The Araucaria Project. The Distance of the Large Magellanic Cloud from Near-Infrared Photometry of RR Lyrae Variables

TL;DR

This study uses near-infrared observations of RR Lyrae stars in the Large Magellanic Cloud to accurately determine its distance, confirming previous measurements with high precision.

Contribution

It provides a new, precise distance measurement to the LMC using deep infrared photometry and multiple calibration methods for RR Lyrae stars.

Findings

Distance modulus of 18.58 mag with small uncertainties

Consistent results across different calibration methods

Agreement with previous independent distance estimates

Abstract

We have obtained deep infrared $J$ and $K$ band observations of five fields located in the Large Magellanic Cloud (LMC) bar with the ESO New Technology Telescope equipped with the SOFI infrared camera. In our fields, 65 RR Lyrae stars catalogued by the OGLE collaboration were identified. Using different theoretical and empirical calibrations of the period-luminosity-metallicity relation, we find consistent LMC distance moduli values. Since the observed fields are situated very close to the center of the LMC, the correction for the tilt of the LMC bar with respect to the line of sight is negligible. Our adopted best true distance modulus to the LMC of $18.58 \pm 0.03$ (statistical) $\pm$ 0.11 (systematic) mag agrees very well with most independent determinations to this galaxy.