Researchers searching for signs of extraterrestrial technologies have stumbled upon a pulsar at the center of the Milky Way, a discovery that could offer new opportunities to test Einstein’s theory of gravity.
Researchers from Columbia University and Breakthrough Listen, led by Karen I. Perez, were conducting one of the most sensitive radio searches for pulsars ever conducted in the central Milky Way galaxy, known as the Breakthrough Listen Galactic Center Survey, when they made the discovery.
Their key finding was an 8.19-millisecond pulsar candidate near the supermassive black hole Sagittarius A* at the center of the Milky Way, as reported in a recent study in The Astrophysical Journal.
Searching the Galactic Center
The galactic center contains the highest density of stars in the Milky Way. Looking along the line of sight toward it also offers scientists one of the richest stellar fields observable from Earth. For this reason, the galactic center was chosen as a primary target in Breakthrough Listen’s search for technosignatures.
Dr. Andrew Siemion has led Breakthrough Listen since 2023 from the Department of Physics at the University of Oxford. The initiative currently works with the Green Bank Telescope in the United States, the 64-meter Parkes radio dish in Australia, the MeerKAT array in South Africa, and other global partners. Breakthrough Listen also plans to work with the Vera C. Rubin Observatory in Chile, an advanced facility that captured its first images last summer.
A New Pulsar in the Galactic Center
Pulsars are often compared to lighthouses because these highly magnetized neutron stars emit sweeping radio beams across space. When unobstructed, the regularly emitted pulses are extremely stable. The rapid rotation of millisecond pulsars makes them among the most precise natural clocks known.
“Any external influence on a pulsar, such as the gravitational pull of a massive object, would introduce anomalies in this steady arrival of pulses, which can be measured and modeled,” said co-author Slavko Bogdanov, a research scientist at the Columbia Astrophysics Laboratory. “In addition, when the pulses travel near a very massive object, they may be deflected and experience time delays due to the warping of space-time, as predicted by Einstein’s General Theory of Relativity.”
Testing General Relativity with a Pulsar
Discovering a millisecond pulsar near the center of the Milky Way offers new opportunities for precision tests of General Relativity. Such measurements could allow scientists to probe the structure of spacetime in the extreme gravitational environment around a supermassive black hole.
Sagittarius A* has a mass roughly 4 million times that of the Sun, giving it a profound influence on its surroundings that may be detectable through pulsar timing measurements. Researchers are currently preparing follow-up observations. The team is also enlisting citizen scientists by publicly releasing Breakthrough Listen data, hoping researchers around the world will conduct additional analyses.
“We’re looking forward to what follow-up observations might reveal about this pulsar candidate,” Perez said. If confirmed, it could help us better understand both our own Galaxy and General Relativity as a whole.”
The paper, “On the Deepest Search for Galactic Center Pulsars and an Examination of an Intriguing Millisecond Pulsar Candidate,” appeared in The Astrophysical Journal on February 9, 2026.
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.