Researchers from Columbia University have identified a potential millisecond pulsar spinning every 8.19 milliseconds close to Sagittarius A*, the supermassive black hole at the Milky Way's center. This discovery, part of the Breakthrough Listen Galactic Center Survey, could provide insights into space-time under extreme gravity if confirmed. The findings were published in The Astrophysical Journal.
Scientists scanning the Milky Way's core have detected a promising signal from what may be an ultra-fast pulsar near Sagittarius A*. The object, a candidate millisecond pulsar (MSP) with a spin period of 8.19 milliseconds, was found during the Breakthrough Listen Galactic Center Survey, one of the most sensitive radio searches for pulsars in the galaxy's turbulent central region.
The survey was led by Karen I. Perez, a recent PhD graduate from Columbia University, in collaboration with the Breakthrough Listen initiative, which focuses on extraterrestrial signals. Pulsars, which are rapidly spinning neutron stars—dense remnants of massive stars—emit beams of radio waves that act as precise cosmic clocks. Millisecond pulsars, in particular, offer exceptional timing stability due to their fast rotation and strong magnetic fields.
If verified, this pulsar's proximity to Sagittarius A*—a black hole with about 4 million solar masses—could enable tests of Einstein's General Theory of Relativity. As co-author Slavko Bogdanov explained, "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. 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."
Follow-up observations are currently underway to confirm the candidate's authenticity. To foster collaboration, Breakthrough Listen has released the data publicly for independent analysis. Perez noted, "We're looking forward to what follow-up observations might reveal about this pulsar candidate. If confirmed, it could help us better understand both our own Galaxy, and General Relativity as a whole."
The research appears in The Astrophysical Journal (2026; 998(1):147, DOI: 10.3847/1538-4357/ae336c).