<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Hatzidimitriou, D.</style></author><author><style face="normal" font="default" size="100%">Papadakis, I.</style></author><author><style face="normal" font="default" size="100%">Croke, B. F. W.</style></author><author><style face="normal" font="default" size="100%">Papamastorakis, I.</style></author><author><style face="normal" font="default" size="100%">Paleologou, E. V.</style></author><author><style face="normal" font="default" size="100%">Xanthopoulos, E.</style></author><author><style face="normal" font="default" size="100%">Haerendel, G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The Age of NGC 6426, a Metal-poor Globular Cluster in the Galactic Halo</style></title><short-title><style face="normal" font="default" size="100%">The Astronomical Journal</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">GALAXY: GLOBULAR CLUSTERS: INDIVIDUAL: NGC NUMBER: NGC 6426</style></keyword><keyword><style  face="normal" font="default" size="100%">GALAXY: HALO</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year><pub-dates><date><style  face="normal" font="default" size="100%">1999/06/1</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://ui.adsabs.harvard.edu/abs/1999AJ....117.3059H</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">117</style></volume><pages><style face="normal" font="default" size="100%">3059 - 3065</style></pages><isbn><style face="normal" font="default" size="100%">0004-6256</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">We present B, V, R, and I photometry of the metal-poor globular cluster in the galactic halo, NGC 6426. The observations were performed using the 1.3 m Telescope at Skinakas Observatory in Crete. We derived the reddening of the cluster to be E(B-V)=0.39+/-0.02 [E(V-I)=0.53+/-0.03]. The metal abundance of the cluster was estimated from the shape of the red giant branch following the techniques by Sarajedini and by Da Costa &amp;amp; Armandroff. It was found to be [Fe/H]=-2.33+/-0.15 dex. The mean V magnitude of the RR Lyrae variables found in the cluster is 18.14+/-0.02 (based on a paper in preparation). The resulting distance modulus of the cluster is 16.41+/-0.07. Finally, we derived the relative age of NGC 6426. Using the methodology of Harris et al., we found that NGC 6426 is marginally older than M92 (by ~=0.7 Gyr). Following the Chaboyer, Demarque, &amp;amp; Sarajedini method we found NGC 6426 to have the same age as the mean metal-poor globular cluster of the galactic halo.</style></abstract></record></records></xml>