South Africa telescope catches faint pulse from Blue Eye Pulsar after decades of silence

For decades, astronomers thought the Blue Eye Pulsar, a rare neutron star in the middle of a supernova remnant, was radio-silent, but a team of scientists may have just proved that theory wrong.

A faint pulse now detected by South Africa's MeerKAT telescope suggests that some of the Milky Way's "missing" pulsars may have been present all along, just much quieter than expected, according to Space.com.

What happened?

The signal came from 1E 1207.4-5209, which is classified as a central compact object, or CCO. This small group of neutron stars has long perplexed researchers because its members do not seem to behave like typical pulsars.

Working with the MeerKAT radio telescope in South Africa, the team led by Zhang Lei at the National Astronomical Observatories of the Chinese Academy of Sciences found pulses repeating every 424 milliseconds, as Space.com reported. That timing matches the star's known spin period, reinforcing the idea that this once-silent object is actually an extremely faint pulsar.

Combined radio and X-ray images made the object look like a glowing blue eye, leading Li Di, an astronomy professor at Tsinghua University in China, to nickname it the "Blue Eye Pulsar." The neutron star is about 10,000 light-years away in the Milky Way and sits at the center of a supernova remnant created more than 4,100 years ago.

The discovery was reported on June 25 in Nature Astronomy.

Why does it matter?

The finding may help resolve a longstanding question in astronomy: why some supernova remnants seem to be missing pulsars even when scientists are fairly sure a neutron star is there.

Before this detection, about a dozen known CCOs had not been observed at radio wavelengths. That absence had led some researchers to think their magnetic fields were too weak to produce the radio beams that make pulsars visible from Earth, but 1E 1207.4-5209 suggests some of these objects may instead be far dimmer than expected.

Detecting faint signals can help scientists better understand how matter behaves under some of the most extreme conditions in the universe, including ultra-dense stellar interiors and powerful magnetic fields.

The findings also show how advanced ground-based observatories can uncover the hidden knowledge of space without requiring entirely new missions.

Researchers noted that the discovery may also change how astronomers classify older pulsars. Some stars believed to be ancient, fading emitters could instead be relatively young objects producing unusually soft radio signals.

What's being done?

Researchers believe a 2015 "spin glitch" may explain why this neutron star became detectable. A glitch is a small jump in a neutron star's rotation rate, likely caused by internal shifting within its incredibly dense interior.

Lei's team suggested the event may have boosted or altered the star's magnetic field enough to let MeerKAT detect a signal that was already extremely weak.

If the star's rotation slowly settles back to normal and the radio pulses fade again, that would support the idea that some CCOs become visible only under certain conditions.

Sensitive instruments such as MeerKAT can reveal signals that were present the whole time, expanding what scientists know about the galaxy and the tools used to study it.

The newly detected pulses from the "Blue Eye Pulsar" and the suspected role of a "spin glitch" suggest that stellar remnants once considered quiet may belong to an overlooked population of very faint pulsars.

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