Bibcode
Orsatti, A. M.; Vergne, M. M.; Feinstein, C.; Martinez, R. E.
Bibliographical reference
Memorie della Società Astronomica Italiana, v.77, p.1165 (2006)
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2006
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Description
We present preliminary results from an Open Clusters Polarimetric Survey
which is being developed at La Plata Observatory (Argentina). The aim of
this Survey is to provide clues about the characteristics of the dust
responsible for extinction and polarization in the light from member
stars of Open Clusters, about its galactic distribution and also to
confirm or reject possible memberships of clusters members. At the
present stage we have studied a total of 17 Open Clusters with galactic
longitudes in the 3rd. and 4th. quadrants, in the Southern Milky Way,
with a range in distance of about 800-2300 pc from the Sun and a sample
of about 500 observed individual stars. In each one of these clusters,
we have been able to detect the presence (if any) of intracluster dust
and interstellar dust on direction to the cluster, with auxiliary
observations of non-member stars. Also, we got from these observations
the distribution, size and efficiency of the dust grains which polarize
the star light and the changing directions of the Galactic magnetic
field along the line of sight to each cluster. A very important
byproduct of these studies is the isolation of stars which are
candidates for having an intrinsic component of polarization (with a
non-interstellar origin). Special applications have been found, as for
example in help discussing membership of Cepheids in some Open Clusters,
or detecting the location of energetic phenomena occurred in the past
history of a cluster. The principal aim of this Survey is to develop,
in the near future, a new catalog containing the polarimetric parameters
associated with them. Hence, this is the first polarimetric Survey
devoted not to isolated stars, as in other catalogs, but to a stellar
group at a certain location, immersed in a particular interstellar
medium whose characteristics can be revealed through polarimetry.