J/ApJ/707/167 Transiting planetary system WASP-18 (Southworth+, 2009)
Physical properties of the 0.94-day period transiting planetary system WASP-18.
Southworth J., Hinse T.C., Dominik M., Glitrup M., Jorgensen U.G.,
Liebig C., Mathiasen M., Calchi Novati S., Dreizler S., Finet F.,
Harpsoe K., Hessman R., Hundertmark M., Maier G., Mancini L., Maxted P.F.L.,
Rahvar S., Ricci D., Scarpetta G., Skottfelt J., Snodgrass C., Surdej J.,
Zimmer F.
<Astrophys. J. 707, 167 (2009)>
=2009ApJ...707..167S 2009ApJ...707..167S
ADC_Keywords: Planets ; Photometry
Keywords: stars: planetary systems - methods: data analysis -
methods: observational - techniques: photometric
Abstract:
We present high-precision photometry of five consecutive transits of
WASP-18, an extrasolar planetary system with one of the shortest
orbital periods known. Through the use of telescope defocussing we
achieve a photometric precision of 0.47 to 0.83mmag per observation
over complete transit events. The data are analysed using the JKTEBOP
code and three different sets of stellar evolutionary models. We point
out that seven of the nine known massive transiting planets have
eccentric orbits, whereas significant orbital eccentricity has been
detected for only four of the 46 less massive planets. This may
indicate that there are two different populations of transiting
planets, but could also be explained by observational biases. Further
radial velocity observations of low-mass planets will make it possible
to choose between these two scenarios.
Description:
Light curves of five transit events of the transiting extrasolar
planetary system WASP-18 are presented. The data were obtained using
the Danish 1.5m telescope and DFOSC camera at ESO La Silla in 2009,
with substantial telescope defocussing in order to improve the
photometric precision of the observations. A Johnson V filter and
exposure times of 80s were used.
Objects:
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RA (2000) DE Designation(s)
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01 37 25.0 -45 40 40 WASP-18 = HD 10069
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wasp18.dat 36 629 Defocussed photometry of WASP-18 (table2)
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See also:
J/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009)
J/MNRAS/396/1023 : Transiting planetary system WASP-5 (Southworth+, 2009)
J/AJ/137/3826 : Two transits of the giant planet WASP-4b (Winn+, 2009)
J/A+A/501/785 : Discovery and characterization of WASP-6b (Gillon+, 2009)
J/A+A/502/391 : WASP-13b photometry and radial velocities (Skillen+, 2009)
Byte-by-byte Description of file: wasp18.dat
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Bytes Format Units Label Explanations
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1- 14 F14.6 d BJD Barycentric JD for the midpoint of observation
17- 25 F9.6 mag Vmag Differential V-band magnitude of WASP-18
29- 36 F8.6 mag e_Vmag Measurement error of the R-band magnitude
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Acknowledgements:
John Southworth, jkt(at)astro.keele.ac.uk
(End) John Southworth [Keele Univ., UK], Patricia Vannier [CDS] 26-Nov-2009