To date there have been no convincing direct detections of Pop III stars - the first stars, because these stars that formed in the early universe are very far away and too faint for our telescopes on the ground or in space

Shortly after the beginning of the universe with the big bang, the first stars, whose composition was mainly hydrogen and helium, began to form. The properties of these first-generation Pop III stars are very different from stars like our Sun or even stars forming today. They were very hot, huge in size and mass, but their lives were very short.
Pop III stars are the first factories to synthesize most of the heavy elements from hydrogen and helium around us today. They are also very important in the creation of later generations of stars and galaxies. But to date there have been no convincing direct detections of Pop III stars, because these stars formed in the early universe are too far away and too faint for our ground-based or space-based telescopes.
For the first time, scientists from the University of Hong Kong have discovered an innovative method for discovering these first stars in the early universe. A new study led by Prof. Jane Lishin Dai suggests that the Pop III star could be torn apart by tidal forces if it entered the environment of a supermassive black hole.
.
In such a Tidal Disruption Event (TDE), the black hole devours the star debris and produces very luminous flames. The researchers studied the complex physical process involved and showed that these flames can shine across billions of light years to reach us today. Most importantly, they found that the unique signatures of these TDE flares could be used to detect the existence of Pop III stars and gain insights into their properties.
"The energetic photons travel a very long distance, so the flame's timeline will be stretched because expansion of the universe. These TDE flares will wax and wane over a very long period of time, which sets them apart from the TDEs of solar-type stars in the nearby universe," said Professor Jane Dye, principal investigator and corresponding author of the project.
"It is interesting that not only is the timeline of the flames stretched, so is their wavelength. The visible and UV light emitted by the TDE will be transferred to AA emissions when it reaches Earth," adds Dr. Rudrani Kar, the first author of the article.
The discovery is especially exciting because two of NASA's flagship missions, the launched James Webb Space Telescope and the soon-to-be-launched Nancy Grace Roman, can observe such AA emissions from great distances.
Prof. Priya Natarajan, co-author of the paper, noted: "Thanks to Roman's unique abilities to simultaneously observe a large area of the sky and peer deep into the early universe, it is a promising means of detecting the TDE flares of these Pop III stars, which will serve as a discovery bypassing the stars themselves".
PhD student Janet Chang, a co-author of the paper, added: "We expect Roman to discover several dozen such events every year if we adopt the right observational strategy."
In light of these findings, the next ten years have great potential to identify these unique sources, leading to exciting discoveries about Pop III stars and solving the mysteries of the universe's formation.