The distance to the Large Magellanic Cloud cluster Reticulum from the K-band period-luminosity-metallicity relation of RR Lyrae stars

We present new and accurate near-infrared J- and K-s-band data of the Large Magellanic Cloud cluster Reticulum. Data were collected with SOFI at the New Technology Telescope and covered an area of approximately 5' x 5' around the center of the cluster. Current data allowed us to derive accurate mean K-band magnitudes for 21 fundamental (RRab) and 9 first-overtone (RRc) RR Lyrae stars. On the basis of the semiempirical K-band period-luminosity- metallicity (PLZ(K)) relation we have recently derived, we find that the absolute distance to this cluster is 18.52 +/- 0.005 ( random) +/-0.117 ( systematic). Note that the current error budget is dominated by systematic uncertainty affecting the absolute zero-point calibration and the metallicity scale.