Valley News – Dartmouth researcher’s work is out of this world

HANOVER — When Elisabeth Newton, who works in the Department of Physics and Astronomy at Dartmouth College, realized she had made a remarkable discovery — a new planet in a stellar system not far from our own — she was eager to confirm the news.

She texted her Columbia University colleague Jason Curtis, who was tied up in matters more mundane.

“He was at jury duty, so he was on his phone trying to do science while sitting in the waiting room,” Newton recalled. “When he got home he was like, ‘Actually, I think there are two planets.’ ”

That was about two years ago. Then, Newton says, “last year we were like, ‘Oh! There’s a third planet here.’ ”

Now, the discovery of three new planets is gaining attention following a paper Newton and her colleagues published in The Astronomical Journal in January.

“I was pretty excited. I liked telling people,” Newton, an assistant professor, said of the days after the findings. “I was like, ‘So there’s this young cluster, and now we know what its age is, and guess what? There are planets in it too!’ ”

The trio of young planets is located in a stellar system scientists call TOI-451.

Planets TOI-451b, TOI-451c and TOI-451d are all larger in size and mass than Earth and reside in the Pisces-Eridanus stream, a group of stars significantly younger than our solar system. It sits about 404 light-years away.

Newton makes it sound simple, but the story of how she and her team identified these new planets is vast. The researchers relied on crisscrossing data and research from across the globe.

The search began in February 2018, when Newton and a group of co-workers formed a collaboration they dubbed THYME, or TESS Hunt for Young and Maturing Exoplanets, at a conference held at Biosphere 2 in Arizona.

They were gearing up for the April launch of TESS, NASA’s current exoplanet mission. That’s when the team could begin paying attention to public alerts from the spacecraft.

“Each of those alerts is a candidate planet,” Newton said. “It looks like a planet but it may not in the end in fact be a planet.”

THYME would do the follow-up work in hopes of confirming the existence of, hopefully, young planets.

The association of stars home to TOI-451 wasn’t known at the beginning of the TESS mission either.

“It took data from the European Space Agency’s Gaia mission, which is measuring the positions and motions of stars for a different team to find it,” Newton said. “The Gaia researchers noticed that there was a large, associated group of stars. But they didn’t know the age.”

Newton heard about new research identifying these as young stars while visiting friends in New York and realized the potential the stellar association had in planet hunting.

She cites the 2,662 exoplanet discoveries made by NASA’s recent Kepler Mission as all the more reason to be excited about finding juvenile planets.

“The thing is that all of these planet discoveries orbit stars that are generically old — a billion, 5 billion, 10 billion years old,” she said. “So by looking at young planets, we’re trying to understand how this older population came to be. They provide us a snapshot in time of an earlier point in a planet’s history.”

Once the discoveries were made, Newton began the arduous process of gathering follow-up data.

“These papers do go faster because they’re large collaborations,” she said.

There are about 50 co-authors on the paper Newton published in January.

In addition to Newton’s research team, the byline includes a professor from Tokyo and an amateur observer in Australia.

“The telescopes we used are from all over the world too,” she said. The project utilized data from the Spitzer Space Telescope, as well as the SALT telescope in South Africa that Dartmouth has a share in, and observations made in Chile and California.

Newton stresses the collaborative reality of this kind of work.

“I managed the whole project and had a lot of responsibility for it,” she said, “but many people contributed in significant ways — doing things that I eventually could have gained the skills to do but certainly it would have taken a long time to learn how to do all of that myself.”

Using that time saved, today Newton expands her horizon-broadening work with the TESS data.

“There’s another TESS planet in a group of stars that researchers don’t know much about yet,” she said.

“I’m looking at things that no one has looked at before, And that feels pretty cool.”

She also continues work in dating the Pisces-Eridanus stream, hoping to get a better picture of the history, and therefore the future, of space.

Frances Mize can be reached at [email protected].