Publications
of the
MPIfR
Optical & Infrared
Interferometry Group
J.M. Winters, T. Blöcker, K.-H. Hofmann, and G. Weigelt:
Confronting the evolving clumpy shell structure of IRC+10216 with
time dependent dust shell models
Astronomische Gesellschaft Abstract Series (AGM 18, P96)
Five Days of Creation: Astronomy with Large Telescopes from Ground and Space
Annual Scientific Meeting of the Astronomische Gesellschaft
at the Joint European and National Meeting JENAM 2001 of the
European Astronomical Society and the Astronomische Gesellschaft,
Sep 10-15, 2001, Munich, Germany
Abstract.
The prototypical dust enshrouded carbon Mira IRC +10216 is known to exhibit
intrinsic structural changes on a time scale of the order of 10 yr as
revealed, e.g., by CO infrared line profiles, its infrared light curves, or by
high spatial resolution monitoring in the infrared. In particular, the light
curves obtained over 35 yr indicate a possible periodicity on a ~20 yr
time scale, which suggests that a recurrent phenomenon might lead to the
observed variations in the CO first overtone line profiles and the clumpy
spatial structure. Such multi-periodicity time scales, which correspond to
several (~10) pulsation periods of the
star, are predicted by consistent hydrodynamical models which include a
proper treatment of dust formation. In these models discrete dust layers
form on a time scale which is longer than the typical pulsation period of AGB
stars (Fleischer et al. 1995).
In the high spatial resolution images of IRC +10216 (Osterbart et al. 2000)
several components can be identified, whose structure and brightness evolve
considerably within only a few years. To shed some light on this evolution,
we apply a spherically symmetric, time-dependent dust shell model which
consistently describes the coupled system of hydrodynamics, chemistry,
dust formation and radiative transfer (Winters et al. 2000) and confront the
kinematics and brightness variations predicted by this model with the high
spatial resolution observations of IRC +10216.
Fleischer A.J., Gauger A., Sedlmayr E., 1995, A&A 297, 543
Osterbart R., Balega Y.Y., Blöcker T., et al., 2000, A&A 357, 169
Winters J.M., Le Bertre T., Jeong K.S., et al., 2000, A&A 361, 641