EDP Sciences
Free access
Volume 420, Number 2, June III 2004
Page(s) 625 - 629
Section Stellar structure and evolution
DOI http://dx.doi.org/10.1051/0004-6361:20040981

A&A 420, 625-629 (2004)
DOI: 10.1051/0004-6361:20040981

The bottleneck of CNO burning and the age of Globular Clusters

G. Imbriani1, 2, 3, H. Costantini4, A. Formicola5, 6, D. Bemmerer7, R. Bonetti8, C. Broggini9, P. Corvisiero4, J. Cruz10, Z. Fülöp11, G. Gervino12, A. Guglielmetti8, C. Gustavino6, G. Gyürky11, A. P. Jesus10, M. Junker6, A. Lemut4, R. Menegazzo9, P. Prati4, V. Roca2, 3, C. Rolfs5, M. Romano2, 3, C. Rossi Alvarez9, F. Schümann5, E. Somorjai11, O. Straniero1, 2, F. Strieder5, F. Terrasi2, 13, H. P. Trautvetter5, A. Vomiero14 and S. Zavatarelli4

1  INAF-Osservatorio Astronomico di Collurania, Italy
2  INFN-sezione di Napoli, Complesso Universitario di Monte Sant'Angelo, Via Cintia, ed. G80126 Napoli, Italy
3  Dipartimento di Scienze Fisiche, Universitá Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cintia, ed. G80126 Napoli, Italy
4  Universitá di Genova, Dipartimento di Fisica and INFN, Genova, Italy
5  Ruhr Universität Bochum, Bochum, Germany
6  INFN Laboratori Nazionali del Gran Sasso, Assergi, Italy
7  Institut für Atomare Physik und Fachdidaktik, Technische Universität Berlin
8  Universitá di Milano, Istituto di Fisica Generale Applicata and INFN, Milano, Italy
9  INFN-sezione di Padova, Italy
10  Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa, Portugal
11  Atomki, Debrecen, Hungary
12  Universitá di Torino, Dipartimento di Fisica Sperimentale and INFN, Torino, Italy
13  Seconda Universitá di Napoli, Dipartimento di Scienze Ambientali, Caserta, and INFN, Napoli, Italy
14  Universitá di Padova, Dipartimento di Fisica, Padova and INFN Legnaro, Italy

(Received 6 January 2004 / Accepted 1 March 2004 )

The transition between the Main Sequence and the Red Giant Branch in low mass stars is powered by the onset of CNO burning, whose bottleneck is 14N(p,  $\gamma)^{15}$O. The LUNA collaboration has recently improved the low energy measurements of the cross section of this key reaction. We analyse the impact of the revised reaction rate on the estimate of the Globular Cluster ages, as derived from the turnoff luminosity. We found that the age of the oldest Globular Clusters should be increased by about 0.7-1 Gyr with respect to the current estimates.

Key words: stars: evolution -- stars: population II -- nuclear reactions, nucleosynthesis, abundances -- Galaxy: globular clusters: general -- Galaxy: formation -- cosmology: distance scale

Offprint request: G. Imbriani, imbriani@na.infn.it

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