J/A+A/702/A4 kappa And JWST/MIRI images (Godoy+, 2025)
A JWST/MIRI view of kappa Andromedae b.
Refining its mass, age, and physical parameter.
Godoy N., Choquet E., Serabyn E., Malin M., Tremblin P., Danielski C.,
Lagage P.O., Boccaletti A., charnay B., Ressler M.E.
<Astron. Astrophys. 702, A4 (2025)>
=2025A&A...702A...4G 2025A&A...702A...4G (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Infrared
Keywords: techniques: high angular resolution -
planets and satellites: atmospheres -
planets and satellites: fundamental parameters -
planets and satellites: gaseous planets - infrared: planetary systems
Abstract:
kappa And b is a substellar companion with a mass near the
planet-brown dwarf boundary orbiting a B9IV star at ∼50-100au.
Estimates of its age and mass vary, which has fueled a decade-long
debate. Additionally, the atmospheric parameters (Teff 1650-2050K and
log(g) 3.5-5.5dex) remain poorly constrained. The differences in
atmospheric models and inhomogeneous datasets contribute to the varied
interpretations.
We aim to refine the characterization of kappa And b by using
mid-infrared data to capture its full bolometric emission. Combined
with near-infrared (NIR) measurements, we aim to constrain Teff,
log(g), and the radius to narrow down the uncertainties in age and
mass.
We obtained JWST/MIRI coronagraphic data in the F1065C, F1140C, and
F1550C filters and recalibrated existing NIR photometry using an
updated ATLAS stellar model. We used MIRI color-magnitude diagrams to
probe the likelihood of species (e.g., CH4, NH3, and silicates). We
compared the H and F1140C colors and magnitudes of the companion to
isochrones to constrain the age and mass. We then modeled its spectral
energy distribution with atmospheric models to refine the estimates of
Teff, radius, and log(g) and to constrain age and mass using
evolutionary models.
Cloudy atmosphere models fit the spectral energy distribution of kappa
And b best. This is consistent with its L0/L2 spectral type and its
position near silicate- atmosphere field objects in the MIRI
color-magnitude diagram. We derived an age of 47±7Myr and a mass of
17.3±1.8MJup by weight-mean combining the models. Atmospheric
modeling yielded Teff=1791±68K and a radius of 1.42±0.06RJup .
This improves the precision by ∼ 30% over previous estimates. Log(g)
was constrained to 4.35±0.07dex, which is an improvement in the
precision by ∼70% relative to the most precise literature value of
4.75±0.25 dex.
Our new mass estimate places kappa And b slightly above the
planet-brown dwarf boundary determined by the deuterium-burning limit.
Our age estimate is ∼75% more precise than previous values and aligns
the object with the Columba association (42Myr). The derived Teff
suggests silicate clouds, but this needs to be confirmed
spectroscopically. MIRI data were crucial to refine the radius and
temperature, which led to stronger constraints on the age and mass
(both dependent on the model) and improved the overall
characterization of kappa And b.
Description:
These data corresponds to several datasets used in some figures of the
paper. The data include the re-calibrated archive datasets, contrast
curves, sensitivity curves and maps, post-processed images.
Objects:
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RA (2000) DE Designation(s)
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23 40 24.50 +44 20 02.1 kappa And = TIC 176945734
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
cumjyrec.dat 74 22 Currie et al. (2018AJ....156..291C 2018AJ....156..291C)
re-calibrated data in mJy
curec.dat 74 22 Currie et al. (2018AJ....156..291C 2018AJ....156..291C)
re-calibrated data in erg/s/cm2/Å
himjyrec.dat 74 32 Hinkley et al. (2013ApJ...779..153H 2013ApJ...779..153H)
re-calibrated data in mJy
hirec.dat 74 32 Hinkley et al. (2013ApJ...779..153H 2013ApJ...779..153H)
re-calibrated data in erg/s/cm2/Å
stmjyrec.dat 74 35 Stone et al. (2020AJ....160..262S 2020AJ....160..262S)
re-calibrated data in mJy
strec.dat 74 35 Stone et al. (2020AJ....160..262S 2020AJ....160..262S)
re-calibrated data in erg/s/cm2/Å
wimjyrec.dat 74 1665 Wilcomb et al. (2020AJ....160..207W 2020AJ....160..207W)
re-calibrated data in mJy
wirec.dat 74 1665 Wilcomb et al. (2020AJ....160..207W 2020AJ....160..207W)
re-calibrated data in erg/s/cm2/Å
mag.dat 81 16 All magnitudes re-calibrated
contrast.dat 131 1506 Contrast curve for F1065C, F1140C and F1550C
atmo.dat 81 1292 Sensitivity curve in mass for F1065C, F1140C
and F1550C using ATMOceq
dusty.dat 81 1288 Sensitivity curve in mass for F1065C, F1140C
and F1550C using DUSTY-Linder2019
list.dat 184 9 List of fits images and maps
fits/* . 9 Individual fits images and maps
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See also:
J/AJ/160/207 : OSIRIS K-band spectroscopy of kappa And b (Wilcomb+, 2020)
Byte-by-byte Description of file: *mjyrec.dat
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Bytes Format Units Label Explanations
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1- 24 E24.19 um lambda Wavelength
26- 49 E24.19 mJy Flux Flux
51- 74 E24.19 mJy e_Flux Flux uncertainty
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Byte-by-byte Description of file: curec.dat hirec.dat strec.dat wirec.dat
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Bytes Format Units Label Explanations
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1- 24 E24.19 um lambda Wavelength
26- 49 E24.19 10mW/m2/nm Flux Flux (in erg/s/cm2/Å)
51- 74 E24.19 10mW/m2/nm e_Flux Flux uncertainty (in erg/s/cm2/Å)
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Byte-by-byte Description of file: mag.dat
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Bytes Format Units Label Explanations
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1- 26 A26 --- Filt Filter name
28- 33 F6.3 um lambda Cental filter wavelength
35- 40 F6.3 mag mag Magnitude in Filter (Vega_system)
42- 46 F5.3 mag e_mag Magnitude in Filter uncertainty (Vega_system)
48 I1 --- used [0/1] Used data
50- 61 A12 --- Paper Reference paper of the calibrated data (1)
63- 73 E11.6 10mW/m2/nm ZP ?=- Zero Point of each filter
(in erg/s/cm2/Å)
75- 81 F7.2 Jy ZPjy ?=- Zero Point of each filter (in Jy)
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Note (1): References as follows:
Carson2013 = Carson et al., 2013ApJ...763L..32C 2013ApJ...763L..32C
Bonnefoy2014 = Bonnefoy et al., 2014A&A...562A.111B 2014A&A...562A.111B
Currie2018 = Currie et al., 2018AJ....156..291C 2018AJ....156..291C
Kuhn2018 = Kuhn et al., 2018PASP..130c5001K 2018PASP..130c5001K
Uyama2020 = Uyama et al., 2020AJ....159...40U 2020AJ....159...40U
ThisWork = this work
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Byte-by-byte Description of file: contrast.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Filt [F1065C F1140C F1550C] Filter
8- 31 E24.29 arcsec Sep Angular separation
33- 56 E24.29 mag contrastorimag 5-sigma contrast in magnitudes - original
58- 81 E24.29 mag contrastsmomag 5-sigma contrast in magnitudes - smoothed
83-106 E24.29 --- contrastori 5-sigma contrast - original
108-131 E24.29 --- contrastsmo 5-sigma contrast - smoothed
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Byte-by-byte Description of file: atmo.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Filt [F1065C F1140C F1550C] Filter
8- 31 E24.19 arcsec Sep Angular separation
33- 56 E24.19 MJup Mass Sensitivity curve in mass
58- 81 E24.19 MJup e_Mass Uncertainty in the sensitivity curve in mass
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Byte-by-byte Description of file: dusty.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Filt [F1065C F1140C F1550C] Filter
8- 31 E24.19 arcsec Sep Angular separation
33- 56 E24.19 MJup Mass Sensitivity curve in mass
58- 81 E24.19 MJup e_Mass Uncertainty in the sensitivity curve in mass
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 31 I4 Kibyte size Size of FITS file
33-108 A76 --- FileName Name of FITS file, in subdirectory fits
110-184 A75 --- Title Title of the FITS file
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Acknowledgements:
From Nicolas Godoy, nicolas.godoy(at)lam.fr
This project is funded/Co-funded by the European Union (ERC, ESCAPE,
project No 101044152). Views and opinions expressed are however those
of the author(s) only and do not necessarily reflect those of the
European Union or the European Research Council Executive Agency. Nei-
ther the European Union nor the granting authority can be held
responsible for them. These observations are associated with program
#1241. This research has made use of computing facilities operated by
CeSAM (Centre de donnees Astrophysiques de Marseille) data center
at LAM (Laboratoire Astrophysique de Marseille), Marseille, France. We
thank T. Stolker for providing support us- ing the Species python
package. We thank the authors Carson et al., Hinkley et al., Bonnefoy
et al., Currie et al., Kuhn et al., Wilcomb et al., Stone et al., and
Uyama et al., for providing and/or publishing the observational data
used in this study. This work has made use of data from the European
Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia),
processed by the Gaia Data Processing and Analysis Consortium (DPAC,
https://www. cosmos.esa.int/web/gaia/dpac/consortium). Funding for the
DPAC has been provided by national institutions, in particular, the
institutions participating in the Gaia Multilateral Agreement. This
research has made use of the Span- ish Virtual Observatory
(https://svo.cab.inta-csic.es) project funded by
MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB- I00.
This publication makes use of VOSA, developed under the Spanish
Virtual Observatory (https://svo.cab.inta-csic.es) project funded by
MCIN/AEI/10.13039/501100011033/ through grant PID2020-112949GB-I00.
VOSA has been partially updated by using funding from the European
Union's Horizon 2020 Research and Innovation Programme, under Grant
Agreement No 776403 (EXOPLANETS-A). This publication makes use of data
products from the Two Micron All Sky Survey, which is a joint project
of the University of Massachusetts and the Infrared Processing and
Analysis Center/California Insti- tute of Technology, funded by the
National Aeronautics and Space Administra- tion and the National
Science Foundation. This publication makes use of data products from
the Wide-field Infrared Survey Explorer, which is a joint project of
the University of California, Los Angeles, and the Jet Propulsion
Labora- tory/California Institute of Technology, funded by the
National Aeronautics and Space Administration. This work has benefited
from The UltracoolSheet, main- tained by Will Best, Trent Dupuy,
Michael Liu, Rob Siverd, and Zhoujian Zhang, and developed from
compilations by Dupuy & Liu (2012, ApJS, 201, 19), Dupuy & Kraus
(2013, Science, 341, 1492), Liu et al. (2016, ApJ, 833, 96), Best et
al. (2018, ApJS, 234, 1), and Best et al. (2020b, AJ, in press). This
research has made use of the Washington Double Star Catalog maintained
at the U.S. Naval Observatory. M.M., A.B., P.-O.L. acknowledge funding
support by CNES.
(End) Patricia Vannier [CDS] 05-Sep-2025