Storms are Brewing in the ONC A First Look at Variability Results from a Sample of Young Substellar Worlds.pdf

Atmospheric variability monitoring is one of our most powerful tools to provide insight into the structure of substellar atmospheres, but observations are often limited to individual targets, making it difficult to separate intrinsic atmospheric diversity from the confounding effects of age and metallicity. We address this longstanding challenge with JWST GO 8155, which observed over 50 low-mass stars and substellar objects in the Orion Nebula Cluster over 36 hours of simultaneous NIRCam F162 and F250 band observations at a one minute cadence. The co-eval, co-compositional nature of this cluster sample allows us to isolate atmospheric processes directly, probing the diversity of atmospheric phenomenon across a range of temperatures and and the Storms are Brewing in the ONC Collaboration masses. Our preliminary results reveal >36% of our sources to be variable. While most objects show similar light curve structure between the two filters, others appear to be 180° out of phase (potentially due to systamtics) or have sub-structure unique to one bandpass. The young ages of these substellar objects lead to longer rotation periods than the observational baseline, and as such our period estimates are poorly constrained.