The James Webb Space Telescope (JWST) has revealed a bright galaxy called GHZ8 that is located 13.4 billion light‑years away, at a redshift of 10.23. The galaxy shines in the ultraviolet (UV), suggesting a rapid buildup of stars in the early Universe.

Using JWST’s Mid‑Infrared Instrument (MIRI) in low‑resolution spectroscopic mode, scientists detected the Hβ–[O III] emission complex at a significance of about 5 σ and the Hα line at about 4 σ. The measured fluxes are 3.2 ± 0.9 × 10⁻¹⁸ erg s⁻¹ cm⁻² for the Hβ–[O III] blend and 1.7 ± 0.4 × 10⁻¹⁸ erg s⁻¹ cm⁻² for Hα.

High‑resolution images from JWST’s Near‑Infrared Camera (NIRCam) show that GHZ8 actually contains two separate clumps. The brighter, extended part (GHZ8‑main) and a fainter, compact southeastern component (GHZ8‑SE) are separated by only 0.16 arcseconds, which corresponds to about 600 parsecs. Their intrinsic UV absolute magnitudes are –19.91 ± 0.10 mag for GHZ8‑main and –18.03 ± 0.15 mag for GHZ8‑SE.

The two clumps both display very blue UV slopes (βUV ≈ –2.5 for the main component and –3.4 for the southeastern clump), indicating that each hosts a very young stellar population. The close proximity and the intense star‑forming signatures suggest that GHZ8 may be experiencing a merger‑induced burst of star formation, although the current data are not sufficient to confirm this scenario without deeper imaging or spatially resolved kinematic studies.