J/A+A/630/A89 WASP-12b and WASP-43b griz light curves (Parviainen+, 2019)
Multicolour photometry for exoplanet candidate validation.
Parviainen H., Tingley B., Deeg H.J., Palle E., Alonso R.,
Montanes Rodriguez P., Murgas F., Narita N., Fukui A., Kusakabe N.,
Tamura M., Nishiumi T., Prieto-Arranz J., Klagyivik P., Bejar V.J.S.,
Crouzet N., Mori M., Hidalgo Soto D., Casasayas Barris N., Luque R.
<Astron. Astrophys. 630, A89 (2019)>
=2019A&A...630A..89P 2019A&A...630A..89P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry, SDSS
Keywords: planetary systems - planets and satellites: detection -
methods: statistical - methods: numerical -
methods: data analysis - techniques: photometric
Abstract:
The TESS and PLATO missions are expected to find vast numbers of new
transiting planet candidates. However, only a fraction of these
candidates will be legitimate planets, and the candidate validation
will require a significant amount of follow-up resources. Radial
velocity (RV) follow-up study can be carried out only for the most
promising candidates around bright, slowly rotating, stars. Thus,
before devoting RV resources to candidates, they need to be vetted
using cheaper methods, and, in the cases for which an RV confirmation
is not feasible, the candidate's true nature needs to be determined
based on these alternative methods alone.
We study the applicability of multicolour transit photometry in the
validation of transiting planet candidates when the candidate signal
arises from a real astrophysical source (transiting planet, eclipsing
binary, etc.), and not from an instrumental artefact. Particularly, we
aim to answer how securely we can estimate the true uncontaminated
star-planet radius ratio when the light curve may contain
contamination from unresolved light sources inside the photometry
aperture when combining multicolour transit observations with a
physics-based contamination model in a Bayesian parameter estimation
setting. More generally, we study how the contamination level, colour
differences between the planet host and contaminant stars, transit
signal-to-noise ratio, and available prior information affect the
contamination and true radius ratio estimates.
The study is based on simulations and ground-based multicolour transit
observations. The contamination analyses were carried out with a
contamination model integrated into the PYTRANSIT V2 transit
modelling package, and the observations were carried out with the
MuSCAT2 multicolour imager installed in the 1.5m Telescopio Carlos
Sanchez in the Teide Observatory, in Tenerife.
We show that multicolour transit photometry can be used to estimate
the amount of flux contamination and the true radius ratio. Combining
the true radius ratio with an estimate for the stellar radius yields
the true absolute radius of the transiting object, which is a valuable
quantity in statistical candidate validation, and enough in itself to
validate a candidate whose radius falls below the theoretical lower
limit for a brown dwarf.
Description:
The light curves were observed with MuSCAT2 multicolour imager in g,
r, i, and, z passbands.
Objects:
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RA (2000) DE Designation(s)
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06 30 32.80 +29 40 20.3 WASP-12b = WASP-12b
10 19 38.01 -09 48 22.6 WASP-43b = WASP-43b
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 67 6 List of observation dates
wasp43b/* . 12 Individual light curves of WASP-43b
wasp12b/* . 12 Individual light curves of WASP-12b
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See also:
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)
J/A+A/588/L6 : WASP-12 transit light curves (Maciejewski+ 2016)
J/A+A/628/A115 : WASP-12, CoRoT-1 and TrES-3 light curves (von Essen+, 2019)
J/ApJ/720/872 : A spectropolarimetric analysis of WASP-12 (Fossati+, 2010)
J/A+A/563/A40 : WASP-43b g'r'i'z'JHK light curves (Chen+, 2014)
Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Name Star name
10- 11 I2 h RAh Right ascension (J2000)
13- 14 I2 min RAm Right ascension (J2000)
16- 20 F5.2 s RAs Right ascension (J2000)
22 A1 --- DE- Declination sign (J2000)
23- 24 I2 deg DEd Declination (J2000)
26- 27 I2 arcmin DEm Declination (J2000)
29- 32 F4.1 arcsec DEs Declination (J2000)
34- 43 A10 "date" Obs.date Observaiton date
45- 67 A23 --- Filename Begining of the file names with griz
light curve data
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Byte-by-byte Description of file: wasp12b/*
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Bytes Format Units Label Explanations
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1- 18 F18.10 d Time Exposuse mid-time (in BJD_TDB)
20- 37 F18.16 --- Flux Normalized detrended flux
39- 60 F22.19 --- Baseline Fitted baseline model
62- 79 F18.16 --- Model Model
81- 83 F3.1 --- Intercept Intercept
85-102 F18.12 d MJD MJD
104-121 F18.14 --- Sky Sky level
123-140 F18.16 --- Airmass Airmass
142-164 F23.19 --- Xshift X shift
166-188 F23.19 --- Yshift Y shift
190-207 F18.16 --- Entropy Aperture entropy
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Byte-by-byte Description of file: wasp43b/*
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.10 d Time Exposuse mid-time (in BJD_TDB)
20- 37 F18.16 --- Flux Normalized detrended flux
39- 56 F18.16 --- FluxRel Relative flux
58- 77 F20.18 --- FluxTrg Target flux
79- 98 F20.18 --- FluxRef Sum of reference star fluxes
100-117 F18.16 --- Baseline Fitted baseline model
119-136 F18.16 --- Model Model
138-140 F3.1 --- Intercept Intercept
142-164 E23.17 --- Sky Sky level
166-188 E23.20 --- Xshift X shift
190-212 E23.20 --- Yshift Y shift
214-236 E23.20 --- Entropy Aperture entropy
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Acknowledgements:
Hannu Parviainen, hannu(at)iac.es
(End) Patricia Vannier [CDS] 28-Aug-2019