Astronomers Detect a Mysterious Seven-Hour Space Signal — And They May Finally Know What It Was

For decades, astronomers have grown used to the universe sending strange signals our way. Some are bursts of energy that last only milliseconds. Others flicker like cosmic lighthouses, spinning steadily as they cross our line of sight. But in early observations that resurfaced recently, scientists noticed something very unusual—a radio signal pulsing once every seven hours.
This was not normal.
Most cosmic radio sources pulse rapidly, sometimes dozens or even hundreds of times per second. A signal that fired off only once every seven hours felt almost impossible. Even stranger: the mysterious object powering it seemed too energetic to be completely dead, yet too slow to fit into any known category.
For years, astronomers had more questions than answers. What could possibly create such a slow, steady beat across the cosmos? Was it a star? Something collapsing? Something interacting? Or was it an entirely new type of object?
Now, scientists believe they finally have an explanation—one that expands our understanding of how extreme the universe can be, even in the quietest corners of space.
A Cosmic Mystery Begins
The signal was first detected by radio telescopes scanning the sky for transient events—short-lived flashes or pulses that appear unexpectedly. These surveys are often used to search for fast radio bursts (FRBs), some of the universe’s most powerful and short-lived explosions of energy.
But this new signal didn’t behave like an FRB at all.
Instead of being a one-time burst lasting milliseconds, the object flashed repeatedly, always at the same interval: every seven hours. It was like a heartbeat—slow, steady, and strangely precise.
Astronomers originally believed no known object could produce such a pulse rate. Usual suspects like pulsars and magnetars spin far too fast. Their strong magnetic fields cause them to rotate rapidly, producing radio emissions in tight intervals. A pulse every few seconds is normal. Even a minute between pulses is rare.
But seven hours?
That was unheard of.
The Object That Shouldn’t Exist
The odd signal likely came from a compact object—either a white dwarf or neutron star—both of which form after a star runs out of fuel and collapses. These stellar remnants are extremely dense, often holding a Sun’s worth of mass in an object the size of a city or a planet.
Normally, neutron stars spin incredibly fast because they conserve angular momentum when collapsing. Think of an ice skater spinning faster as they pull their arms inward.
This is why pulsars pulse quickly.
To get a neutron star to rotate once every seven hours, it would need to be extraordinary—either extremely old, extremely weak, or affected by an outside force.
The long pulse period was such a problem that some researchers wondered if the signal was even coming from a compact star at all.
But after years of analysis, astronomers now believe the culprit might be something far stranger: a highly magnetic, slowly rotating white dwarf, or possibly a magnetically powered neutron star in a unique evolutionary stage.
Both possibilities open new doors in astrophysics.
A Magnetic Monster With a Slow Spin
The leading hypothesis today is that scientists may have discovered a magnetically active white dwarf acting like a pulsar. This would make it part of a very rare and unusual class of objects—ones that blur the line between pulsars and stars once thought to be inert.
White dwarfs are usually quiet, slowly cooling remains of stars like our Sun. They don’t typically pulse in radio frequencies, and they don’t usually have intense magnetic fields strong enough to act like a beaming lighthouse.
But if a white dwarf somehow retained or amplified a powerful magnetic field, it could theoretically emit stable pulses just like a neutron-star pulsar—only at a far slower rate.
This idea, once considered nearly impossible, gained support when astronomers discovered other unusual white dwarfs with bizarre magnetic activity. The seven-hour signal might be the clearest example yet.
If true, this would be the first strong evidence of a white dwarf pulsar—a type of object astronomers long suspected could exist but had almost no observational proof of.
Or… a Neutron Star in Disguise?
The second explanation is that the source could be a neutron star after all—but one in a rare evolutionary phase where its magnetic field is interacting with surrounding material in a way that slows its rotation dramatically.
Some neutron stars can slow down over millions of years, especially magnetars with extremely strong magnetic fields. If one were old enough and isolated enough, its pulse rate might stretch into hours.
This would make it a transition object, one that helps scientists understand the lifespan and aging process of neutron stars.
Why a Slow Signal Matters
To the average person, a star pulsing every seven hours might not sound like much. But to astronomers, it's important because it:
Expands the known limits of stellar behavior
Challenges existing models of how compact objects evolve
Suggests new categories of slow, magnetically active stars
Proves the universe still holds surprises in even its quietest corners
The discovery also demonstrates how much we still don’t know. Even dead stars—objects that should have burned out long ago—can surprise us with new behaviors.
The Universe Still Whispers Secrets
The seven-hour pulse underscores something scientists love most about space: every time we think we’ve seen everything, the universe delivers something new, mysterious, and awe-inspiring.
What began as an odd signal transformed into evidence for a whole new type of stellar activity. Whether the culprit is a slow, magnetic white dwarf or an aging neutron star, astronomers have gained valuable insight into cosmic evolution.
And somewhere in the depths of space, the signal continues—steady, rhythmic, and patient—reminding us that the universe still has stories to tell, one pulse at a time.