Please use this identifier to cite or link to this item:
http://hdl.handle.net/2248/4899
Title: | Optical linear polarization in ultra cool dwarfs: A tool to probe dust in the ultra cool dwarf atmospheres |
Authors: | Tata, R Martin, E. L Sengupta, S Phan-Bao, N Zapatero Osorio, M. R Bouy, H |
Keywords: | Polarization Atmospheric Effects Brown Dwarfs Stars: Low-Mass |
Issue Date: | Dec-2009 |
Publisher: | European Space Agency |
Citation: | Astronomy and Astrophysics, Vol. 508, No. 3, pp. 1423 - 1427 |
Abstract: | Aims.Recent studies have detected linear polarization in L dwarfs in the optical I band. Theoretical models have been developed to explain this polarization. These models predict higher polarization at shorter wavelengths. We discuss the polarization in the R and I band of 4 ultra cool dwarfs. Methods.We report linear polarization measurements of 4 ultra cool dwarfs in the R and I bands using the Intermediate dispersion Spectrograph and Imaging System (ISIS) mounted on the 4.2m William Herschel Telescope (WHT). Results.As predicted by theoretical models, we find a higher degree of polarization in the R band when compared to polarization in the I band for 3/4 of these ultra cool dwarfs. This suggests that dust scattering asymmetry is caused by oblateness >.We also show how these measurements fit the theoretical models. A case for variability of linear polarization is found, which suggests the presence of randomly distributed dust clouds. We also discuss one case for the presence of a cold debris disk. |
Description: | Open Access |
URI: | http://hdl.handle.net/2248/4899 |
ISSN: | 0004-6361 |
Appears in Collections: | IIAP Publications |
Files in This Item:
File | Description | Size | Format | |
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Optical linear polarization in ultra cool dwarfs | Open Access | 137.37 kB | Adobe PDF | ![]() View/Open |
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