THE DISTANCE MODULUS OF THE LARGE MAGELLANIC CLOUD - CONSTRAINTS FROMRR LYRAE PULSATION PROPERTIES

It has recently been suggested that the discrepancy between the ''long '' and ''short'' distance moduli of the Large Magellanic Cloud (LMC), as inferred from the properties of the Cepheid and RR Lyrae variables, respectively, might be due to the action of ''third parameters'' betw een the Galaxy and the LMC, which would make the RR Lyraes in the old LMC globular clusters brighter than their Galactic counterparts by sim ilar or equal to 0.3 mag. Through analysis of the RR Lyrae pulsation p roperties, we show that this idea is not supported by the available da ta. A satisfactory explanation of the problem has yet to be found.