Bibcode
Goldman, B.; Pitann, J.; Osorio, M. R. Zapatero; Bailer-Jones, C. A. L.; Béjar, V. S.; Caballero, J. A.; Henning, Th.
Referencia bibliográfica
COOL STARS, STELLAR SYSTEMS AND THE SUN: Proceedings of the 15th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun. AIP Conference Proceedings, Volume 1094, pp. 525-528 (2009).
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2
2009
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0
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Descripción
Ultra-cool dwarfs with effective temperatures between ~1400 K and ~2200
K are known to have dusty atmospheres. Asymmetries of the dwarf surface
may arise from rotationally-induced flattening and dust-cloud coverage,
and may result in non-zero linear polarisation through dust scattering.
Here we present our linear polarimetric imaging measurements using FORS1
at the Very Large Telescope, in Paranal, in the Bessel I filter, and for
a subset of our sample in the Bessel R and the Gunn z filters. We report
a polarisation degree of (-0.31+/-+0.07)% for LHS102BC. We fail to
detect linear polarisation in the rest of our sample, with upper-limits
on the polarisation degree of each object of 0.09% to 0.76% (95% of
confidence level), depending on the targets and the bands. For six
targets, our data indicate polarisation degrees smaller (at the
2-σ level) than previously reported.