First Stars Found: Webb Peers into the Universe's Childhood ⚡ экспресс
Gravitationally lensed by the MACS J0416 cluster, the Population III star candidate LAP1-B (z=6.6) is the first object matching three theoretical predictions: formation in low-metallicity halos with T_vir~10^3–10^4 K, a top-heavy mass function, and low-mass clusters (~several ×10^3 M_⊙) of massive Pop III stars. The object is consistent with young stars in a ~5×10^7 M_⊙ dark matter halo that have partially enriched the surrounding gas. The semi-analytical model of Visbal et al. (2020) yields roughly one such source in the MACS J0416 field at z=6–7. At higher z the numbers are greater, but increased photometric distance and lower halo masses with stars hinder detection. Thus, LAP1-B is found at the theoretically expected redshift for current observational capabilities.
The space telescope James Webb has for the first time caught light from stars of pure hydrogen and helium — just what the very first stars after the Big Bang are believed to have been made of. A giant cluster of galaxies MACS J0416 helped to see them: its gravity acted as a cosmic magnifying glass, amplifying the faint glimmer of the distant galaxy LAP1-B.
The newborn stars inside it fit theoretical predictions perfectly. They arise in tiny clumps of dark matter — the invisible framework of the cosmos. Each star is a true heavyweight, a hundred times more massive than the Sun, while the whole cluster weighs in at only a couple of thousand solar masses. Some of them have already exploded as supernovae, enriching the surrounding gas with heavier elements.
Here's the twist: the very, very first stars ignited even earlier, but their light is so faint that even Webb couldn't spot them. LAP1-B isn't the absolute beginning, but a rare chance to see an almost pristine past. According to calculations, only one such object appears in the entire sky.
🎯 The gas temperature in the 'cradles' of these stars was lower than in a pizza oven — just about a thousand degrees, which by cosmic standards is very cold.