J/MNRAS/408/1680 Transiting planetary system WASP-2 (Southworth+, 2010)
High-precision photometry by telescope defocussing.
III. The transiting planetary system WASP-2.
Southworth J., Mancini L., Calchi Novati S., Dominik M., Glitrup M.,
Hinse T.C., Jorgensen U.G., Mathiasen M., Ricci D., Maier G., Zimmer F.,
Bozza V., Browne P., Bruni I., Burgdorf M., Dall'Ora M., Finet F.,
Harpsoe K., Hundertmark M., Liebig C., Rahvar S., Scarpetta G.,
Skottfelt J., Smalley B., Snodgrass C., Surdej J.
<Mon. Not. R. Astron. Soc. 408, 1680 (2010)>
=2010MNRAS.408.1680S 2010MNRAS.408.1680S
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry
Keywords: stars: planetary systems - methods: data analysis -
methods: observational - techniques: photometric
Abstract:
We present high-precision photometry of three transits of the
extrasolar planetary system WASP-2, obtained by defocussing the
telescope, and achieving point-to-point scatters of between 0.42 and
0.73mmag. These data are modelled using the JKTEBOP code, and taking
into account the light from the recently-discovered faint star close
to the system. The physical properties of the WASP-2 system are
derived using tabulated predictions from five different sets of
stellar evolutionary models, allowing both statistical and systematic
error bars to be specified. We find the mass and radius of the planet
to be Mb=0.847±0.038±0.024Mjup and
Rb=1.044±0.029±0.015Rjup. It has a low equilibrium temperature
of 1280±21K, in agreement with a recent finding that it does not
have an atmospheric temperature inversion.
Description:
Light curves of four transits of the extrasolar planetary system
WASP-2 are presented, obtained with substantial telescope defocussing
in order to improve the photometric precision of the observations.
Three of the datasets were obtained using the Danish 1.5m telescope,
DFOSC camera and R filter at ESO La Silla in 2010. One of these
datasets was affected by cloud, so was not included in our analysis
but is archived with the rest of the data in case it is useful to
others. The fourth dataset was obtained with the Loiano 1.52m
telescope, BFOSC camera and a Gunn r filter. We also include a
datafile containing the times of transit midpoint from our own data
and from other sources.
Objects:
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RA (2000) DE Designation(s)
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20 30 54.13 +06 25 46.4 WASP-2 = 1SWASP J203054.12+062546.4
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
wasp2a.dat 33 128 Photometry of WASP-2 on 2009/06/03 (Danish)
wasp2b.dat 33 95 Photometry of WASP-2 on 2009/08/11 (cloudy)
wasp2c.dat 33 83 Photometry of WASP-2 on 2009/08/24 (Danish)
wasp2d.dat 33 63 Photometry of WASP-2 on 2009/11/11 (Loiano)
tmin.dat 65 28 Times of transit midpoint of WASP-2
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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)
Byte-by-byte Description of file: wasp2a.dat wasp2b.dat wasp2c.dat wasp2d.dat
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Bytes Format Units Label Explanations
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1- 12 F12.6 d BJD(TDB) Barycentric JD for the midpoint of observation
15- 23 F9.6 mag Rmag Differential R-band magnitude of WASP-2
26- 33 F8.6 mag e_Rmag Measurement error of the R-band magnitude
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Byte-by-byte Description of file: tmin.dat
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Bytes Format Units Label Explanations
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1- 11 F11.5 d BJD(TDB) Barycentric JD of time of transit midpoint
14- 20 F7.5 d e_BJD(TDB) Uncertainty in the time of transit midpoint
23- 65 A43 --- Ref Reference for time of transit midpoint
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Acknowledgements:
John Southworth, jkt(at)astro.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
(End) John Southworth [Keele Univ., UK], Patricia Vannier [CDS] 06-Jan-2011