We have obtained deep images in the near-infrared J and K filters of four fields in the Sculptor Group spiral galaxy NGC 55 with the ESO VLT and ISAAC camera .
For 40 long-period Cepheid variables in these fields which were recently discovered by Pietrzyński et al. , we have determined mean J and K magnitudes from observations at two epochs , and derived distance moduli from the observed PL relations in these bands .
Using these values together with the previously measured distance moduli in the optical V and I bands , we have determined a total mean reddening of the NGC 55 Cepheids of E ( B-V ) =0.127 \pm 0.019 mag , which is mostly produced inside NGC 55 itself .
For the true distance modulus of the galaxy , our multiwavelength analysis yields a value of 26.434 \pm 0.037 mag ( random error ) , corresponding to a distance of 1.94 \pm 0.03 Mpc .
This value is tied to an adopted true LMC distance modulus of 18.50 mag .
The systematic uncertainty of our derived Cepheid distance to NGC 55 ( apart from the uncertainty on the adopted LMC distance ) is \pm 4 % , with the main contribution likely to come from the effect of blending of some of the Cepheids with unresolved companion stars .
The distance of NGC 55 derived from our multiwavelength Cepheid analysis agrees within the errors with the distance of NGC 300 , strengthening the case for a physical association of these two Sculptor Group galaxies .