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The stellar activity-rotation relationship revisited: Dependence of saturated and non-saturated X-ray emission regimes on stellar mass for late-type dwarfs ?
We present the results of a new study on the relationship between coronal X-ray emission and stellar rotation in late-type main-sequence stars. We have selected a sample of 259 dwarfs in the B VExpand
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The CFHT Open Star Cluster Survey. II. Deep CCD Photometry of the Old Open Star Cluster NGC 6819
We present analysis of deep CCD photometry for the very rich, old open star cluster NGC 6819. The science goals are to catalog the white dwarfs in the cluster and measure the cluster luminosity andExpand
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The White Dwarf Cooling Age of the Rich Open Star Cluster NGC 2099 (M37)
We present deep CCD photometry of the very rich, intermediate-age (similar to the Hyades) open star cluster NGC 2099 (M37). The V, B-V color-magnitude diagram (CMD) for the cluster shows an extremelyExpand
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The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. III. A Quintuple Stellar Population in NGC 2808
In this study we present the first results from multi-wavelength Hubble Space Telescope (HST) observations of the Galactic globular cluster (GC) NGC 2808 as an extension of the Hubble Space TelescopeExpand
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Theoretical amplitudes and lifetimes of non-radial solar-like oscillations in red giants
Context. Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internalExpand
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NGC 2419: a large and extreme second generation in a currently undisturbed cluster
We analyse complementary Hubble Space Telescope and Subaru data for the globular cluster NGC 2419. We make a detailed analysis of the horizontal branch (HB), which is composed of two main groups ofExpand
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The helium spread in the globular cluster 47 Tuc
Spectroscopy has shown the presence of CN band dichotomy and Na–O anticorrelations for 50–70 per cent of the investigated samples in the cluster 47 Tuc, otherwise considered a ‘normal’ prototype ofExpand
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Dust formation around AGB and SAGB stars: a trend with metallicity?
We calculate the dust formed around asymptotic giant branch (AGB) and super-AGB stars of metallicity Z = 0.008 by following the evolution of models with masses in the range 1 M⊙ ≤ M ≤ 8 M⊙ throughExpand
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Yields from low metallicity, intermediate mass AGB stars:. Their role for the CNO and lithium abundances in Globular Cluster stars
We present the results of extensive computation of the Thermal Pulse phase AGB evolution of stars of metallicities in mass fraction 2 10 4 Z 0:01, for those masses in the range 2:5 M=M 6, which suerExpand
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The star cluster Collinder 232 in the Carina complex and its relation to Trumpler 14/16 ,
In this paper we present and analyze new CCD UBVRI photometry down to $V\approx21$ in the region of the young open cluster Collinder 232, located in the Carina spiral arm, and discuss itsExpand
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