2025ApJ...995..149P

We report the discovery of a debris disk surrounding the M3 star TWA 20, revealed by JWST coronagraphic observations using the Near Infrared Camera. With reference differential imaging (RDI), we resolve the disk in scattered light in the F200W filter at a high signal-to-noise ratio and in the F444W filter at a low signal-to-noise ratio. The disk morphology and orientation are characterized via a forward-modeling approach, where we determine a radius of 64.7${}_{-6.5}^{+6.2}$ au and an inclination of 70.1${}_{-3.3}^{+2.5}$ degrees. Utilizing our forward model, we improve the fidelity of the debris disk image using model-constrained RDI. The newly discovered disk is one of only six disks detected in scattered light that orbit M dwarf stars; it is the third largest of the six resolved M dwarf disks and orbits the third faintest host star. The detection of this disk exemplifies the sensitivity of JWST to debris disks around low-luminosity host stars, which have historically been difficult to detect because these disks are cool and dim. We identify a nebulous structure that cannot be explained by an axisymmetric disk. A search for companions in the TWA 20 system yields no candidates.