HD1 is a galaxy-candidate identified in 2022, apparently with
a higher redshift of than any known galaxy, i.e., z = 13.27.
Both HD1 and another such candidate, HD2, were so-termed to
indicate they were identified for being H-banddropouts,
that indicate a Lyman-break galaxy (LBG) at that redshift.
Spectrography, which provides a more detailed
characterization, suggests both are in the z ~ 3 to 4 range.
HD1 and HD2 were discovered in COSMOS data.