Linear Polarization of Brown Dwarfs

Pitann, J.; Goldman, B.; Osorio, M. R. Z.; Bailer-Jones, C. A. L.; Béjar, V. S.; Caballero, J. A.; Henning, T.
Referencia bibliográfica

Astronomical Polarimetry 2008: Science from Small to Large Telescopes. Proceedings of a Workshop held at Fairmont Le Manoir Richelieu, La Malbaie, Quebec, Canada 6-11 July 2008. Edited by Pierre Bastien, Nadine Manset, Dan P. Clemens, and Nicole St-Louis. ASP Conference Series, Vol. 449. San Francisco: Astronomical Society of the Pacific, 2012., p.308

Fecha de publicación:
11
2011
Número de autores
7
Número de autores del IAC
0
Número de citas
0
Número de citas referidas
0
Descripción
L-type ultra-cool dwarfs are known to have a dusty atmosphere. Surface heterogeneities, due to cloud patterns or rotationally-induced oblateness, would result in an imperfect polarization cancellation and a small, but non-zero net polarization. The measurement of linear polarization could shed light on the dust distribution and oblateness of those objects, as well as the particle size distribution. Young brown dwarfs share many of their stellar counterparts' characteristics, including the presence of circumstellar disks. Dust scattering within the disk also leads to polarization, depending on the disk properties and inclination angle. We have obtained linear polarization observations for a sample of young and old brown dwarfs taken with FORS1 at the VLT. We present our measurements and compare our results with predictions from disk and photospheric models.