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PROJECT SUMMARY (max 3000 characters)

The principal goals of the project are the observational and theoretical
investigation of complex cosmic objects where the processes of dust
scattering, absorption and emission play significant roles. Special
attention will be paid to both linear and circular polarization as
an important source of information on the nature of dust grains.
The main areas of the project are:

* Observational analysis of dusty objects (evolved stars, young
stellar objects, comets, stars with protoplanetary discs and planets)
in polarized light, physical modelling and interpretation of the
observations.

* Mathematical modelling, development of sophisticated radiative
transfer methods and software based on the Monte Carlo method.

* Development of light scattering theory and computer codes
to calculate the optical properties of non-spherical
inhomogeneous particles and laboratory measurements of light
scattering characteristics of irregularly shaped particles.

* Creation of an electronic database containing information and tools
required for efficient consideration of light scattering in astronomy.

The research activities will include:

* Photometric, polarimetric, spectral, imaging observations of
selected late-type stars, young stellar objects, comets, stars with
circumstellar discs and planets and their interpretation.

* Development of the Monte Carlo technique including new criteria for the
estimation of variance finiteness, optimization of weight modeling of
trajectories in optically thin and optically thick media, etc. and
creation of new computer codes for the calculation of polarized
radiation transfer in dusty cosmic objects contained aligned
non-spherical scatterers.

* Applications of special versions of the separation of variables method
and new approaches to the T-matrix method for computation of the
optical properties of layered non-spherical particles and direct
measurements of the characteristics of light scattered by submicron
particles.

* Updating and extension of the existing Jena-Petersburg database of
optical constants for astronomy (JPDOC) and the database of optical
properties of non-spherical scatterers (DOP), their supplementation
with data from laboratory experiments, radiative transfer codes,
atlas of models, etc.

The following results are expected:

* Detailed models of several dusty objects including estimates of
characteristics of cosmic dust grains and their spatial distribution,
conclusions on the properties of magnetic fields and the relationship
between various dust populations, new knowledge on the evolutionary
state of different objects.

* Various Monte Carlo codes which will give the possibility to calculate the
wavelength dependencies of extinction and polarization, spectral energy
distributions, the profiles of dusty features, images and polarization
maps of dusty circumstellar environments from ultraviolet
to sub-millimetre wavelengths.

* A series of efficient numerical codes based on exact and approximate
methods in light scattering by small particles, a set of experimentally
obtained data on the characteristics of light scattered by particles of
different kinds.

* An unique WWW database which will cover all aspects of light scattering
applications in astronomy - from the laboratory measurement of optical
constants and the optical properties of various cosmic dust analogs,
to sophisticated radiative transfer codes and an atlas of models for
different dust configurations, distributions of sources, grain properties.