Author ORCID Identifier

Nathaniel Kerman: 0009-0003-5115-3832

Kimberly Ward-Duong: 0000-0002-4479-8291

Mickaël Bonnefoy: 0000-0001-8260-880X

Nicole Arulanantham: 0000-0003-2631-5265

Benoît Tabone: 0000-0002-1103-3225

Catherine Dougados: 0000-0001-6660-936X

Mathilde Mâlin: 0000-0002-2918-8479

Claire Finley: 0000-0002-9884-9584

Document Type

Article

Publication Date

6-2026

Publication Title

The 23rd Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun

Abstract

SR 12 c, a planetary mass companion in a ~1000 au orbit around its binary host, is one of only three planetary mass objects surrounded by an ALMA-detected circumplanetary disk (CPD). CPDs with different masses and orbits provide crucial laboratories to study substellar formation: the structure and mass of CPDs govern planet formation timescales and may distinguish between formation mechanisms, while dust composition and grain sizes ultimately affect atmospheric metallicity and satellites. CPD properties can also be compared against better-understood brown dwarf and low-mass star disks to test how disk properties scale with central object mass at the low-mass extreme. Spitzer-era studies of disks around brown dwarfs and stars revealed crystalline and amorphous silicates and grain growth to mm sizes. Extending disk characterization to objects of planetary mass requires measurements in the mid-infrared and mm ranges only possible in the era of overlapping ALMA and JWST observations. We present mid-infrared integral field unit observations of SR 12 c and its CPD using JWST/MIRI-MRS. Our observations reveal the SR 12 system embedded within the ρ Oph cloud complex, which adds bright, structured emission with strong H2 rotational lines. We first spatially model and subtract this nebular background before extracting a 5-28 µm spectrum of SR 12 c. We combine this MIRI spectrum with literature photometry and spectroscopy to form a spectral energy distribution (SED) spanning from UV to mm wavelengths. Finally, we present SED modeling using radiative transfer and retrieval codes (MCFOST, DuCKLinG) which explore various disk geometries and multi-temperature components. Preliminary models suggest that SR 12 c’s dust disk has a midplane temperature of ~60 K and surface temperature of ~50-80 K. We discuss implications for this planetary mass companion’s disk size, structure, and composition in the context of the well-characterized landscape of disks around brown dwarfs and stars.

Version

Version of Record

Download

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.