Publications
of the
MPIfR Optical & Infrared Interferometry Group
Blöcker,
T., Balega, Y., Hofmann, K.-H.,
Men'shchik
ov, A., Weigelt, G., and Winters, J.M.
Bispectrum speckle interferometry and future long-baseline
interferometry of the carbon
star IRC+10216
in: W.A. Traub
(ed.),
Interferometry for Optical Astronomy II, SPIE Conf. Vol. 4838
(2003)
Abstract.
We present near-infrared (JHK) bispectrum speckle-interferometry
monitoring
of IRC+10216 obtained with the SAO 6m telescope. The present speckle
observatio
ns
covering baselines up to 6m provide important complementary
informations
for future long-baseline interferometry. To disentangle the apparent
motions
of the various IRC+10216 components and to reveal the location of the
central
star, future high-resolution observations are of utmost value for the
interpret
ation
of this astrophysical key object. The J-, H-, and K-band resolutions of
our speckle observations are 50 mas, 56 mas, and 73 mas, resp. The
K-band observati
ons
cover 8 different epochs from 1995 to 2001 and show the dynamical
evolution
of the dust shell which consists of several compact components within a
200
milli-arcsecond radius. Our recent two-dimensional radiative transfer
modelling
has shown that the central star is probably not located at the
brightest
dust-shell component A but at the position of the northern component B.
The
bright and compact component A is the southern lobe of a bipolar
structure.
The changes of the dust-shell structure can be related to corresponding
changes
of the optical depth caused, for instance, by mass-loss variations. The
present observations are consistent with the predictions of
hydrodynamical models
that enhanced dust formation takes place on a timescale of several
pulsational
cycles.
You can get this publication ...