Potassium detection in the clear atmosphere of a hot-Jupiter FORS2 transmission spectroscopy of WASP-17b

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10334076" target="_blank" >RIV/00216208:11320/16:10334076 - isvavai.cz</a>

Alternative codes found

RIV/67985815:_____/16:00470385

Result on the web

<a href="http://dx.doi.org/10.1051/0004-6361/201629090" target="_blank" >http://dx.doi.org/10.1051/0004-6361/201629090</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1051/0004-6361/201629090" target="_blank" >10.1051/0004-6361/201629090</a>

Result language

angličtina

Original language name

Potassium detection in the clear atmosphere of a hot-Jupiter FORS2 transmission spectroscopy of WASP-17b

Original language description

We present FORS2 (attached to ESO's Very Large Telescope) observations of the exoplanet WASP-17b during its primary transit, for the purpose of differential spectrophotometry analysis. We use the instrument in its Mask eXchange Unit (MXU) mode to simultaneously obtain low resolution spectra of the planet hosting star, as well as several reference stars in the field of view. The integration of these spectra within broadband and smaller 100 angstrom bins provides us with "white" and spectrophotometric light curves, from 5700 to 8000 angstrom. Through modelling the white light curve, we obtain refined bulk and transit parameters of the planet, as well as wavelength-dependent variations of the planetary radius from smaller spectral bins through which the transmission spectrum is obtained. The inference of transit parameters, as well as the noise statistics, is performed using a Gaussian Process model. We achieve a typical precision in the transit depth of a few hundred parts per million from various transit light curves. From the transmission spectra we rule out a flat spectrum at >3 sigma and detect marginal presence of the pressure-broadened sodium wings. Furthermore, we detect the wing of the potassium absorption line in the upper atmosphere of the planet with 3 sigma confidence, both facts pointing to a relatively shallow temperature gradient in the atmosphere. These conclusions are mostly consistent with previous studies of this exo-atmosphere, although previous potassium measurements have been inconclusive.

Czech name

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Czech description

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Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

BN - Astronomy and celestial mechanics, astrophysics

OECD FORD branch

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Project

<a href="/en/project/LG14013" target="_blank" >LG14013: Tycho Brahe: Supporting Ground-based Astronomical Observations</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2016

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Astronomy and Astrophysics [online]

ISSN

1432-0746

e-ISSN

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Volume of the periodical

596

Issue of the periodical within the volume

listopad

Country of publishing house

PL - POLAND

Number of pages

14

Pages from-to

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UT code for WoS article

000390797900083

EID of the result in the Scopus database

2-s2.0-85002044882