Ortolani et al. (1995) and JHK photometry by Lee & Carney (2002) show the clear presence of a red horizontal branch. The photometry does not extend deep enough to establish the existence of a blue straggler sequence. The metal abundance of Pal 6 is uncertain because the cluster lies in a crowded metal rich star field near the Galactic Centre and field contamination is a problem. The best estimates are based on infrared spectroscopy of its brightest stars. Stephens & Frogel (2004) derived [Fe/H]=-0.52 +/- 0.11 from medium resolution K-band spectroscopy of 5 stars. Lee et al. (2004) derived [Fe/H]=-1.0 +/- 0.1 from 3 stars based on high resolution infrared echelle spectroscopy. They derived radial velocities to ensure that the stars in their sample were cluster members. Terzan (1966) discovered 28 variables in the field around the cluster. He informed Sawyer Hogg (1973) that none is a probable cluster member. Sloan et al. (2010) announced a Mira variable with P=566 days at RA =17:43:49.48, dec = -26:15:27.9 (2000), a distance of 2.67 arcmin from the cluster centre, well within the tidal radius, which is 8.3 arcmin according to the 2010 update to the Harris (1996) catalogue. However, based on its observed K magnitude and circumstellar extinction, they concluded that the Mira variable must be a foreground object and not a cluster member. Lynch & Ransom (2011) conducted a search for pulsars, but did not find any in Palomar 6. ===================================================================== References Lee, J.-W. & Carney, B. W. 2002, AJ, 123, 3305 Lee, J.-W., Carney, B. W., Balachandran, S. C. 2004, AJ, 128, 2388 Lynch, R. S. & Ransom, S. M. 2011, ApJ, 730, L11 Ortolani, S., Bica, E., Barbuy, B. 1995, A&A, 296, 680 Sawyer Hogg, H. 1973, Publ. DDO, 3, No. 6 Sloan, G. C., Matsunaga, N., Matsuura, M., Zijlstra, A. A., Kraemer, K. E., Wood, P. R., Nieusma, J., Bernard-Salas, J., Devost, D., Houck, J. R. 2010, ApJ, 719, 1274 Stephens, A. W. & Frogel, J. A. 2004, AJ, 127, 925 Terzan, A. 1966, Haute Provence Publ., 9, 1 =======================================================================