JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462

We present JWST/NIRCam F187N, F200W, F405N and F410M direct imaging data of the disk surrounding SAO 206462. Previous images show a very structured disk, with a pair of spiral arms thought to be launched by one or more external perturbers. The spiral features are visible in three of the four filters, with the non-detection in F410M due to the large detector saturation radius. We detect with a signal-to-noise ratio of 4.4 a companion candidate (CC1) that, if on a coplanar circular orbit, would orbit SAO 206462 at a separation of $\sim300$ au, $2.25\sigma$ away from the predicted separation for the driver of the eastern spiral. According to the BEX models, CC1 has a mass of $M_\mathrm{CC1}=0.8\pm0.3~M_\mathrm{J}$. No other companion candidates were detected. At the location predicted by simulations of both spirals generated by a single massive companion, the NIRCam data exclude objects more massive than $\sim2.2~M_\mathrm{J}$ assuming the BEX evolutionary models. In terms of temperatures, the data are sensitive to objects with $T_{\text{eff}}\sim650-850$ K, when assuming planets emit like blackbodies ($R_\mathrm{p}$ between 1 and $3 R_\mathrm{J}$). From these results, we conclude that if the spirals are driven by gas giants, these must be either cold or embedded in circumplanetary material. In addition, the NIRCam data provide tight constraints on ongoing accretion processes. In the low extinction scenario we are sensitive to mass accretion rates of the order $\dot{M}\sim10^{-9} M_\mathrm{J}$ yr$^{-1}$. Thanks to the longer wavelengths used to search for emission lines, we reach unprecedented sensitivities to processes with $\dot{M}\sim10^{-7} M_\mathrm{J}$ yr$^{-1}$ even towards highly extincted environments ($A_\mathrm{V}\approx50$~mag).Comment: 18 pages, 8 figures, 3 table

JWST/NIRCam Imaging of Young Stellar Objects. II. Deep Constraints on Giant Planets and a Planet Candidate Outside of the Spiral Disk Around SAO 206462

We present JWST/NIRCam F187N, F200W, F405N, and F410M direct imaging data of the disk surrounding SAO 206462. Previous images show a very structured disk, with a pair of spiral arms thought to be launched by one or more external perturbers. The spiral features are visible in three of the four filters, with the nondetection in F410M due to the large detector saturation radius. We detect with a signal-to-noise ratio of 4.4 a companion candidate that, if on a coplanar circular orbit, would orbit SAO 206462 at a separation of ∼300 au, 2.25 σ away from the predicted separation for the driver of the eastern spiral. No other companion candidates were detected. At the location predicted by simulations of both spirals generated by a single massive companion, the NIRCam data exclude objects more massive than ∼2.2 M _J assuming the BEX evolutionary models. In terms of temperatures, the data are sensitive to objects with T _eff ∼ 650–850 K, when assuming planets emit like blackbodies ( R _p between 1 and 3 R _J ). From these results, we conclude that if the spirals are driven by gas giants, these must be either cold or embedded in circumplanetary material. In addition, the NIRCam data provide tight constraints on ongoing accretion processes. In the low extinction scenario we are sensitive to mass accretion rates of the order $\dot{M}\sim {10}^{-9}{M}_{{\rm{J}}}$ yr ^−1 . Thanks to the longer wavelengths used to search for emission lines, we reach unprecedented sensitivities to processes with $\dot{M}\sim {10}^{-7}{M}_{{\rm{J}}}$ yr ^−1 even toward highly extincted environments ( A _V ≈ 50 mag)

Studying the birth of exoplanetary systems with the Planet Formation Imager (PFI)

International audienceDespite recent advancements, many fundamental questions still surround the processes that are involved in planetary birth: Where in the protoplanetary disk do the planets form and how do they grow? What factors determine the final architecture of planetary systems? How are water and other volatiles delivered to the protoplanets and how does this affect the potential habitability of these worlds?As part of the "Planet Formation Imager" (PFI) project we develop the roadmap for a future infrared high-angular resolution imaging facility that aims to answer these questions by witnessing the planetary formation processes on the natural scales where the material is assembled, which is the Hill sphere of the forming planets. PFI will detect giant protoplanets on all stellocentric radii, image their interaction with the ambient disk material, and trace their dynamical evolution during the first 100 million years, thereby reveal the processes that determine the architecture of planetary systems.In this contribution we give an overview about the work of the PFI science and technical working group and present radiation-hydrodynamics simulations from which we derive preliminary specifications that guide the design of the facility. We will present a baseline PFI architecture that can achieve these goals, point at remaining technical challenges, and suggest activities today that will help make the Planet Formation Imager facility a reality