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Extra-Mixing in Luminous Cool Red Giants: Hints from Evolved Stars With and Without Li

Published online by Cambridge University Press:  05 March 2013

R. Guandalini ,
S. Palmerini ,
M. Busso  and
S. Uttenthaler
R. Guandalini*
Affiliation:
Dipartimento di Fisica, Università degli Studi di Perugia, via Pascoli, 06123 Perugia, Italy INFN Sezione di Perugia, via Pascoli, 06123 Perugia, Italy
S. Palmerini
Affiliation:
Dipartimento di Fisica, Università degli Studi di Perugia, via Pascoli, 06123 Perugia, Italy INFN Sezione di Perugia, via Pascoli, 06123 Perugia, Italy
M. Busso
Affiliation:
Dipartimento di Fisica, Università degli Studi di Perugia, via Pascoli, 06123 Perugia, Italy INFN Sezione di Perugia, via Pascoli, 06123 Perugia, Italy
S. Uttenthaler
Affiliation:
Instituut voor Sterrenkunde, K. U. Leuven, Celestijnenlaan 200D, 3000 Leuven, Belgium
*
D Corresponding author. Email: guandalini@fisica.unipg.it
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Abstract

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We present an analysis of Li abundances in low mass stars (LMS) during the Red Giant Branch (RGB) and Asymptotic Giant Branch (AGB) stages, based on a new determination of their luminosities and evolutionary status. By applying recently suggested models for extra-mixing, induced by magnetic buoyancy, we show that both Li-rich and Li-poor stars can be accounted for. The simplest scenario implies the development of fast instabilities on the RGB, where Li is produced. When the fields increase in strength, buoyancy slows down and Li is destroyed. 3He is consumed, at variable rates. The process continues on the AGB, where however moderate mass circulation rates have little effect on Li due to the short time available. O-rich and C-rich stars show different histories of Li production/destruction, possibly indicative of different masses. More complex transport schemes are allowed by magnetic buoyancy, with larger effects on Li, but most normal LMS seem to show only the range of Li variation discussed here.

Keywords

nuclear reactions, nucleosynthesis, abundancesstars: AGBstars: evolutionstars: red giants

Information

Type
Theory, Evolution and Models
Information
Publications of the Astronomical Society of Australia , Volume 26 , Issue 3 , 2009 , pp. 168 - 175
Copyright
Copyright © Astronomical Society of Australia 2009

References

Abia, C. & Isern, J., 2000, ApJ, 536, 438 CrossRefGoogle Scholar
Andrews, A. D. et al., 1988, A&A, 204, 177 Google Scholar
Bergeat, J. & Chevallier, L., 2005, A&A, 429, 235 Google Scholar
Boffin, H. M. J., Abia, C., Isern, J. & Rebolo, R., 1993, A&AS, 102, 361 Google Scholar
Brown, J. A., Sneden, C., Lambert, D. L. & Dutchover, E. Jr., 1989, ApJS, 71, 293 CrossRefGoogle Scholar
Busso, M. Wasserburg, G. J., Nollett, K. M. & Calandra, A., 2007a, ApJ, 671, 802 CrossRefGoogle Scholar
Busso, M., Guandalini, R., Persi, P., Corcione, L. & Ferrari-Toniolo, M., 2007b, AJ, 133, 2310 CrossRefGoogle Scholar
Cameron, A. G. W. & Fowler, W. A., 1971, ApJ, 164, 111 CrossRefGoogle Scholar
Castilho, B. V., 2000, IAUS, 198, 331 Google Scholar
Charbonnel, C., 1994, A&A, 282, 811 Google Scholar
Charbonnel, C. & Do Nascimento, J. D. Jr., 1998, A&A, 336, 915 Google Scholar
Charbonnel, C. & Balachandran, S. C., 2000, A&A, 359, 563 Google Scholar
Denissenkov, P. A. & VandenBerg, D. A., 2003, ApJ, 593, 509 CrossRefGoogle Scholar
Denissenkov, P. A., Pinsonneault, M. & MacGregor, K. B., 2009, ApJ, 696, 1823 CrossRefGoogle Scholar
Denn, G. R., Luck, R. E. & Lambert, D. L., 1991, ApJ, 377, 657 CrossRefGoogle Scholar
Eggleton, P. P., Dearborn, D. S. P. & Lattanzio, J. C., 2006, Sci, 314, 1580 CrossRefGoogle Scholar
Gilroy, K. K., 1989, ApJ, 347, 835 CrossRefGoogle Scholar
Gilroy, K. K. & Brown, J. A., 1991, ApJ, 371, 578 CrossRefGoogle Scholar
Gratton, R. G., Carretta, E., Matteucci, F. & Sneden, C., 2000, A&A, 358, 671 Google Scholar
Guandalini, R., Busso, M., Ciprini, S., Silvestro, G. & Persi, P., 2006, A&A, 445, 1069 Google Scholar
Guandalini, R. & Busso, M., 2008, A&A, 488, 675 Google Scholar
Guandalini, R., Tosti, G. & Busso, M., 2008, EAS Publications Series, 33, 243 CrossRefGoogle Scholar
Kraft, R. P., 1994, PASP, 106, 553 CrossRefGoogle Scholar
Lambert, D. L., Dominy, J. F. & Sivertsen, S., 1980, ApJ, 235, 114 CrossRefGoogle Scholar
Luck, R. E. & Lambert, D. L., 1982, ApJ, 256, 189 CrossRefGoogle Scholar
Mallik, S. V., 1999, A&A, 352, 495 Google Scholar
Melo, C. H. F., de Laverny, P., Santos, N. C., Israelian, G., Randich, S., Do Nascimento, J. D. Jr. & de Medeiros, J. R., 2005, A&A, 439, 227 Google Scholar
Nordhaus, J., Busso, M., Wasserburg, G. J., Blackman, E. G. & Palmerini, S., 2008, ApJ, 684, L29 CrossRefGoogle Scholar
Palacios, A., Talon, S., Charbonnel, C. & Forestini, M., 2003, A&A, 399, 603 Google Scholar
Palacios, A., Charbonnel, C., Talon, S. & Siess, L., 2006, A&A, 453, 261 Google Scholar
Palmerini, S. & Busso, M., 2008, NewAR, 52, 412 CrossRefGoogle Scholar
Palmerini, S., Busso, M., Maiorca, E. & Guandalini, R., 2009, PASA, this volumeGoogle Scholar
Sackmann, I.-J. & Boothroyd, A. I., 1999, ApJ, 510, 217 CrossRefGoogle Scholar
Smith, V. V. & Lambert, D. L., 1990, ApJS, 72, 387 CrossRefGoogle Scholar
Sweigart, A. V. & Mengel, J. G., 1979, ApJ, 229, 624 CrossRefGoogle Scholar
Takeda, Y., Sato, B., Kambe, E., Izumiura, H., Masuda, S. & Ando, H., 2005, PASJ, 57, 109 CrossRefGoogle Scholar
Uttenthaler, S., Lebzelter, T., Palmerini, S., Busso, M., Aringer, B. & Lederer, M. T., 2007, A&A, 471, L41 Google Scholar
van Leeuwen, F., 2007, ASSL, 350 Google Scholar
Vanture, A. D., Smith, V.V., Lutz, J., Wallerstein, G., Lambert, D. & Gonzalez, G., 2007, PASP, 119, 147 CrossRefGoogle Scholar
Wasserburg, G. J. & Busso, M., 2008, AIPC, 1001, 295 Google Scholar