First observations of brown dwarf candidates in globular clusters with JWST

Since the first detection of chemical anomalies in globular clusters nearly a century ago, the study of this puzzling phenomenon has been largely confined to the brightest post-main sequence members. The last two decades of Hubble Space Telescope observations have extended this analysis to fainter stars on the lower main sequence. Now, the unprecedented sensitivity of the James Webb Space Telescope (JWST) allows for an even longer mass baseline, reaching beyond the end of the main sequence and into the substellar regime.

In this talk, I will review recent developments in the search and characterization of brown dwarf candidates in nearby globular clusters, and discuss the preliminary constraints on the chemistry of these objects derived from new JWST photometry. While meeting the broad expectations of low-temperature models, these previously unseen members appear to be brighter and redder than anticipated, suggesting a possible enhancement in the carbon-to-oxygen ratio compared to both their main sequence and red giant siblings.