Methane T‐Dwarf Candidates in the Star Forming Region IC 348

IC 348 is a young (t∼3 Myr) and nearby (d∼340 pc) star forming region in the Perseus molecular cloud. We performed a deep imaging survey using the MEGACAM (z‐band) and WIRCAM (JHK and narrowband CH4 on/off) wide‐field cameras on the Canada‐France‐Hawaii Telescope. From the analysis of the narrowband CH4 on/off deep images, we report 4 T‐dwarf candidates, of which 3 clearly lie within the limits of the IC 348 cluster. An upper limit on the extinction was estimated for each candidate from colour‐magnitude diagrams, and found consistent with extinction maps of the cloud. Initial comparisons with T‐dwarf spectral models suggest these candidates have a spectral type between T3 and T5, and perhaps later, potentially making these among the lowest mass isolated objects detected in a young star forming region so far.