Orbital alignment and star-spot properties in the WASP-52 planetary system
Research output: Contribution to journal › Journal article › Research › peer-review
We report 13 high-precision light curves of eight transits of the
exoplanet WASP-52b, obtained by using four medium-class telescopes,
through different filters, and adopting the defocussing technique. One
transit was recorded simultaneously from two different observatories and
another one from the same site but with two different instruments,
including a multi-band camera. Anomalies were clearly detected in five
light curves and modelled as starspots occulted by the planet during the
transit events. We fitted the clean light curves with the jktebop code,
and those with the anomalies with the prism+gemc codes in order to
simultaneously model the photometric parameters of the transits and the
position, size and contrast of each starspot. We used these new light
curves and some from the literature to revise the physical properties of
the WASP-52 system. Starspots with similar characteristics were detected
in four transits over a period of 43 days. In the hypothesis that we are
dealing with the same starspot, periodically occulted by the transiting
planet, we estimated the projected orbital obliquity of WASP-52b to be
lambda = 3.8 \pm 8.4 degree. We also determined the true orbital
obliquity, psi = 20 \pm 50 degree, which is, although very uncertain,
the first measurement of psi purely from starspot crossings. We finally
assembled an optical transmission spectrum of the planet and searched
for variations of its radius as a function of wavelength. Our analysis
suggests a flat transmission spectrum within the experimental
uncertainties.
Original language | English |
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Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 465 |
Issue number | 1 |
Pages (from-to) | 843-857 |
ISSN | 0035-8711 |
DOIs | |
Publication status | Published - 1 Feb 2017 |
Links
- http://arxiv.org/pdf/1608.02001
Submitted manuscript
ID: 170454927