J/A+A/690/A159 55 Cnc e JWST light curves and spectra (Patel+, 2024)
JWST reveals a rapid and strong day side variability of 55 Cancri e.
Patel J.A., Brandeker A., Kitzmann D., Petit dit de la Roche D.J.M.,
Bello-Arufe A., Heng K., Meier Valdes E., Persson C.M., Zhang M.,
Demory B.-O., Bourrier V., Deline A., Ehrenreich D., Fridlund M., Hu R.,
Lendl M., Oza A.V., Alibert Y., Hooton M.J.
<Astron. Astrophys. 690, A159 (2024)>
=2024A&A...690A.159P 2024A&A...690A.159P (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Photometry ;
Spectra, infrared
Keywords: techniques: spectroscopic - techniques: photometric -
planets and satellites: atmospheres -
planets and satellites: terrestrial planets -
planets and satellites: individual: 55 Cnc e
Abstract:
The nature of the close-in rocky planet 55 Cnc e is puzzling despite
having been observed extensively. Its optical and infrared occultation
depths show temporal variability, in addition to a phase curve
variability observed in the optical.
We wish to explore the possibility that the variability originates
from the planet being in a 3:2 spin-orbit resonance, thus showing
different sides during occultations. We proposed and were awarded
Cycle 1 time at the James Webb Space Telescope (JWST) to test this
hypothesis.
JWST/NIRCam (Near Infrared Camera) observed five occultations
(secondary eclipses), of which four were observed within a week, of
the planet simultaneously at 2.1 and 4.5um. While the former gives
band-integrated photometry, the latter provides a spectrum between
3.9-5.0um.
We find that the occultation depths in both bandpasses are highly
variable and change between a non-detection (-5±6ppm and 7±9ppm)
to 96±8ppm and 119+34-19ppm at 2.1um and 4.5um, respectively.
Interestingly, the variations in both bandpasses are not correlated
and do not support the 3:2 spin-orbit resonance explanation. The
measured brightness temperature at 4.5um varies between 873-2256K and
is lower than the expected dayside temperature of bare rock with no
heat re-distribution (2500K) which is indicative of an atmosphere. Our
atmospheric retrieval analysis of occultation depth spectra at 4.5um
finds that different visits statistically favour various atmospheric
scenarios including a thin outgassed CO/CO2 atmosphere and a silicate
rock vapour atmosphere. Some visits even support a flat line model.
The observed variability could be explained by stochastic outgassing
of CO/CO2, which is also hinted by retrievals. Alternatively, the
variability, observed at both 2.1 and 4.5um, could be the result of a
circumstellar patchy dust torus generated by volcanism on the planet.
Description:
Raw photometric (for 2.1um short-wave SW channel) and white-light
(for 4.5um long-wave LW channel) light curves for all visits of
55 Cnc e observed by NIRCam/JWST. Occultation depths spectra for all
visits observed by NIRCam/JWST.
Spectra is provided for four reduction methods. HANSOLO and SPARTA
reduction method provide absolute occultation depths while the other
methods provide relative occultation depths.
Objects:
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RA (2000) DE Designation(s)
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08 52 35.24 +28 19 47.34 55 Cancri = TOI-1773
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablee1.dat 50 169428 Raw photometric (for 2.1um short-wave SW channel)
and white-light (for 4.5um long-wave LW channel)
light curves for all visits of 55 Cnc e
observed by NIRCam/JWST (Fig. 1)
tablee2.dat 100 6160 Occultation depths spectra for all visits
observed by NIRCam/JWST (Fig. 3)
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See also:
J/A+A/533/A114 : Transit of super-Earth 55 Cnc e (Demory+, 2011)
J/A+A/539/A28 : New transit photometry for super-Earth 55 Cnc e (Gillon+ 2012)
J/A+A/545/A97 : 0.8-6µm calibrated spectrum of 55 Cnc (Crossfield, 2012)
J/ApJ/778/132 : C and O abundances in 55 Cnc (Teske+, 2013)
J/ApJ/792/L31 : HARPS & HARPS-N 55 Cnc radial velocities (Lopez-Morales+ 2014)
J/A+A/615/A117 : 55 Cnc geocoronal emission lines template (Bourrier+, 2018)
J/A+A/619/A1 : 55 Cnc radial velocities and photometry (Bourrier+, 2018)
J/A+A/653/A173 : CHEOPS 55 Cnc light curve (Morris+, 2021)
J/A+A/677/A112 : CHEOPS observations of 55 Cnc e (Meier Valdes+, 2023)
Byte-by-byte Description of file: tablee1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 18 F18.10 d Time Time (BJD)
20- 31 F12.10 --- Flux Normalised raw flux
33- 44 F12.10 --- e_Flux 1-sigma uncertainty in flux
46- 47 A2 --- Visit Visit (V1-V5) (Gi)
49- 50 A2 --- Channel [LW SW] Channel (2)
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Note (2): Channels as follows:
SW = 2.1um short-wave
LW = 4.5um long-wave
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Byte-by-byte Description of file: tablee2.dat
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Bytes Format Units Label Explanations
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1- 18 F18.16 um lambda [3.86/4.98] Wavelength
20- 43 E24.17 --- Fp Occultation depth
45- 66 E22.17 --- E_Fp Upper 68 credible interval of Fp
68- 89 E22.17 --- e_Fp Lower 68 credible interval of Fp
91- 92 A2 --- Visit Visit (V1-V5) (G1)
94-100 A7 --- Method Reduction method
(Eureka, HANSOLO, SPARTA or stark)
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Globla notes:
Note (G1): Visits as follows:
V1 = 2022-11-18 14:40:17/2022-11-18 19:15:53
V2 = 2022-11-20 19:43:08/2022-11-21 00:18:44
V3 = 2022-11-23 00:43:57/2022-11-23 05:19:33
V4 = 2022-11-24 11:38:15/2022-11-24 17:28:41
V5 = 2023-04-24 11:57:03/2023-04-24 16:32:36
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Acknowledgements:
Jayshil A. Patel, jayshil.patel(at)astro.su.se
(End) Patricia Vannier [CDS] 31-Jul-2024