One evening last fall, University of Cincinnati astrophysics graduate Paul Smith waited anxiously for data to start rolling across his computer screen from the James Webb Space Telescope a million miles from Earth.
The telescope was directed at an object even farther away — much farther away. Smith is studying a planet 901 light years away. That means light from its star takes 901 years to reach Earth.
The planet is named after this star, TOI-2031A, in accordance with NASA's unpoetic, numbered naming conventions. The TOI stands for Transiting Exoplanet Survey Satellite Object of Interest.
Even though it was a clear night, the star was too faint to see with the naked eye. Its starlight captured in the space telescope was generated in the Middle Ages.
Smith and his research partners beat out other scientists for precious telescope time. Roughly 90% of research applications don't make the cut each year in the competitive peer-review process.
Now they were hoping their calculations were correct and the planet would cross in front of its star during their allotted observation time.
Using the telescope's powerful near-infrared spectrographic sensors, researchers would be able to learn more about the planet and its atmosphere as it transited its star's face. As leader of the data analysis for the project's first planet, Smith got to retrieve the data, what astrophysicists call the first look.
"It was a lifelong dream of mine coming true. I was up all night to get the first look at the data," he said.
Smith and his research colleagues presented their findings on TOI-2031Ab at the American Astronomical Society meeting in Denver in April.
Physicists call planets outside our solar system exoplanets. To date, astrophysicists have identified about 6,400 of them.
Smith and his international collaborators from 19 other institutions are studying gas giants like Jupiter to learn more about their atmospheres and why so many of them orbit so close to their stars. The exopolanet is a quarter bigger in circumference than Jupiter, the biggest planet in our solar system, although it has 20% less mass.
Smith regularly travels to Ohio State University to meet with some of his project co-authors, grad student Everett McArthur and Professor Ji Wang. And he talks regularly with Peter Gao from the Carnegie Science Institute.
"We're trying to figure out how these big gas giants got there. We're studying the formation and migration pathways of big planets," Smith said. "Where do they form in their solar systems and how do they get so close to their stars?"
TOI-2031Ab was discovered just last year, the only known planet in its solar system. The exoplanet orbits its star closer than Mercury orbits the sun.
Its year lasts just six Earth days as it hurtles through space four times faster around its star.
Researchers can study its atmosphere using the portion of its star's light that slices through its atmosphere on its way to the James Webb Space Telescope.
"The atmosphere is very similar to Jupiter's — mostly hydrogen and helium, water and carbon dioxide," Smith said.
Cincinnati Observatory astronomer Wes Ryle, who was not part of the study, said planets outside our solar system are helping us understand our own.
"Exoplanets are one of the hottest topics in astrophysics right now, with the ultimate goal of learning how our solar system compares to others and the likelihood of finding other habitable worlds," Ryle said. "Studies like this help evaluate the role of gas giant planets and their migration in creating a planetary system."
