Browsing by Author "HILKER, M"

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    METALLICITIES IN THE MAGELLANIC CLOUDS FROM CCD STROMGREN PHOTOMETRY - THE GLOBULAR-CLUSTERS NGC-1866 (LMC) AND NGC-330 (SMC)
    (1995) HILKER, M; RICHTLER, T; GIEREN, W
    We present Stromgren CCD photometry for the globular clusters NGC 1866 and NGC 330 in the LMC/SMC and for their neighbouring field population. The metallicities, which result from the Stromgren data for NGC 1866 and NGC 330 are - 0.43 +/- 0.18 dex and -0.93 +/- 0.16 dex, respectively. The metallicity of NGC 1866 could be lower by 0.2 dex, if NGC 330 has an abundance of -1.1 dex, as it is indicated by spectroscopic studies. This is the first direct determination of the metallicity of NGC 1866, a key object in stellar evolution theory.
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    THE DISTANCE TO THE LARGE MAGELLANIC CLOUD CLUSTER NGC 1866 FROM ITS CEPHEID MEMBERS
    (1994) GIEREN, WP; RICHTLER, T; HILKER, M
    We have derived distances to four Cepheid variables of similar periods (2.6-3.5 days) in the field of the young LMC cluster NGC 1866 using the visual surface brightness modification of the Baade-Wesselink method. For three of these variables, consistent distances are obtained which support their cluster membership and yield a true cluster distance modulus of 18.47 +/- 0.20 mag. The distances have been corrected for the nonsolar metallicity of -0.6 dex recently determined for NGC 1866 by Hilker et al. A fourth Cepheid, HV 12204, is shown to have a bright blue companion star which invalidates the Baade-Wesselink analysis; this Cepheid is likely to be a cluster member in a spectroscopic binary system.