Hostname: page-component-586b7cd67f-l7hp2 Total loading time: 0 Render date: 2024-11-30T16:52:14.743Z Has data issue: false hasContentIssue false

Young Binaries as a Test for Pre-Main Sequence Evolutionary Tracks

Published online by Cambridge University Press:  12 July 2007

Hans Zinnecker*
Affiliation:
Astrophysikalisches Institut Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany email: [email protected]
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Observations of young low-mass binaries (t ≲ 107 yr, M ≲ 3 M_⊙) can be used to calibrate pre-Main Sequence (pre-MS) evolutionary tracks. Recent high angular resolution HST/FGS, speckle, and long-baseline interferometry have resolved the astrometric orbits of a few SB2 pre-MS binaries and have provided the individual dynamical masses of their components as well as the system orbital parallaxes. Spectroscopic fits and filter photometry have permitted to determine SpT (temperatures) and a good estimate of the absolute magnitude (bolometric luminosity) of the components, which in turn allows one to place the components on a theoretical HR-diagram. In this way, one can check (a) whether the measured dynamical masses agree with the predicted masses on the tracks and (b) whether both components lie on an isochrone, as they should for a coeval physical pair of stars.

With a sufficiently large sample of different masses and ages of resolved SB2 systems, most of the parameter space of pre-MS tracks can be tested, even for very low stellar masses (M < 0.5 M_⊙) and very young ages (< 2 Myr). This is a prerequisite in order to derive the IMF and star formation history in very young clusters and associations.

Type
Contributed Papers
Copyright
Copyright © International Astronomical Union 2007

References

Baraffe, I., Chabrier, G., Allard, F., & Hauschildt, P.H. 1995, ApJ 446, L35 (B98)CrossRefGoogle Scholar
Boden, A.F. et al. . 2005, ApJ 635, 442 CrossRefGoogle Scholar
Brandner, W. & Zinnecker, H. 1997, A&A 321, 220 Google Scholar
Casey, B.W., Mathieu, R.D., Vaz, L.P.R., Andersen, J., & Suntzeff, N.B. 1998, AJ 115, 1617 CrossRefGoogle Scholar
Costero, R., Poveda, A. & Echevarría, J. 2007 these proceedings, 130Google Scholar
Covino, E., Catalano, S., Frasca, A., Marilli, E., Fernández, M., Alcalá, J.M., Melo, C., Paladino, R., Sterzik, M.F., & Stelzer, B. 2000, A&A 361, L49 Google Scholar
D'Antona, F. & Mazzitelli, I. 1994, ApJS 90, 467 CrossRefGoogle Scholar
D'Antona, F. & Mazzitelli, I. 1997, Mem. Soc. Astr. It. 68, 807 (DM97)Google Scholar
D'Antona, F., Ventura, P., & Mazzitelli, I. 2000, ApJ 543, L77 CrossRefGoogle Scholar
Duchêne, G., Beust, H., Adjali, F., Konopacky, Q.M., & Ghez, A.M. 2006, A&A 457, L9 Google Scholar
Guenther, E., Esposito, M., Mundt, R., Covino, E., Alcalá, J.M., & Stecklum, B. 2007, astro-ph/2268GGoogle Scholar
Guenther, E.W., Covino, E., Alcalá, J.M., Esposito, M., & Mundt, R. 2005, A&A 433, 629 Google Scholar
Herbig, G.H. & Griffin, R.F. 2006, AJ 132, 1763 CrossRefGoogle Scholar
Hillenbrand, L.A. & White, R.J. 2004, ApJ 604, 741 CrossRefGoogle Scholar
Jayawardhana, R. & Ivanov, V.D. 2006, Science 313, 1279 CrossRefGoogle Scholar
Kopal, Z. 1986, Of stars and men. Reminiscences of an astronomer (Bristol: Hilger)Google Scholar
Mathieu, R.D. 1994, ARA&A 32, 465 Google Scholar
Mathieu, R., Stassun, K., Baraffe, I., Simon, M., & White, R. 2006, in: Reipurth, B., Jewitt, D., Keil, K. (eds.), Protostars and Planets V, in pressGoogle Scholar
Mazeh, T., Simon, M., Prato, L., Markus, B., & Zucker, S. 2003, ApJ 599, 1344 CrossRefGoogle Scholar
Melo, C.H.F., Covino, E., Alcalá, J.M., & Torres, G. 2001, A&A 378, 898 Google Scholar
Palla, F. & Stahler, S.W. 1999, ApJ 525, 772 (PS99)CrossRefGoogle Scholar
Popper, D.M. 1987, ApJ 313, L81 CrossRefGoogle Scholar
Prato, L., Greene, T.P., & Simon, M. 2003, ApJ 584, 853 CrossRefGoogle Scholar
Prato, L., Simon, M., Mazeh, T., Zucker, S., & McLean, I.S. 2002, ApJ 579, L99 CrossRefGoogle Scholar
Schaefer, G.H., Simon, M., & Prato, L. 2006, in: Richichi, A., Paresce, F. (eds.), The Power of Optical/IR Interferometry, in pressGoogle Scholar
Schertl, D., Balega, Y.Y., Preibisch, Th., & Weigelt, G. 2003, A&A 402, 267 Google Scholar
Siess, L., Dufour, E., & Forestini, M. 2000, A&A 358, 593 (S00)Google Scholar
Simon, M., Ghez, A.M., & Leinert, Ch. 1993, ApJ 408, L33 CrossRefGoogle Scholar
Stahler, S.W. & Palla, F. 2004, The Formation of Stars (Wiley-VCH)CrossRefGoogle Scholar
Stassun, K.G., Mathieu, R.D., & Valenti, J.A. 2006, Nature 440, 311 CrossRefGoogle Scholar
Stassun, K.G., Mathieu, R.D., Vaz, L.P.R., Stroud, N., & Vrba, F.J. 2004, ApJS 151, 357 CrossRefGoogle Scholar
Steffen, A.T., Mathieu, R.D., Lattanzi, M.G., Latham, D.W., Mazeh, T., Prato, L., Simon, M., Zinnecker, H., & Loreggia, D. 2001, AJ 122, 997 CrossRefGoogle Scholar
Wuchterl, G. & Tscharnuter, W.M. 2003, A&A 398, 1081 Google Scholar
Yi, S.K., Kim, Y.-C., & Demarque, P. 2003, ApJS 144, 259 (Yi/Yale)CrossRefGoogle Scholar
Zinnecker, H. 1984, Ap&SS 99, 41 Google Scholar
Zinnecker, H. & Correia, S. 2004, in: Hilditch, R.W., Hensberge, H., Pavlovski, K. (eds.), Spectroscopically and Spatially Resolving the Components of the Close Binary Stars, ASP Conference Series, Vol. 318 (San Francisco: Astronomical Society of the Pacific), p. 34Google Scholar