J/MNRAS/426/1338 Transiting planetary system WASP-17 (Southworth+, 2012)
High-precision photometry by telescope defocusing.
IV. Confirmation of the huge radius of WASP-17b.
Southworth J., Hinse T.C., Dominik M., Fang X.-S., Harpsoe K.,
Jorgensen U.G., Kerins E., Liebig C., Mancini L., Skottfelt J.,
Anderson D.R., Smalley B., Tregloan-Reed J., Wertz O., Alsubai K.A.,
Bozza V., Calchi Novati S., Dreizler S., Gu S.-H., Hundertmark M.,
Jessen-Hansen J., Kains N., Kjeldsen H., Lund M.N., Lundkvist M.,
Mathiasen M., Penny M.T., Rahvar S., Ricci D., Scarpetta G., Snodgrass C.,
Surdej J.
<Mon. Not. R. Astron. Soc., 426, 1338-1348 (2012)>
=2012MNRAS.426.1338S 2012MNRAS.426.1338S
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry
Keywords: stars: planetary systems - methods: data analysis -
methods: observational - techniques: photometric
Abstract:
We present photometric observations of four transits in the WASP-17
planetary system, obtained using telescope defocusing techniques and
with scatters reaching 0.5mmag per point. Our revised orbital period
is 4.0±0.6s longer than previous measurements, a difference of
6.6σ, and does not support the published detections of orbital
eccentricity in this system. We model the light curves using the
JKTEBOP code and calculate the physical properties of the system by
recourse to five sets of theoretical stellar model predictions. The
resulting planetary radius, Rb=1.932±0.052±0.010RJup
(statistical and systematic errors, respectively), provides
confirmation that WASP-17b is the largest planet currently known. All
14 planets with radii measured to be greater than 1.6RJupare found
around comparatively hot (Teff>5900K) and massive
(MA>1.15M☉) stars. Chromospheric activity indicators are
available for eight of these stars, and all imply a low activity
level. The planets have small or zero orbital eccentricities, so tidal
effects struggle to explain their large radii.
Description:
A light curve of four transits of the extrasolar planetary system
WASP-17 is presented. The data were obtained using the Danish 1.5m
telescope and DFOSC camera at ESO La Silla in 2012, with substantial
telescope defocussing in order to improve the photometric precision of
the observations. A Cousins R filter and exposure times of 120s were
used.
Objects:
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RA (2000) DE Designation(s)
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15 59 50.95 -28 03 42.3 WASP-17 = TYC 6787-1927-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wasp17.dat 33 494 Defocussed photometry of WASP-17
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See also:
J/MNRAS/396/1023 : Transiting planetary system WASP-5 (Southworth+, 2009)
J/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009)
J/ApJ/707/167 : Transiting planetary system WASP-18 (Southworth+, 2009)
J/MNRAS/408/1680 : Transiting planetary system WASP-2 (Southworth+, 2010)
J/A+A/527/A8 : Transiting planetary system WASP-7 (Southworth+, 2011)
J/MNRAS/420/2580 : Four transits of HAT-P-13 (Southworth+, 2012)
J/MNRAS/422/3099 : Transit of HAT-P-5 (Southworth+, 2012)
Byte-by-byte Description of file: wasp17.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d BJD Barycentric JD for the midpoint of
observation (TDB)
15- 23 F9.6 mag dRmag Differential R-band magnitude of WASP-17
25- 33 F9.6 mag e_dRmag Measurement error of the R-band magnitude
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Acknowledgements:
John Southworth, astro.js(at)keele.ac.uk
References:
Southworth et al., Paper I 2009MNRAS.396.1023S 2009MNRAS.396.1023S, Cat. J/MNRAS/396/1023
Southworth et al., Paper II 2009MNRAS.399..287S 2009MNRAS.399..287S, Cat. J/MNRAS/399/287
Southworth et al., Paper III 2010MNRAS.408.1680S 2010MNRAS.408.1680S, Cat. J/MNRAS/408/1680
(End) John Southworth [Keele Univ., UK], Patricia Vannier [CDS] 12-Aug-2013