Browsing by Author "Altmann, M."

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    A Search for EHB Pulsators in the Globular Cluster NGC 6752
    (2007) Catelan , Marcio; Prieto, G. E.; Zoccali, M.; Weidner, C.; Stetson, P. B.; Moni Bidin, C.; Altmann, M.; Smith, H. A.; Pritzl, B. J.; Borissova, J.; de Medeiros, J. R.
    We describe the status of a project whose main goal is to detect variability along the extreme horizontal branch of the globular cluster NGC 6752. Based on Magellan 6.5-m data, preliminary light curves are presented for some candidate variables. By combining our time-series data, we also produce a deep CMD of unprecedented quality for the cluster which reveals a remarkable lack of main sequence binaries, possibly pointing to a low primordial binary fraction....
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    Meet the COG's
    (2008) Altmann, M.; Catelan, Márcio; Zoccali, M.
    Kinematics combined with detailed element abundances provide a method of analysis of stellar populations that uses as much available information as possible, in contrast to other methods. Here we employ this technique on local A-type horizontal branch stars in an ongoing programme to search for ω Centauri debris among these objects. This led us to discover another group of stars with very similar kinematics and abundances, the Cometary Orbit Group (COG). We also comment on the future of this kind of undertaking in the Gaia era....
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