Citizen scientists help discover a Jupiter-like planet

Much of the work done in astronomy requires large groups of people cooperating and working together to make new discoveries. Although most of this work is done by professional astronomers, there are occasions when members of the public also help. Recently, citizen scientists helped analyze data from a NASA telescope to identify a gas giant planet 379 light years away.

The team of citizen scientists used data from the Transiting Exoplanet Survey Satellite, or TESS, to identify planet TOI-2180 b. It orbits a star with a mass similar to our sun, and a year there lasts 261 days, making it one of the most distant gas giants discovered outside the solar system. “The discovery and publication of TOI-2180 b was a great group effort demonstrating that professional astronomers and seasoned citizen scientists can work together successfully,” said Tom Jacobs, one of the citizen scientists who volunteered for the project, in a declaration. “It’s synergy at its best.”

Many exoplanets are spotted by looking for transits, or times when a planet passes between a star and Earth. The star’s dip in brightness can tell astronomers about the planet’s properties. However, this requires the telescope, planet, and star to be carefully aligned. It also works best with planets close to their stars.

“With this new discovery, we are also pushing the boundaries of the types of planets we can extract from TESS observations,” said researcher Diana Dragomir. “TESS was not specifically designed to find such long-orbiting exoplanets, but our team, with the help of citizen scientists, is digging for these rare gems nonetheless.”

Transits are usually spotted by computer algorithms, but in this case, because it orbits far from its star, the planet only made one transit in the data. That’s where citizen scientists came in — they helped identify potential exoplanets based on their light curves or graphs of a star’s brightness over time.

“The manual effort they put in is really big and really impressive because it’s actually hard to write code that can walk through a million light curves and reliably identify unique transit events,” said said Paul Dalba. “This is one area where humans are still beating the code.”

Now professionals and citizen scientists are eager to see what they find when TESS observes the same star again in February as they hope to find confirmation of the planet’s orbit.

“We love contributing to science,” Jacobs said. “And I love that kind of surveying, knowing that you’re in new, uncharted territory never seen by any human before.”

The research is published in The Astronomical Journal.