J/A+A/588/L6 WASP-12 transit light curves (Maciejewski+ 2016)
Departure from the constant-period ephemeris for the transiting planet
WASP-12 b.
Maciejewski G., Dimitrov D., Fernandez M., Sota A., Nowak G., Ohlert J.,
Nikolov G., Bukowiecki L., Hinse T.C., Palle E., Tingley B.,
Kjurkchieva D., Lee J.W., Lee C.-U.
<Astron. Astrophys. 588, L6 (2016)>
=2016A&A...588L...6M 2016A&A...588L...6M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Photometry, CCD
Keywords: stars: individual: WASP-12 -
planets and satellites: individual: WASP-12 b -
planet-star interactions
Abstract:
Most hot Jupiters are expected to spiral in toward their host stars
because the angular momentum of the orbital motion is transferred to
the stellar spin. Their orbits can also precess as a result of
planet-star interactions. Calculations show that both effects might be
detected for the very-hot exoplanet WASP-12 b using the method of
precise transit-timing over a time span of about 10yr. We acquired
new precise light curves for 29 transits of WASP-12 b, spanning four
observing seasons from November 2012 to February 2016. New mid-transit
times, together with those from the literature, were used to refine
the transit ephemeris and analyze the timing residuals. We find that
the transit times of WASP-12 b do not follow a linear ephemeris with a
5-σ confidence level. They may be approximated with a quadratic
ephemeris that gives a change rate in the orbital period of
(-2.56±0.40)x10-2s/yr. The tidal quality parameter of the host
star was found to be equal to 2.5x105, which is similar to
theoretical predictions for Sun-like stars. We also considered a model
in which the observed timing residuals are interpreted as a result of
the apsidal precession. We find, however, that this model is
statistically less probable than the orbital decay.
Description:
New Light curves for transits of WASP-12 b observed in 2012-2016 are
given. Data were collected with 0.6-2.56-m telescopes. In addition,
the light curves that were obtained from re-analysis of literature
data are attached. Details on observations and data processing are
given in the source paper.
Objects:
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RA (2000) DE Designation(s)
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06 30 32.79 +29 40 20.3 WASP-12 = TYC 1891-1178-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
w12new.dat 36 11657 New light curves for transits of WASP-12 b
w12rer.dat 36 7038 Re-reduced light curves from literature
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See also:
J/ApJ/720/872 : A spectropolarimetric analysis of WASP-12 (Fossati+, 2010)
J/A+A/528/A65 : WASP-12b transits (Maciejewski+, 2011)
J/A+A/551/A108 : Multi-site obs. of WASP-12 b transit (Maciejewski+, 2013)
Byte-by-byte Description of file: w12new.dat w12rer.dat
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Bytes Format Units Label Explanations
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1- 11 F11.6 d BJD Barycentric Julian date in Barycentric
Dynamical Time (BJD-2450000)
12- 20 F9.6 --- Flux Normalized flux
21- 29 F9.6 --- e_Flux Flux error
30- 34 A5 --- TelCode Telescope code
36 A1 --- Filt [RV- ] Filter name
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Acknowledgements:
Gracjan Maciejewski, gmac(at)umk.pl
(End) G. Maciejewski [N. Copernicus Univ., Poland], P. Vannier [CDS] 02-Mar-2016