Zobrazeno 1 - 10
of 343
pro vyhledávání: '"Nordstrom, B."'
The detailed chemical composition of most metal-poor halo stars has been found to be highly uniform, but a minority of stars exhibit dramatic enhancements in their abundances of heavy neutron-capture elements and/or of carbon. The key question for Ga
Externí odkaz:
http://arxiv.org/abs/1509.05344
Autor:
Torres, G., Clausen, J. V., Bruntt, H., Claret, A., Andersen, J., Nordstrom, B., Stefanik, R. P., Latham, D. W.
CONTEXT: Accurate physical properties of eclipsing stars provide important constraints on models of stellar structure and evolution, especially when combined with spectroscopic information on their chemical composition. Empirical calibrations of the
Externí odkaz:
http://arxiv.org/abs/1112.3974
Autor:
Spite, Monique, Caffau, E., Andrievsky, S. M., Korotin, S. A., Depagne, E., Spite, F., Bonifacio, P., Ludwig, H. -G., Cayrel, R., Francois, P., Hill, V., Plez, B., Andersen, J., Barbuy, B., Beers, T. C., Molaro, P., Nordstrom, B., Primas, F.
Sulfur is important: the site of its formation is uncertain, and at very low metallicity the trend of [S/Fe] against [Fe/H] is controversial. Below [Fe/H]=-2.0, [S/Fe] remains constant or it decreases with [Fe/H], depending on the author and the mult
Externí odkaz:
http://arxiv.org/abs/1012.4358
The influence of stellar activity on the fundamental properties of stars around and below 1 Msun is not well understood. We aim to determine absolute dimensions and abundances for the solar-type detached eclipsing binary V636 Cen. The results are bas
Externí odkaz:
http://arxiv.org/abs/0905.3077
Autor:
Bonifacio, P., Spite, M., Cayrel, R., Hill, V., Spite, F., Francois, P., Plez, B., Ludwig, H. -G, Caffau, E., Molaro, P., Depagne, E., Andersen, J., Barbuy, B., Beers, T. C., Nordstrom, B., Primas, F.
CONTEXT:The detailed chemical abundances of extremely metal-poor (EMP) stars are key guides to understanding the early chemical evolution of the Galaxy. Most existing data are, however, for giant stars which may have experienced internal mixing later
Externí odkaz:
http://arxiv.org/abs/0903.4174
Autor:
Bonifacio, P., Andersen, J., Andrievsky, S., Barbuy, B., Beers, T. C., Caffau, E., Cayrel, R., Depagne, E., Francois, P., Hernandez, J. I. Gonzalez, Hansen, C. J., Herwig, F., Hill, V., Korotin, S. A., Ludwig, H. -G., Molaro, P., Nordstrom, B., Plez, B., Primas, F., Sivarani, T., Spite, F., Spite, M.
In ESO period 65 (April-September 2000) the large programme 165.N-0276, led by Roger Cayrel, began making use of UVES at the Kueyen VLT telescope. Known within the Team and outside as ``First Stars'', it was aimed at obtaining high resolution, high s
Externí odkaz:
http://arxiv.org/abs/0801.1293
Ages, metallicities, space velocities, and Galactic orbits of stars in the Solar neighbourhood are fundamental observational constraints on models of galactic disk evolution. We aim to consolidate the calibrations of uvby photometry into Te, [Fe/H],
Externí odkaz:
http://arxiv.org/abs/0707.1891
Autor:
Bonifacio, P., Molaro, P., Sivarani, T., Cayrel, R., Spite, M., Spite, F., Plez, B., Andersen, J., Barbuy, B., Beers, T. C., Depagne, E., Hill, V., Francois, P., Nordstrom, B., Primas, F.
Aims. This study aims to determine the level and constancy of the Spite plateau as definitively as possible from homogeneous high-quality VLT-UVES spectra of 19 of the most metal-poor dwarf stars known. Methods. Our high-resolution (R ~ 43000), high
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610245
Autor:
Sivarani, T., Beers, T. C., Bonifacio, P., Molaro, P., Cayrel, R., Herwig, F., Spite, M., Spite, F., Plez, B., Andersen, J., Barbuy, B., Depagne, E., Hill, V., Francois, P., Nordstrom, B., Primas, F.
From high-resolution VLT/UVES spectra (R~43,000), we determine abundances or upper limits for Li, C, N, O, and other important elements, as well as 12C/13C isotopic ratio for three Carbon enhanced metal poor stars. All three stars have -3.30 <= [Fe/H
Externí odkaz:
http://arxiv.org/abs/astro-ph/0608112
Publikováno v:
Mon.Not.Roy.Astron.Soc. 365 (2006) 1309-1323
We search for signatures of past accretion events in the Milky Way in the recently published catalogue by Nordstrom et al.(2004), containing accurate spatial and kinematic information as well as metallicities for 13240 nearby stars. To optimize our s
Externí odkaz:
http://arxiv.org/abs/astro-ph/0505401