On the difference between nuclear and contraction ages

Autor(en)
W. Lyra, A. Moitinho, N. S. van der Bliek, J. Alves
Abstrakt

Context: .Ages derived from low mass stars still contracting onto the main sequence often differ from ages derived from the high mass ones that have already evolved away from it.
Aims: .We investigate the general claim of disagreement between these two independent age determinations by presenting UBVRI photometry for the young galactic open clusters NGC 2232, NGC 2516, NGC 2547 and NGC 4755, spanning the age range ~10-150 Myr
Methods: .We derived reddenings, distances, and nuclear ages by fitting ZAMS and isochrones to color-magnitudes and color-color diagrams. To derive contraction ages, we used four different pre-main sequence models, with an empirically calibrated color-temperature relation to match the Pleiades cluster sequence.
Results: .When exclusively using the V vs. V-I color-magnitude diagram and empirically calibrated isochrones, there is consistency between nuclear and contraction ages for the studied clusters. Although the contraction ages seem systematically underestimated, in none of the cases do they deviate by more than one standard deviation from the nuclear ages.

Organisation(en)
Institut für Astrophysik
Externe Organisation(en)
European Southern Observatory (Germany), Cerro Tololo InterAmerican Observatory (CTIO), Universidade Federal do Rio de Janeiro, Uppsala Astronomical Observatory (UAO), Observatório Astronómico de Lisboa
Journal
Astronomy & Astrophysics
Band
453
Seiten
101-119
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20053894
Publikationsdatum
07-2006
Peer-reviewed
Ja
ÖFOS 2012
103003 Astronomie, 103004 Astrophysik
Schlagwörter
Link zum Portal
https://ucrisportal.univie.ac.at/de/publications/3623d0a3-b00e-48da-9dce-67f6025abc6f