1st generation of stars may soon be identified: Black hole hunter

With NASA-led James Webb Space Telescope continuing to reveal secrets, announcements could soon be made about a possible detection of the first generation of stars ever formed in the universe.

“There are some signatures that are predicted and there have been detections now of several objects we believe have those characteristics. So, that’s super exciting. We had never imagined we would start seeing right back to this very first generation of stars, even with James Webb,” Priyamvada Natarajan, leading theoretical astrophysicist and Chair of Astronomy at Yale, told The Tribune in an interview on Thursday.

In New Delhi to speak at the Indian International Centre where she presented groundbreaking findings that suggest there ought to be more than one way to make black holes, Natarajan said James Webb telescope recently showed that her findings might well be true.

“Traditionally we believe there’s one way to make black holes — that black holes are the end states of stars. So stars live out their lives and leave behind these black holes, but we found one object in 2023 that really confirms to all predictions that I have made...suggesting that there’s more than one way to make black holes,” said Coimbatore-born Natarajan, included in the TIME 100 list of most influential people in the world in 2024 for her contributions to Astrophysics.

On the first stars ever formed, Natarajan, famous as the black hole hunter, said science has started to detect the first tiny galaxies ever formed and the first ever stars ever formed, which is “super exciting”. Asked if we now know when these galaxies and stars were formed — something not known so far — Natarajan said. “It’s starting to be known now. The age of our universe is 13.8 billion years and we believe that maybe 300 to 400 million years after the Big Bang, the first stars formed. We previously thought they formed within the first billion years but now we’ve been able to narrow it down,” she said, adding that scientists now also know the actual sequence of events in the universe.

“The order of when the first stars, first galaxies, first black holes formed, how they evolved and the larger properties of the universe within which these cosmic objects kind of inhabit...these are now known,” she said referring to findings from the James Webb Telescope, the NASA-led international project with contributions from the European Space Agency (ESA) and the Canadian Space Agency (CSA), launched in 2021.

It’s an orbiting infrared observatory and unlike the Hubble Telescope, it is unmanned.

Asked if there could be habitable planets other than the Earth, Natarajan said, “Absolutely. We now know about the existence of about 8,000 other planets around other stars. What we don’t know is if any of them are actually habitable to the kind of life forms we are familiar with, like carbon-based life.”

The Joseph and Sophia Fruton Professor of Astronomy and Professor of Physics at Yale, Natarajan added that the world has so far surveyed only a very small portion of its own galaxy and has found abundant exoplanets. “So there is absolutely no reason to believe that there isn’t some kind of life out there somewhere. Because there are more planets than stars… so you have so many possibilities.”

She did not put timelines to when such habitable planets could actually be found. Flagging serendipity in science, she said, “It could be next year or it may take decades.”