Browsing by Author "Rizzi, L."

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    A large and homogeneous sample of SX Phe stars in the Fornax dwarf spheroidal galaxy .
    (2006) Poretti, E.; Dell'Arciprete, L.; Clementini, G.; Held, E. V.; Greco, C.; Gullieuszik, M.; Maio, M.; Rizzi, L.; Catelan , Marcio; Smith, H. A.; Pritzl, B.; De Lee, N.; Rest, A.
    We report on the detection of sixty-one SX Phe stars in the Fornax dwarf spheroidal galaxy using the Wide-Field Imager at the 2.2m ESO-MPI telescope. In spite of their extreme faintness (22.0...
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    The Fornax Project
    (2006) Clementini, G.; Greco, C.; Held, E. V.; Poretti, E.; Catelan, Marcio; Dell'Arciprete, L.; Gullieuszik, M.; Maio, M.; Rizzi, L.; Smith, H. A.; Pritzl, B. J.; Rest, A.; De Lee, N.
    The Fornax Project aims at mapping the classical instability strip of the Fornax dwarf spheroidal galaxy, from the faint Dwarf Cepheids (V ∼ 24-25 mag) to the bright Anomalous Cepheids (V ∼ 19 mag). To achieve this goal, deep B,V time-series photometry of the galaxy has been obtained with the Wide Field Imagers (WFIs) of the ESO 2.2 m and CTIO 4 m telescopes, and the Clay camera at the Magellan 6.5 m telescope. Preliminary results are presented on the Oosterhoff classification of the RR Lyrae stars identified in a northern portion of Fornax field and in three of its globular clusters....
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    Variable stars in Fornax dwarf spheroidal galaxy
    (2005) Greco, C.; Clementini, G.; Held, E. V.; Poretti, E.; Catelan, Marcio; Dell'Arciprete, L.; Gullieuszik, M.; Maio, M.; Rizzi, L.; Smith, H. A.; Pritzl, B. J.; Rest, A.; De Lee, N.
    We present the first results of a variable star search in the field and in the globular clusters of the Fornax dwarf spheroidal galaxy. Variable stars were identified using the Image Subtraction Technique (Alard 2000) on time-series data obtained with the ESO 2.2 m and the Magellan 6.5 m telescopes. The variable star sample includes RR Lyrae stars, Dwarf Cepheids and Anomalous Cepheids. The pulsation properties (namely: periods, light curves, period-amplitude relations and classification in Oosterhoff types) of Fornax variables from the present study are discussed in some detail....
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    Variable Stars in the Globular Clusters and in the Field of the Fornax dSph Galaxy
    (2009) Greco, C.; Clementini, G.; Held, E. V.; Poretti, E.; Catelan, Marcio; Dell'Arciprete, L.; Gullieuszik, M.; Maio, M.; Rizzi, L.; Smith, H. A.; Pritzl, B. J.; Rest, A.; de Lee, N.
    Variable stars have been identified for the first time in Fornax 4, the globular cluster located near the center of the Fornax dwarf spheroidal galaxy. By applying the image-subtraction technique to B and V time series photometry obtained with the MagIC camera of the 6.5 m Magellan Clay telescope and with the wide field imager of the 4 m Blanco CTIO telescope, we detected 27 RR Lyrae stars (22 fundamental-mode, 3 first-overtone, and 2 double-mode pulsators) in a 2.4'×2.4' area centered on Fornax 4. The average and minimum periods of the ab-type RR Lyrae stars, =0.594 days and Pab,min=0.5191 days, respectively, as well as the revised position of the cluster in the horizontal branch type-metallicity plane, all consistently point to an Oosterhoff-intermediate status for the cluster, unlike what is seen for the vast majority of Galactic globular clusters, but in agreement with previous indications for the other globular clusters in Fornax. The average apparent magnitude of the RR Lyrae stars located within 30" from the cluster center is =21.43+/-0.03 mag (σ=0.10 mag, average of 12 stars), leading to a true distance modulus of μ0=20.64+/-0.09 mag or μ0=20.53+/-0.09 mag, depending on whether a low ([Fe/H]=-2.0) or a moderately high ([Fe/H]=-1.5) metallicity is adopted.