High School Citizen Scientists Join the Hunt for Exoplanets

There has never been a better time to be an amateur astronomer. Recent advancements in affordable “smart” telescopes have ushered in a new era of citizen science that blurs the lines between professionals and hobbyists. Career astronomers are especially keen for the assistance of sky-watchers when it comes to the confirmation and characterization of exoplanets. Recently, two citizen scientist groups (some of the members just in high school!) have contributed to academic studies confirming the existence of different planet candidates.

The first project, led by Dan Peluso (SETI Institute & LSST Discovery Alliance), used an organization of citizen scientists, known as the Unistellar Network. Organized by the Search for Extraterrestrial Intelligence (SETI) Institute and the telescope company Unistellar, this network helped confirm a warm exoplanet a bit smaller than Saturn. Members also found evidence of a second planet in the same system. The second project, led by Lauren Sgro (also at SETI), verified a warm Jupiter with the help of the Unistellar Network as well as NASA’s Exoplanet Watch, another group of amateur observers.

These efforts aren’t just fun and educational; they also serve an important scientific role — filling observing gaps that professional scientists struggle to fill. For example: NASA’s Transiting Exoplanet Survey Satellite (TESS) has thus far identified 7,203 candidate planets, many of them by only a single transit of the world across the face of its star. But only 475 of these worlds have multiple transits or other information to confirm they are real detections. This is partly because TESS observes each slice of sky for only around 27 days. Observing time is where citizen scientists can make a difference, by watching stars already suspected to host a planet.

“There are not enough professional astronomy facilities, or professional astronomers in the world to follow-up on all the TESS candidates,” Sgro says. “That’s why I believe that citizen science is absolutely needed. Without them, we could miss out on an exoplanet discovery that really allows us to finally understand planet formation in our own solar system.”

Networks of amateur astronomers can not only bypass the limited observing time, visibility, and unpredictable weather conditions at professional facilities, they can also coordinate multiple observations around the world to cover an object for hours or even days at a time. Several international groups are (or have been) involved in such endeavors: ExoClock, Kilodegree Extremely Little Telescope Follow-Up Network, Exoplanet Watch, and the Unistellar Network, to name a few.

The aforementioned studies headed up by Peluso and Sgro are both intriguing, not just for their involvement of citizen scientists but for their targets, both of which are “warm” gas giants that orbit their star closely and with equilibrium temperatures below about 1000K (1340°F). One planet is a bit smaller than Saturn (shown in the plot above); the other is in the Jupiter class.

As opposed to their cold namesakes in the solar system and hot Jupiters discovered elsewhere, these worlds seem to represent a transitional stage. Future follow-up of these worlds could inform our understanding of how hot, warm, and cold giant-planet populations in a system form, evolve, and possibly migrate.

As part of Peluso’s study, he mentored Galaxy Explorers, an astronomy program for high school students at the Chabot Space & Science Center in Oakland, California. The group is part of the Unistellar Network, and during weekly sessions at the Science Center, students are taught about space science and observing on Unistellar “eVscopes.” These smart telescopes do live processing to produce images viewable via a smartphone or tablet. The photometric data can then be uploaded through the telescope's phone app to an online catalog, which is accessible to professional astronomers for compilation and analysis.

“It’s pretty cool to see stuff that I know from astronomy books on the telescope or on my phone,” says Richard Purev (Oakland Technical High School). “But one of the best parts about observing is not just looking up at the stars, but also looking around me to my friends and peers.”

The Galaxy Explorers collected the data for Peluso’s exoplanet confirmation study during a memorable all-night observing session on February 18, 2023. Between hourly telescope maintenance on the roof, the students entertained themselves with movies, games, musical performances, and more.

Beyond inspiring a love of sky-watching, the program has also paved the way for several students to pursue degrees in astronomy. Naina Srivastava just graduated from Campolindo High School and will be attending Columbia University in the fall to study astrophysics.

“This experience made me realize that I'm really interested in astrophysics research,” she says. “So I cold-called the head of the astrophysics department at Berkeley. I've been researching with her for about two years now.”

Peluso thinks initiatives such as those using Unistellar’s smart telescopes could signal a positive change for astronomy. “Under the right circumstances,” he says, “they can help towards a more democratized science, where students and the public can learn by doing, and the ‘doing’ actually contributes to important research — an engaging and motivational win for education and science!”