THE ASTRONOMICAL JOURNAL      VOLUME 105, NUMBER 2, PAGE 527      FEBRUARY 1993

 THE LARGE MAGELLANIC CLOUD CLUSTER NGC 1835: PHOTOMETRY OF THE RR LYRAE STARS

                              ALISTAIR R. WALKER

      Cerro Tololo Inter-American Observatory, National Optical Astronomy
                 Observatories, Casilla 603, La Serena, Chile


                                   ABSTRACT

    Photometry is presented for the RR Lyrae variables in the Large
    Magellanic Cloud (LMC) cluster NGC 1835.  Sixteen new variables have
    been discovered.  Due to the extreme crowding of the LMC field stars,
    the scatter of the light curves and mean magnitudes is greater than
    that found for other LMC clusters studied under similar conditions.
    The derived parameters of the light curves yield E(B-V) = 0.13 and
    [Fe/H] = -1.8, consistent with previous measurements. The complete
    sample of RR Lyraes has mean magnitudes <V> = 19.38, <B> = 19.70. If a
    distance modulus of 18.5 mag for the LMC is assumed, then in the mean
    the NGC 1835 RR Lyraes have <Mv> = 0.48, almost identical to the
    average found by the same procedure for the six other LMC clusters.