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Author Marley, Mark S. ♦ Sengupta, S.
Source Indian Institute of Astrophysics
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Polarization ♦ Scattering ♦ Planets and Satellites:Atmospheres ♦ Stars:Atmosphere
Description It is becoming clear that the atmospheres of the young, self-luminous extrasolar gi- ant planets imaged to date are dusty. Planets with dusty atmospheres may exhibit detectable amounts of linear polarization in the near-infrared, as has been observed from some eld L dwarfs. The asymmetry required in the thermal radiation eld to produce polarization may arise either from the rotation-induced oblateness or from surface inhomogeneities, such as partial cloudiness. While it is not possible at present to predict the extent to which atmospheric dynamics on a given planet may produce surface inhomogeneities substantial enough to produce net non-zero disk integrated polarization, the contribution of rotation-induced oblateness can be estimated. Using a self-consistent, spatially homogeneous atmospheric model and a multiple scatter- ing polarization formalism for this class of exoplanets, we show that polarization on the order of 1% may arise due to the rotation-induced oblateness of the planets. The observed polarization may be even higher if surface inhomogeneities exist and play a signi catnt role. Polarized radiation from self-luminous gas giant exoplanets, if de- tected, provides an additional tool to characterize these young planets and a new method to constrain their surface gravity and masses.
ISSN 13652966
Educational Use Research
Education Level UG and PG
Learning Resource Type Article
Publisher Institution Wiley-Blackwell
Journal Monthly Notices of the Royal Astronomical Society
Volume Number 417
Issue Number 4
Page Count 28,742,881
Starting Page 1
Ending Page 28742881