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

Kód výsledku v 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>

Nalezeny alternativní kódy

RIV/67985815:_____/16:00470385

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BN - Astronomie a nebeská mechanika, astrofyzika

OECD FORD obor

—

Projekt

<a href="/cs/project/LG14013" target="_blank" >LG14013: Tycho Brahe: projekt podpory pozemních astronomických pozorování</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Astronomy and Astrophysics [online]

ISSN

1432-0746

e-ISSN

—

Svazek periodika

596

Číslo periodika v rámci svazku

listopad

Stát vydavatele periodika

PL - Polská republika

Počet stran výsledku

14

Strana od-do

—

Kód UT WoS článku

000390797900083

EID výsledku v databázi Scopus

2-s2.0-85002044882