J/A+A/616/A145 GTC transit light curves of WASP-127b (Chen+, 2018)
The GTC exoplanet transit spectroscopy survey.
IX. Detection of haze, Na, K, and Li in the super-Neptune WASP-127b.
Chen G., Palle E., Welbanks L., Prieto-Arranz J., Madhusudhan N.,
Gandhi S., Casasayas-Barris N., Murgas F., Nortmann L., Crouzet N.,
Parviainen H., Gandolfi D.
<Astron. Astrophys. 616, A145 (2018)>
=2018A&A...616A.145C 2018A&A...616A.145C (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Planets ; Spectroscopy
Keywords: planetary systems - planets and satellites: individual: WASP-127b -
planets and satellites: atmospheres - techniques: spectroscopic
Abstract:
Exoplanets with relatively clear atmospheres are prime targets for
detailed studies of chemical compositions and abundances in their
atmospheres. Alkali metals have been long suggested to exhibit broad
wings due to pressure broadening, but most of the alkali detections
only show very narrow absorption cores, probably due to the presence
of clouds. Here we report the strong detection of the
pressure-broadened spectral profiles of Na, K, and Li absorption in
the atmosphere of the super-Neptune WASP-127b, at 5.0σ,
4.1σ, and 3.4σ, respectively. We performed a spectral
retrieval modeling on the high-quality optical transmission spectrum
newly acquired with the 10.4m Gran Telescopio Canarias (GTC), in
combination with the re-analyzed optical transmission spectrum
obtained with the 2.5m Nordic Optical Telescope (NOT). By assuming a
patchy cloudy model, we retrieved the abundances of Na, K, and Li,
which are super-solar at 3.7σ for K and 5.1σ for Li (and
only 1.8σ for Na). We constrained the presence of haze coverage
to be around 52%. We also found a hint of water absorption, but cannot
constrain it with the global retrieval due to larger uncertainties in
the probed wavelengths. WASP-127b will be extremely valuable for
atmospheric characterization in the era of James Webb space telescope.
Description:
We provide here the transit light curves of the super-Neptune
WASP-127b obtained on the night of 2018/01/19 using the OSIRIS
instrument at the 10.4-m GTC telescope. The data were obtained by
using OSIRIS through a 40-arcsec broad slit with the R1000R grism. The
white-color light curve covers the wavelength range of 535-908nm, with
755-768nm being excluded. The spectroscopic light curves contain 75
channels of 5nm, and 10 channels of 10nm. We provide several auxiliary
parameters of the observations, some of which we have used to correct
the data from correlated noise, including the position drift of the
stars on the CCD detector in spatial and dispersion direction, the
relative change in the FWHM of absorption line (dispersion FWHM),
seeing (spatial FWHM), air mass, and rotator angle.
Objects:
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RA (2000) DE Designation(s)
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10 42 14.08 -03 50 06.3 WASP-127 = 2MASS J10421407-0350062
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
gtc-spec.dat 31 1988 Out-of-transit average spectra of WASP-127 and
its reference star, shown in Figure 1
gtc-wlc.dat 96 739 WASP-127 GTC transit white light curve (2018/01/19)
listlc.dat 39 86 List of ligth curves for chanels 01 to 86
lc/* . 86 Individual WASP-127 GTC transit spectroscopic
light curve in each chanel (2018/01/19)
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See also:
J/A+A/563/A41 : WASP-43 OSIRIS transmission spectroscopy (Murgas+, 2014)
J/A+A/589/A62 : GTC transit light curves of CoRoT-29b (Palle+, 2016)
J/A+A/594/A65 : GTC transit light curves of HAT-P-32b (Nortmann+, 2016)
J/A+A/600/L11 : GTC transit light curves of WASP-52b (Chen+, 2017)
J/A+A/605/A114 : GTC transit light curves of WASP-48b (Murgas+, 2017)
Byte-by-byte Description of file: gtc-spec.dat
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Bytes Format Units Label Explanations
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1- 9 F9.4 nm Lambda Common wavelength grid
11- 20 F10.3 --- Flux-sci Spectrum of WASP-127 interpolated on common
wavelength grid, shown in Figure 1
(in ADU units)
22- 31 F10.3 --- Flux-ref Spectrum of the reference star interpolated
on common wavelength grid, shown in Figure 1
(in ADU units)
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Byte-by-byte Description of file: gtc-wlc.dat
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Bytes Format Units Label Explanations
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1- 15 F15.7 d BJD Barycentric Julian Date (TDB standard)
17- 24 F8.6 --- Flux Relative flux
26- 33 F8.6 --- e_Flux Uncertainty of relative flux
35- 44 F10.6 pix posX Drift of star on CCD in spatial direction
46- 55 F10.6 pix posY Drift of star on CCD in dispersion direction
57- 65 F9.6 pix fwhmX Relative change of full width at half maximum
of the stellar absorption line profile
67- 75 F9.6 pix fwhmY Full width at half maximum of the stellar
spatial profile
77- 84 F8.6 --- Airm Airmass during observation
86- 96 F11.6 deg RotAng Rotator angle during observation
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Byte-by-byte Description of file: listlc.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- FileName Name of the file in subdirectory lc
14- 28 A15 nm Range Wavelength range
30- 39 A10 --- Obs.date Observation date (2018/01/19)
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
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1- 6 F6.1 nm lambda1 Wavelength of the left border of the channel
8- 13 F6.1 nm lambda2 Wavelength of the right border of the channel
15- 29 F15.7 d BJD Barycentric Julian Date (TDB standard)
31- 38 F8.6 --- Flux Relative flux
40- 47 F8.6 --- e_Flux Uncertainty of relative flux
49- 58 F10.6 pix posX Drift of star on CCD in spatial direction
60- 69 F10.6 pix posY Drift of star on CCD in dispersion direction
71- 79 F9.6 pix fwhmX Relative change of full width at half maximum
of the stellar absorption line profile
81- 89 F9.6 pix fwhmY Full width at half maximum of the stellar
spatial profile
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Acknowledgements:
Guo Chen, gchen(at)iac.es
References:
Murgas et al., Paper I 2014A&A...563A..41M 2014A&A...563A..41M, Cat. J/A+A/563/A41
Parviainen et al., Paper II 2016A&A...585A.114P 2016A&A...585A.114P
Palle et al., Paper III 2016A&A...589A..62P 2016A&A...589A..62P, Cat. J/A+A/589/A62
Nortmann et al., Paper IV 2016A&A...594A..65N 2016A&A...594A..65N, Cat. J/A+A/594/A65
Chen et al., Paper V 2017A&A...600A.138C 2017A&A...600A.138C
Chen et al., Paper VI 2017A&A...600L..11C 2017A&A...600L..11C, Cat. J/A+A/600/L11
Murgas et al., Paper VII 2017A&A...605A.114M 2017A&A...605A.114M, Cat. J/A+A/605/A114
Parviainen et al., Paper VIII 2018A&A...609A..33P 2018A&A...609A..33P
(End) Guo Chen [IAC], Patricia Vannier [CDS] 24-May-2018