TY - JOUR
T1 - JWST/MIRI observations of the young TWA 27 system
T2 - Hydrocarbon disk chemistry, silicate clouds, and evidence of a circumplanetary disk
AU - Patapis, P.
AU - Morales-Calderón, M.
AU - Arabhavi, A. M.
AU - Kühnle, H.
AU - Gasman, D.
AU - Cugno, G.
AU - Mollière, P.
AU - Matthews, E.
AU - Mâlin, M.
AU - Whiteford, N.
AU - Lagage, P. O.
AU - Waters, R.
AU - Guedel, M.
AU - Henning, Th
AU - Vandenbussche, B.
AU - Absil, O.
AU - Argyriou, I.
AU - Barrado, D.
AU - Baudoz, P.
AU - Boccaletti, A.
AU - Bouwman, J.
AU - Cossou, C.
AU - Coulais, A.
AU - Decin, L.
AU - Gastaud, R.
AU - Glasse, A.
AU - Glauser, A. M.
AU - Grant, S.
AU - Min, M.
AU - Kamp, I.
AU - Olofsson, G.
AU - Pye, J.
AU - Rouan, D.
AU - Royer, P.
AU - Scheithauer, S.
AU - Sun, X.
AU - Tremblin, P.
AU - Colina, L.
AU - Ray, T. P.
AU - Östlin, G.
AU - Van Dishoeck, E. F.
AU - Wright, G.
N1 - Publisher Copyright:
© The Authors 2025.
PY - 2025/11/28
Y1 - 2025/11/28
N2 - Context. The Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope (JWST) enables the characterisation of young self-luminous gas giants in a previously inaccessible wavelength range, revealing insights into physical processes of the gas, dust, and clouds. Aims. We aim to characterise the young planetary system TWA 27 (2M1207) in the mid-infrared, revealing the atmosphere and disk spectra of the M9 brown dwarf TWA 27A and its L6 planetary-mass companion TWA 27b. Methods. We obtained data from the MIRI Medium Resolution Spectrometer (MRS) from 4.9 to 20 μm, and MIRI Imaging in the F1000W and F1500W filters. We applied high-contrast imaging data processing methods in order to extract the companion spectral energy distribution up to 15 μm at a separation of 0.″78 and contrast of 60. Using published spectra from JWST/NIRSpec, we analysed the 1-20 μm spectra with self-consistent atmosphere grids, and the molecular disk emission from TWA 27A with 0D slab models. Results. We find that the atmosphere of TWA 27A is well fitted with the BT-SETTL model of effective temperature T eff ~ 2780 K, logg ~ 4.3, and a blackbody component of ∼740 K for the circumstellar disk inner rim. The disk consists of at least 11 organic molecules, and neither water nor silicate dust emission are detected. The atmosphere of the planet TWA 27b matches with a T eff ~ 1400 K low-gravity model when adding extinction, with the ExoREM grid fitting the best. MIRI spectra and photometry for TWA 27b reveal a silicate cloud absorption feature between 8-10 μm, and evidence (>5σ) of infrared excess at 15 μm that is consistent with predictions from circumplanetary disk emission. Conclusions. The MIRI observations present novel insights into the young planetary system TWA 27, showing a diversity of features that can be studied to understand the formation and evolution of circumplanetary disks and young dusty atmospheres.
AB - Context. The Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope (JWST) enables the characterisation of young self-luminous gas giants in a previously inaccessible wavelength range, revealing insights into physical processes of the gas, dust, and clouds. Aims. We aim to characterise the young planetary system TWA 27 (2M1207) in the mid-infrared, revealing the atmosphere and disk spectra of the M9 brown dwarf TWA 27A and its L6 planetary-mass companion TWA 27b. Methods. We obtained data from the MIRI Medium Resolution Spectrometer (MRS) from 4.9 to 20 μm, and MIRI Imaging in the F1000W and F1500W filters. We applied high-contrast imaging data processing methods in order to extract the companion spectral energy distribution up to 15 μm at a separation of 0.″78 and contrast of 60. Using published spectra from JWST/NIRSpec, we analysed the 1-20 μm spectra with self-consistent atmosphere grids, and the molecular disk emission from TWA 27A with 0D slab models. Results. We find that the atmosphere of TWA 27A is well fitted with the BT-SETTL model of effective temperature T eff ~ 2780 K, logg ~ 4.3, and a blackbody component of ∼740 K for the circumstellar disk inner rim. The disk consists of at least 11 organic molecules, and neither water nor silicate dust emission are detected. The atmosphere of the planet TWA 27b matches with a T eff ~ 1400 K low-gravity model when adding extinction, with the ExoREM grid fitting the best. MIRI spectra and photometry for TWA 27b reveal a silicate cloud absorption feature between 8-10 μm, and evidence (>5σ) of infrared excess at 15 μm that is consistent with predictions from circumplanetary disk emission. Conclusions. The MIRI observations present novel insights into the young planetary system TWA 27, showing a diversity of features that can be studied to understand the formation and evolution of circumplanetary disks and young dusty atmospheres.
KW - methods: data analysis
KW - planets and satellites: atmospheres
KW - planets and satellites: formation
KW - planets and satellites: gaseous planets
KW - protoplanetary disks
KW - techniques: spectroscopic
UR - https://www.scopus.com/pages/publications/105023581537
UR - https://ui.adsabs.harvard.edu/abs/2025A%26A...704A...5P/abstract
U2 - 10.1051/0004-6361/202556296
DO - 10.1051/0004-6361/202556296
M3 - Article
AN - SCOPUS:105023581537
SN - 0004-6361
VL - 704
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A5
ER -