Yuki Isobe

The galaxy CEERS2-588 flared up like a bonfire fed with an armful of wood all at once. Just 400 million years after the Big Bang, it had already built up a mass of a billion suns and ignited countless stars. But then the fuel ran out, and over the last 10 million years, star formation in it has almost completely ceased.

400 million years after the Big Bang, the James Webb Space Telescope noticed a bright spot near the galaxy GN-z11 — like a distant lighthouse whose light pushed through the primordial darkness.

Imagine an ancient manuscript, where a new story is written over an old text. Over time, the upper layer wears thin, and lines of the past show through. That’s exactly how globular clusters, the oldest stellar systems in the Universe, are structured, like a palimpsest.

For thirteen billion years, light battled through cosmic emptiness. It bent around massive galaxy clusters that, as Einstein predicted, acted as giant lenses — amplifying and distorting the distant glow. In 2023, the NIRSpec instrument on the James Webb Space Telescope captured this light and spread it into spectra.