A red giant star that happens to be 16,000 light-years away seems to be a legitimate member of the second generation of stars in the Universe. Considering the chemical composition, it seems to contain elements produced in the life and death of a single first-generation star. Consequently, with its aid, we might even find the first generation of stars ever born, from which none have been discovered yet. Moreover, the researchers performed their analysis using photometry, a procedure that measures the strength of light, thus providing a new way to find such ancient objects.
The researchers wrote in their paper that the discovery of SPLUS J210428.01−004934.2 i.e., a highly metal-poor star selected from its narrow-band S-PLUS photometry has been confirmed by medium and high-resolution spectroscopy. These observations are part of a continuing effort to confirm low-metallicity candidates identified from narrow-band photometry using spectroscopy.
Although we think that we have a pretty good idea of how the Universe grew from the Big Bang to the stars rich beauty we know and love today, the first stars to born in the ancient darkness, known as Population III stars, remain something of a mystery.
Nowadays, the formation process of stars gives us some clues about how these early stars came into existence, but until we find them, we’re restricting our knowledge on incomplete information.
Population II stars are the next few generations following Population III stars. Of those, the generation immediately succeeding Population III are possibly the most interesting, since they are the closest in composition to Population III.
Today’s stars i.e., Population I have the highest metallicity. And stars which were born when the Universe was very young have very low metallicity, and the earliest stars are known as ultra-metal-poor stars or UMP stars. These UMPs are considered legitimate Population II stars which are enhanced by material from only a single Population III supernova.
Using a photometric survey called S-PLUS, a team of astronomers led by the National Science Foundation’s NOIRLab identified SPLUS J210428-004934, as having average metallicity for a UMP (ultra-metal-poor) star.
Additional UMP stars identified from S-PLUS photometry will considerably improve our knowledge of Population III stars and enable the likelihood of finding a metal-free low-mass star still living in our Galaxy to date, the researchers wrote.