Astronomers mining an increasingly rich trove of TESS exoplanet data

An artist’s impression of a Jupiter-like planet orbiting very close to an evolved, dying star. Three such planets were recently confirmed in data originally collected by NASA’s Transiting Exoplanet Survey Satellite. Image: Karen Teramura/University of Hawaiʻi Institute for Astronomy

NASA’s Transiting Exoplanet Survey Satellite has now identified more than 5,000 possible exoplanet candidates – TESS Objects of Interest, or TOIs – mostly from a faint star search led by Michelle Kunimo, a postdoc at MIT. While TOIs are, by definition, unconfirmed, astronomers are confident additional observations will add to TESS’s list of known exoplanets.

“This time last year, TESS had found just over 2,400 TOIs. Today, TESS has reached more than twice that number — a huge testament to the mission and all the teams scouring the data for new planets. I’m excited to see thousands more in the years to come!”

Launched in 2018, TESS is now observing the northern sky and ecliptic plane, including regions previously examined by the Kepler spacecraft during its original and extended K2 missions. The latest batch of TOIs were added in late December.

“With data from the first year of the extended mission, we have found dozens of additional candidates to TOIs found during the prime mission,” said TOI manager Katharine Hess. “I am excited to see how many multi-planet systems we can find during the rest of the extended mission and in upcoming years with TESS.”

It will take additional observations by astronomers around the world to confirm whether a TOI is, in fact, an actual exoplanet. Three such confirmations were announced at the American Astronomical Society’s winter meeting earlier this month.

A team led by Samuel Grunblatt, a postdoctoral fellow at the American Museum of Natural History and the Flatiron Institute in New York City, found three gas giants in TOI data. The planets have some of the shortest-period orbits around subgiant or giant stars yet found and one of them, TOI-2337b, likely will be consumed by its host star in less than a million years.

“These discoveries are crucial to understanding a new frontier in exoplanet studies: how planetary systems evolve over time,” Grunblatt said, adding “these observations offer new windows into planets nearing the end of their lives, before their host stars swallow them up.”

Said co-author Nick Saunders, a graduate student at the University of Hawai’i Institute for Astronomy: “We expect to find tens to hundreds of these evolved transiting planet systems with TESS, providing new details on how planets interact with each other, inflate and migrate around stars, including those like our Sun.”