James Webb Space Telescope Feed Post

Arxiv: Unveiling the HD 95086 system at mid-infrared wavelengths with JWST/MIRI Published: 8/29/2024 9:19:43 PM Updated: 11/14/2024 9:48:10 PM

Paper abstract: Mid-infrared imaging of exoplanets and disks is now possible with thecoronagraphs of the MIRI on the JWST. This wavelength range unveils newfeatures of young directly imaged systems and allows us to obtain newconstraints for characterizing the atmosphere of young giant exoplanets andassociated disks. These observations aim to characterize the atmosphere of theplanet HD 95086 b by adding mid-infrared information so that the varioushypotheses about its atmospheric parameters values can be unraveled. Improvedimages of circumstellar disks are provided. We present the MIRI coronagraphicimaging of the system HD 95086 obtained with the F1065C, F1140, and F2300Cfilters at central wavelengths of 10.575, 11.3, and 23 microns, respectively.We explored the method for subtracting the stellar diffraction pattern in theparticular case when bright dust emitting at short separation is present.Furthermore, we compared different methods for extracting the photometry of theplanet. Using the atmospheric models Exo-REM and ATMO, we measured theatmospheric parameters of HD 95086 b. The planet HD 95086 b and thecontribution from the inner disk are detected at the two shortest MIRIwavelengths F1065C and F1140C. The outer colder belt is imaged at 23 microns.The mid-infrared photometry provides better constraints on the atmosphericparameters. We evaluate a temperature of 800-1050 K, consistent with oneprevious hypothesis that only used NIR data. The radius measurement of 1.0-1.14RJup is better aligned with evolutionary models, but still smaller thanpredicted. These observations allow us to refute the hypothesis of a warmcircumplanetary disk. HD 95086 is one of the first exoplanetary systems to berevealed at mid-infrared wavelengths. This highlights the interests andchallenges of observations at these wavelengths.