Astronomers may have discovered Monster Stars from Cosmic Dawn
The James Webb Space Telescope may have spotted signs of the first stars to form in the universe. These stars were monsters, the likes of which have not been born since the infancy of the universe.
The James Webb Space Telescope has discovered compelling evidence of supermassive first stars in a galaxy designated as GS 3072. These stars contain between 1,000 and 10,000 times the mass of the Sun, and existed only in the very early universe. The discovery is backed by theoretical work that predicted that the first stars in the universe were formed in rare, turbulent streams of cold gas in the early universe, that could only exist less than a billion years after the Big Bang.
The discovery may have solved a long-standing mystery in cosmology, on how extraordinarily bright black holes could exist in the early universe. These first monster stars would have lived fast and died young, leaving behind chemical signatures that could be discovered billions of years later. These can be considered as cosmic fossils. The galaxy contains a nitrogen-to-oxygen ratio of 0.46 which is far higher than can be explained by any known type of star or stellar explosion.
The evolution of extremely massive stars
The researchers have modelled the evolution or stellar life cycles of stars containing between 1,000 and 10,000 solar masses, and discovered a process that can produce massive amounts of nitrogen. The cores fuse helium, producing carbon, that leaks int the surrounding shell where hydrogen is burning. The carbon then combines with nitrogen to create the carbon-nitrogen-oxygen (CNO) cycle, with convection distributing the nitrogen throughout the star. Eventually, this nitrogen-rich material is shed into space, enriching the surrounding gas.
These massive stars collapse directly massive black holes when they die GS 3073 contains an actively feeding black hole at its core, which is potentially a remnant of one of these supermassive star. If confirmed the detection can solve two mysteries at once, the origin of the nitrogen as well as the black hole. The research provides scientists with a new window into the early universe. A paper describing the research has been published in the Astrophysical Journal Letters.