Overview
- Researchers obtained the deepest spectrum yet of a little red dot using 30 hours of JWST data that, aided by gravitational lensing, yielded the equivalent of roughly 80 hours and revealed more than 40 spectral lines.
- The spectrum shows hydrogen, oxygen and helium features plus an 'iron forest' of about 16 iron lines and signs of electron scattering that together point to a powerful central high‑energy source embedded in dense, partially ionized gas.
- The team interprets GLIMPSE‑17775 as a black‑hole star: a rapidly accreting supermassive black hole enshrouded by a thick gas cocoon that reprocesses emitted light and can hide X‑ray emission.
- GLIMPSE‑17775 lies behind the galaxy cluster Abell S1063 and has a measured redshift of 3.5, with combined Webb and Hubble imaging indicating the source sits inside a relatively large host galaxy.
- Authors publish the result in The Astrophysical Journal and stress that targeted follow‑up on other little red dots with JWST, large ground telescopes, and deeper X‑ray searches is needed to test how common the black‑hole star scenario is.