Astronomers have detected extreme, never-before-seen behavior from a rare kind of pulsar and stumbled on a surprising link to one of astronomy’s biggest current mysteries. Using 174 hours of radio observations, researchers detected PSR J1227-4853, a rapidly spinning neutron star known as a “transitional millisecond pulsar,” which unleashes hundreds of ultrashort, ultrapowerful “giant pulses.” Their paper was published in The Astrophysical Journal on July 31.
Rare spinning stars
Neutron stars that rapidly rotate, completing one rotation in less than about 30 milliseconds, are called millisecond pulsars (MSPs). Among them is a rare class of neutron stars called transitional millisecond pulsars that swing between two different observational states: an accretion-powered state in a low-mass X-ray binary system and a radio-powered millisecond pulsar state. So far, only three transitional MSPs have been confirmed to exhibit this switching behavior.
In this study, Saptarshi Sarkar of the National Center for Radio Astrophysics in India and colleagues studied the third of these confirmed systems, PSR J1227−4853. Discovered in 2014 using the Giant Metrewave Radio Telescope (GMRT), it completes one rotation every 1.69 milliseconds.
What made it an exciting target was its unusually strong magnetic field at the pulsar’s “light cylinder”—an imaginary cylinder centered on the pulsar with a radius at which material co-rotating with the star’s spin would have to move at the speed of light. It also showed a high spin-down luminosity, which is the rate of its kinetic-energy loss as its rotation slows down.
These properties are linked to a rare phenomenon called giant pulses (GPs)—extremely brief, extraordinarily bright radio flashes reaching up to 10,000 times brighter than the pulsar’s normal signal. To date, only 19 pulsars have been found that produced them. None of the transitional millisecond pulsars have shown this behavior, so the team was motivated to check whether this rare pulsar also produces such giant pulses.
Pulses from hot spots
The team combined two datasets from the upgraded GMRT: a larger set spanning about 165 hours over five years and a smaller, higher-resolution follow-up set spanning nine hours of observations taken over less than six months. After carefully filtering out radio interference, they confirmed 235 genuine giant pulses, some lasting barely over a millionth of a second.
The pulses were found to be produced from two “hot spots” in the pulsar’s spin cycle. Notably, none were found in a separate region where some other giant-pulse-emitting pulsars do show activity. This shows that the emission is not random and comes from a highly localized region of the pulsar’s magnetic environment. On Dec. 6, 2020, the pulse rate spiked dramatically, with 114 giant pulses detected in a single hour.
The team found that, of the two hot spots, pulses from one region were extremely narrow—as short as 1.28 millionths of a second—and brighter than those from the second region. This distinction may suggest that the two regions represent different emission mechanisms.
The rarest of rare
This is the first time this kind of extreme pulse behavior has been observed in a transitional millisecond pulsar. However, this raises the question of whether this kind of extreme radio activity is a common trait of transitional pulsars in general or something unique to this system.
The elevated activity of more than 100 pulses per hour, astronomers say, follows a statistical pattern that closely resembles the bursting behavior seen in repeating fast radio bursts (FRBs). The team writes that this may suggest “potential phenomenological parallels between GPs from compact binaries and repeating FRBs.” Because violent bursting behavior in repeating FRBs is poorly understood, the similarities found in pulsar giant pulses may help decode their behavior.
Researchers note that the framework the team used to describe the processes in this system does not account for certain complex behaviors. Alternative models that incorporate changes in activity over time and complex pulse-clustering patterns may give a more realistic view of burst activity. Nevertheless, researchers say that this study could offer an “interesting direction for a future study.”
Written for you by our author Shreejaya Karantha, edited by Lisa Lock, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive.
If this reporting matters to you, please consider a donation (especially monthly). You’ll get an ad-free account as a thank-you.
Publication details
Saptarshi Sarkar et al, Detection of Giant Pulses from the Transitional Millisecond Pulsar J1227-4853, The Astrophysical Journal (2026). DOI: 10.3847/1538-4357/ae8798
© 2026 Science X Network
Citation:
Rare pulsar unleashes 114 giant pulses in a single hour (2026, September 7)
retrieved 7 September 2026
from https://phys.org/news/2026-08-rare-pulsar-unleashes-giant-pulses.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.