A Long Time Ago in a Galaxy Far, Far Away: A Candidate z similar to 12 Galaxy in Early JWST CEERS Imaging

We report the discovery of a candidate galaxy with a photo -z of z similar to 12 in the first epoch of the James Webb Space Telescope (JWST) Cosmic Evolution Early Release Science Survey. Following conservative selection criteria, we identify a source with a robust zphot = 11.8(+0.3) (-0.2) (1 sigma uncertainty) with m(F200W) = 27.3 and > 7 sigma detections in five filters. The source is not detected at lambda < 1.4 mu m in deep imaging from both Hubble Space Telescope (HST) and JWST and has faint similar to 3 sigma detections in JWST F150W and HST F160W, which signal a Ly alpha break near the red edge of both filters, implying z similar to 12. This object (Maisie's Galaxy) exhibits F115W - F200W > 1.9 mag (2 sigma lower limit) with a blue continuum slope, resulting in 99.6% of the photo-z probability distribution function favoring z > 11. All data-quality images show no artifacts at the candidate's position, and independent analyses consistently find a strong preference for z > 11. Its colors are inconsistent with Galactic stars, and it is resolved (r(h) = 340 +/- 14 pc). Maisie's Galaxy has log M-*/M-?similar to 8.5 and is highly star-forming (log sSFR similar to -8.2 yr(-1)), with a blue rest-UV color (beta similar to -2.5) indicating little dust, though not extremely low metallicity. While the presence of this source is in tension with most predictions, it agrees with empirical extrapolations assuming UV luminosity functions that smoothly decline with increasing redshift. Should follow-up spectroscopy validate this redshift, our universe was already aglow with galaxies less than 400 Myr after the Big Bang.