Citizen scientists working with the Kilonova Project to identify astrophysical transients in observations by the Gravitational-wave Optical Transient Observer (GOTO) have achieved their first confirmed success, as revealed in a new paper published in Astronomy & Astrophysics, which reports the discovery of an exploding star.
The project relies on close to 3,700 volunteers who have so far aided in classifying nearly 240,000 objects from GOTO observations. Citizen scientists significantly increased response time, enabling timely follow-up collections from observatories.
Gravitational-wave Optical Transient Observer
“I literally screamed with joy when I saw that I was going to be a co-author of the research paper,” said Kilonova Seekers volunteer Svetoslav Alexandrov. “I’m certain that people on the street raised their eyebrows when they saw me screaming and dancing, but I didn’t care. I knew I am a co-discoverer of something significant, and this was all that mattered.”
Active since 2017, GOTO consists of two robotic optical telescope arrays, located in Spain and Australia, designed to search the skies for gravitational wave events. While astronomers can aim the systems, each telescope within GOTO has a fixed orientation due to its static mounting. GOTO operates by collecting multiple observations over time for comparative analysis to detect transient events.
The Kilonova Seekers project helps make sense of the vast amounts of data gathered by GOTO. With volunteers participating online from around the world, the project has been running for almost two years. The sheer data volume presents challenges even for machine learning algorithms, but human participants excel at interpreting uncertainty.
Volunteers are tasked with examining two images—one showing a recent view of a patch of the night sky, the other showing the same area as observed previously—and identifying any differences that might indicate something unusual.
Citizen Scientists View an Exploding Star
The exploding star identified in the new paper marks the Kilonova Project’s first confirmed discovery. The object increased in brightness by a factor of 2,500 compared to observations made just two days earlier. After analysis and classification by astronomers, the star was designated GOTO0650, a cataclysmic variable star.
“Kilonova Seekers is a unique opportunity for members of the public to take part in true real-time astrophysics,” said Dr. Tom Killestein, Kilonova Seekers co-lead. “Remarkably, public volunteers identified this star as an object of interest within 3 1/2 hours of the image being taken by the GOTO telescopes – this discovery could have been missed among many other objects without their efforts.”
Following the identification, volunteers remained involved as Swift and Einstein Probe space observatories captured follow-up data. The star’s remarkable brilliance was also bright enough for amateur astronomers to contribute their own observations from home, enriching the dataset for professional analysis.
That rapid response—facilitated by public involvement—meant that images were reviewed quickly rather than languishing in queues. As a result, researchers obtained an unusually complete dataset for the event, including spectroscopic, X-ray, and UV measurements.
Cataclysmic Variable Stars
A cataclysmic variable star intermittently experiences dramatic fluctuations in brightness, driven by the transfer and consumption of matter between binary companions. The explosive flash occurs when the material being consumed reaches critical density and temperature, producing the visible outburst. GOTO0650 appears to be a period bouncer, a rare final evolutionary state of cataclysmic variable stars.
“Citizen science is a powerful way to make novel serendipitous discoveries in vast datasets that would normally need to be analysed in depth by scientists,” said Dr. Lisa Kelsey, Kilonova Seekers co-lead.
“With over 2.8 million classifications so far, the discovery of GOTO0650 is really the pinnacle of 2 years of consistent hard work from our volunteers,” Kelsey added. “Without the Kilonova Seekers volunteers flagging this object, rapid follow-up would not have been possible, and this object may have been missed entirely.”
The new paper, “GOTO065054+593624: An 8.5 mag Amplitude Dwarf Nova Identified in Real time Via Kilonova Seekers,” appeared on July 1, 2025, in the Astronomy & Astrophysics
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.