Coronagraphic JWST/NIRCam Images of the 49 Ceti Debris Disk

Debris disks host a variety of morphologies and compositions including asymmetries, CO molecular gas, and dense planetestimal belts sculpted by planets. However, some systems, such as HD 61005 (the “Moth”), reveal a secondary component, a swept back outer disk, likely resulting from interactions with the local interstellar medium. 49 Ceti is a young A-type star located 57 pc away with an age of ~40 Myr. Previous observations reveal a dense planetestimal belt, strong CO molecular gas, and no reported planet detections. We present here the first coronagraphic JWST/NIRCam (F200W, F444W) images of the 49 Ceti debris disk out to ~4.0” (236 au). With these observations, we detect the dense planetestimal belt; however, we also detect, in both bands, an extended fan of material along the southwest minor axis out to 118 au, not seen in previous ground-based observations. This diffuse scattered light imagery is similar to that seen in HD 61005. We therefore conduct disk modeling to constrain the disk grain properties, including the grain size and composition. With these models, we explore different scenarios to understand this diffuse morphology, including interstellar medium interactions, sculpting by planets, and recent collisions.