[en] 12 Boötis is a spectroscopic binary whose visual orbit has been resolved by interferometry. Though the physical parameters of the system have been determined with an excellent precision, the theoretical modelling of the components is still uncertain. We study the capability of solar-like oscillations to distinguish between calibrated models of the system obtained by including in the stellar modelling different mixing processes. We consider different scenarios for the chemical transport processes: classical overshooting, microscopic diffusion and turbulent mixing. For each of them we calibrate the stellar models of 12 Boo A and B by fitting the available observational constraints by means of a Levenberg-Marquardt minimization algorithm and, finally, we analyse the asteroseismic properties of different calibrated models. Several solutions with 12 Boo A in (or close to) post-main-sequence (post-MS) and 12 Boo B on MS are found by assuming a thickness of the overshooting layer between 0.06 and 0.23 the pressure scaleheight. Solutions with both components on the MS can be found only by assuming an overshoot larger in the primary than in the secondary, or a more efficient central mixing for 12 Boo A than for 12 Boo B. We show that the detection of solar-like oscillations expected in these stars would allow us to distinguish between different scenarios and provide therefore an estimation of the overshooting parameters and of the properties of extra-mixing processes.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Miglio, Andrea; Institut d'Astrophysique et de Géophysique de l'Université de Liège, Allée du 6 Août, 17 B-4000 Liège, Belgium
Montalban Iglesias, Josefa ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Astrophysique stellaire théorique et astérosismologie
Maceroni, Carla; INAF-Osservatorio di Roma, via Frascati-33, Monteporzio Catone (RM), Italy)
Language :
English
Title :
12 Boötis: a test-bed for extra-mixing processes in stars
Böhm-Vitense E., 1958, Zeitschrift fur Astrophysics, 46, 108
Balachandran S., 1990, ApJ, 354, 310
Barry D. C., 1970, ApJS, 19, 281
Bedding T. R., Kjeldsen H., Butler R. P., McCarthy C., Marcy G. W., O'Toole S. J., Tinney C. G., Wright J. T., 2004, ApJ, 614, 380
Blackwell D. E., Lynas-Gray A. E., 1994, A&A, 282, 899
Blackwell D. E., Petford A. D., Arribas S., Haddock D. J., Selby M. J., 1990, A&A, 232, 396
Boden A. F., Torres G., Hummel C. A., 2005, ApJ, 627, 464
Bouchy F., Bazot M., Santos N. C., Vauclair S., Sosnowska D., 2005, A&A, 440, 609
Bouchy F., Carrier F., 2002, A&A, 390, 205
Carrier F., Bourban G., 2003, A&A, 406, L23
Caughlan G. R., Fowler W. A., 1988, At. Data Nucl. Data Tables, 40, 283
Chiosi C., 1998, in Aparicio A., Herrero A., Sánchez F., eds, Stellar Astrophysics for the Local Group: VIII Canary Islands Winter School of Astrophysics. Cambridge Univ. Press, Cambridge, p. 1
Christensen-Dalsgaard J., Bedding T. R., Kjeldsen H., 1995, ApJ, 443, L29
Cox J. P., Giuli R. T., 1968, Principles of Stellar Structure. Gordon and Breach, New York
D'Antona F., Cardini D., Di Mauro M. P., Maceroni C., Mazzitelli I., Montalbán J., 2005, MNRAS, 363, 847
De Medeiros J. R., Udry S., 1999, A&A, 346, 532
Di Mauro M. P., Christensen-Dalsgaard J., Paternò L., D'Antona F., 2004, Sol. Phys., 220, 185
Duncan D. K., 1981, ApJ, 248, 651
Formicola A. et al., 2004, Phys. Lett. B, 591, 61
Grevesse N., Noels A., 1993, in Hauck B., Paltani S. R. D., eds, La formation des éléments chimiques. AVCP, Lausanne, p. 205
Holman M. J., Wiegert P. A., 1999, AJ, 117, 621
Houdek G., Balmforth N. J., Christensen-Dalsgaard J., Gough D. O., 1999, A&A, 351, 582
Iben I. J., 1991, ApJS, 76, 55
Iglesias C. A., Rogers F. J., 1996, ApJ, 464, 943
Kjeldsen H., Bedding T. R., 1995, A&A, 293, 87
Kjeldsen H., Bedding T. R., 2001, in Wilson A., Pallé P. L., eds, ESA SP-464, SOHO 10/GONG 2000 Workshop, Helio- and Asteroseismology at the Dawn of the Millennium. ESA Publications, Noordwijk. p. 361
Kjeldsen H. et al., 2005, ApJ, 635, 1281
Kurucz R. L., 1998, available online (http://kurucz.harvard.edu/grids. html)
Lèbre A., de Laverny P., De Medeiros J. R., Charbonnel C., da Silva L., 1999, A&A, 345, 936
Maeder A., 1975, A&A, 43, 61
Maeder A., Meynet G., 2000, ARA&A, 38, 143
Maeder A., Zahn J.-P., 1998, A&A, 334, 1000
Martić M., Lebrun J.-C., Appourchaux T., Korzennik S. G., 2004, A&A, 418, 295
Mathis S., Palacios A., Zahn J.-P., 2004, A&A, 425, 243
Michaud G., Richard O., Richer J., VandenBerg D. A., 2004, ApJ, 606, 452
Noels A., Montalbán J., Maceroni C., 2004, in Zverko J., Ziznovsky J., Adelman S. J., Weiss W. W., Proc. IAU Symp. 224, The A-star Puzzle. Cambridge Univ. Press, Cambridge, p. 47
Nordström B. et al., 2004, A&A, 418, 989
Osaki J., 1975, PASJ, 27, 237
Popielski B. L., Dziembowski W. A., 2005, Acta Astron., 55, 177
Ribas I., Jordi C., Giménez Á., 2000, MNRAS, 318, L55
Richard O., 2005, in Alecian G., Richard O., Vauclair S., eds, EAS Publications Ser. Vol. 17, Element stratification in Stars: 40 yr of atomic diffusion. EDP Sciences, Les Ulis, p. 43
Richard O., Michaud G., Richer J., 2001, ApJ, 558, 377
Rogers F. J., Nayfonov A., 2002, ApJ, 576, 1064
Roxburgh I. W., Vorontsov S. V., 2003, A&A, 411, 215
Salpeter E. E., 1954, Aust. J. Phys., 7, 373
Samadi R., Goupil M.-J., Alecian E., Baudin F., Georgobiani D., Trampedach R., Stein R., Nordlund Å., 2005, JApA, 26, 171
