Astronomers Spot "First Stars" Billions of Years After They Were Supposed to Die
2 days ago
- #astronomy
- #PopIIIstars
- #cosmology
- A galaxy named MPG-CR3 (CR3) was discovered, appearing to be 'metal-free' and possibly containing first-generation (Pop III) stars.
- Pop III stars are the first generation of stars, formed early in the universe's history, with no elements heavier than hydrogen and helium.
- The galaxy was found about 2 billion years after the Epoch of Reionization, much later than expected for Pop III stars.
- Data from telescopes like JWST, VLT, and Subaru showed CR3 has clean hydrogen and helium lines and almost no metals, with metallicity at 0.7% of the Sun's.
- CR3 is relatively young (about 2 million years old), dust-free, and has small stars, unusual for an ancient galaxy.
- The missing Helium II (He II) emission line, a key indicator of Pop III stars, might be due to interference or signal decay.
- CR3's isolation in an 'underdense region' of space may explain its late formation of pristine stars, avoiding metal pollution from nearby stars.
- Confirmation of CR3 as a Pop III galaxy would be a major scientific breakthrough, making these stars easier to study.