A Star from Another Galaxy: The Most Pristine Relic of the Early Universe
Astronomers led by Alexander Ji discovered SDSS J0715−7334, the most metal-poor star ever found, originating from the Large Magellanic Cloud. Its composition suggests it formed from gas enriched by a single massive Population III supernova, revealing how early stars seeded the universe with heavy elements. This discovery provides a rare local glimpse into the universe’s first generations of stars.
Teaching a Neural Network to Predict the Birth of the First Stars
Sojun Ono and Kazuyuki Sugimura developed a neural network emulator to model how the first stars (Population III) formed. Their method uses DeepONets split across density ranges and a new timescale-based update to keep predictions stable. The emulator reproduces chemical and thermal evolution with high accuracy while running up to a thousand times faster than traditional simulations, making it a powerful tool for studying early star formation.
A New Look at the Earliest Stars: Understanding Population III Spectra
This study refines models of Population III (Pop III) stars, the first stars in the universe, using the GALSEVN framework. It confirms that strong helium emission can help identify Pop III stars but only within their first million years. The study also explores their role in cosmic reionization and predicts their impact on gravitational waves from binary black hole mergers. Future telescopes and detectors may soon provide evidence of these ancient stars.
Unveiling the First Stars: How Population III Stars Impact the 21cm Signal
Ventura et al. investigate how Population III stars influence the 21cm signal by using the meraxes semi-analytical model. They find that while Pop. III stars do not significantly alter reionization, their strong X-ray emissions heat the intergalactic medium at z ≥ 15, affecting the 21cm signal. Their simulations suggest that SKA1-low could detect these effects, potentially providing indirect evidence of the first stars in the universe.