Constable: A star is born, as Wheaton native makes astrophysics history

In his adolescent dreams as a student at Wheaton Warrenville South High School, Brian Welch fantasized about a pie-in-the-sky career as a star tight end with the Chicago Bears.

Instead, the 27-year-old astrophysicist discovered the oldest and most distant star known to man. And he got to name it.

"It was pretty much an accidental discovery," says Welch, lead author of the paper describing the discovery for the March 30 edition of Nature, which has made him a darling of the astrophysics world, earning him interviews with The New York Times, Washington Post, the British Broadcasting Corp. and other news outlets far beyond the narrow niche he expected.

"It wasn't a single 'eureka moment.' It was more of a slow burn," Welch says of his discovery. "It was a really long and slow process."

Working on his doctoral degree at Johns Hopkins University, Welch was given an assignment in 2019 from Dan Coe with the Space Telescope Science Institute, also in Baltimore. Welch says he needed "to figure out what was going on" with the Sunrise Arc galaxy by studying images from the Hubble Space Telescope. Galaxies that are far away generally look like clusters of light from millions of stars "blended together," Welch says.

But a cluster of galaxies also can create a gravitational field that distorts and magnifies the light from galaxies behind that cluster, which allowed Welch to see the distant star as if he were looking through a giant magnifying glass. Images of "clumpy structures" were magnified by "gravitational lenses," which "bend the fabric of space," and make massive objects "larger and brighter in our telescopes than we'd see otherwise," Welch says.

In the midst of the clusters of lights from millions of stars, one star was magnified.

Because of pandemic restrictions, Welch was working from his basement office in the Baltimore row house he shares with his wife, April.

"We might be on to something really big here," Welch remembers thinking. "It's about 50 times the mass of the sun and about a million times brighter. We're looking back 13 billion years into the past."

The star is long gone, but its light took 12.9 billion years to reach Earth. Because the universe is constantly expanding, wavelengths get stretched as light travels, and longer wavelengths of light appear redder, allowing scientists to determine distance. NASA hailed the record-breaking discovery an "extraordinary new benchmark." Seeing that star as it was then gave Welch the view established about 900 million years after the Big Bang and the birth of the universe. The previous record for oldest star, detected by Hubble in 2018, was Icarus, which dates back about 9 billion years.

"Since I'm technically the one who discovered it, I got to pick out the name," says Welch. "My mom suggested I just name it Brian's Mom's Star."

But according to rules set by the International Astronomical Union, stars shouldn't be named after people or fictional characters. The names should be short, not confusing and adhere to lots of other rules.

Because the star he discovered occurred in the "cosmic dawn," when the universe was relatively new "and the lights were just turning on," Welch chose the name, Earendel, an Old English name that means morning star.

"I think it's because I'm a Tolkien fan," Welch says. J.R.R. Tolkien, author of "The Hobbit" and "Lord of the Rings," knew the word Earendel and named a character Earendil. Welch was looking through names for morning star, and thought Earendel fit.

"It seems like a long time, but 900 million years is still very close to the beginning," Welch says.

Growing up in Wheaton as the son of Dave and Pat Welch, and sister of Christina, who is now a lawyer, Welch played football in high school and for three years at the University of Chicago. At 6-foot-6, he might be the tallest astrophysicist, as those worlds rarely intersect.

"My two high school physics teachers are the ones I really need to thank for getting me into this," Welch says. His first physics teacher, Tom Todd, who died in 2014 from lymphoma, "was a really awesome teacher who made everything interesting," and his AP physics teacher, Jim Stankevitz, who retired in 2018, "made it really fun," Welch says.

As a tight end on the football team, "I mostly ended up blocking for other people to get their names in the lights," Welch says.

He is finishing the paper he'll defend to earn his doctorate.

"I have yet to come up with a snappy title, but it's generally about distant galaxies and galaxy clusters," says Welch, who already has a job lined up with the NASA Goddard Space Flight Center in Greenbelt, Maryland.

"I'm definitely not expecting to get anything this big again," Welch says in noting his star discovery. "But I'm going to keep my eyes open, and if lightning strikes twice, that would be amazing."