Scientists have detected faint radio pulsations from a neutron star that had been considered "radio-silent" for decades. The discovery could significantly change our understanding of the number of pulsars in the Milky Way.

What astronomers found

An international team led by Zhang Lei from the National Astronomical Observatories of the Chinese Academy of Sciences, using the MeerKAT radio telescope in South Africa, recorded faint radio pulsations from the central compact object 1E 1207.4-5209. The object, located in a supernova remnant at a distance of 10,000 light-years from Earth, has now been given the poetic name "Blue Eye Pulsar."

The pulsar "flashes" radio waves every 424 milliseconds, which exactly matches its known rotation period. When the radio data was combined with X-ray images, the object indeed began to resemble a blue eye.

Why this matters

Until now, about a dozen neutron stars in supernova remnants were considered "dead" in the radio range and classified as central compact objects (CCOs). It was assumed that their magnetic fields were too weak to generate detectable radio beams.

The new discovery shows that some of these objects do emit, but very faintly. This could mean that there are significantly more pulsars in the Galaxy than previously thought.

History of the "Blue Eye"

The supernova that left behind this pulsar exploded more than 4,100 years ago. In 2015, astronomers recorded a "glitch" in it — a sudden slight spin-up. According to the study's authors, it was this glitch that may have changed or strengthened the star's magnetic field, "turning on" the faint radio pulsations.

Scientists plan to continue observations. If the pulsations weaken or disappear over time, it would confirm their hypothesis.

Implications for astronomy

The discovery could explain why pulsars have not yet been detected in some supernova remnants (for example, in the famous SN 1987A). It is possible that they are simply "whispering" too quietly.

The work was published on June 25 in the journal Nature Astronomy.

In brief

Astronomers have for the first time recorded faint radio pulsations from the neutron star 1E 1207.4-5209, previously thought to be "radio-silent." The object, named the "Blue Eye," is located in a supernova remnant at a distance of 10,000 light-years. The discovery could mean that there are significantly more pulsars in the Galaxy than previously assumed, and many of them simply emit too faintly. This is an important step in understanding the evolution of neutron stars after supernova explosions.