dc.contributor.author |
Sengupta, S |
|
dc.date.accessioned |
2008-07-11T11:08:33Z |
|
dc.date.available |
2008-07-11T11:08:33Z |
|
dc.date.issued |
2008-08 |
|
dc.identifier.citation |
The Astrophysical Journal Letters, Vol. 683, No. 2, pp. L195 – L198 |
en |
dc.identifier.uri |
http://hdl.handle.net/2248/2641 |
|
dc.description.abstract |
The peak amplitude of linear polarization detected recently from an extraso-
lar hot giant planet HD 189733b, is a few times of 10−4 , more than an order of
magnitude higher than all theoretical predictions. Rayleigh scattering off H2 and
He may although give rise to a planet-star flux ratio of the order of 10−4 in the
blue band, it cannot account for the high polarization unless the planet has an
unusually extended atmosphere. Therefore, it is suggested that the high polariza-
tion should be attributed to the presence of a thin cloud of sub-micron size dust
grains in the upper visible atmosphere which supports the observational finding
of an almost feature-less transmission spectrum in the optical with no indication
of the expected alkaline absorption features. It is found that the polarimetry
observation allows for a small eccentricity of the orbit that is predicted from the
time delay of the secondary eclipse of the planet. The estimated longitude of the
ascending node is 16o ± 6 which interestingly coincides with the observationally
inferred location of the peak hemisphere-integrated brightness. |
en |
dc.format.extent |
109419 bytes |
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dc.format.mimetype |
application/pdf |
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dc.language.iso |
en |
en |
dc.publisher |
IOP Science |
en |
dc.relation.uri |
http://iopscience.iop.org/1538-4357/683/2/L195 |
|
dc.rights |
© The American Astronomical Society. All rights reserved. |
|
dc.subject |
Planetary Systems |
en |
dc.subject |
Stars:Individual(HD 189733) |
en |
dc.subject |
Polarization |
|
dc.subject |
Scattering |
|
dc.title |
Cloudy atmosphere of the extra-solar planet HD189733b: A possible explanation of the detected B-band polarization |
en |
dc.type |
Article |
en |