If aliens contacted Earth, what would it sound like?
Such a scenario has been imagined countless times in science fiction but in reality we have no proof of the existence of extraterrestrials.
That hasn’t dampened the excitement that an advanced civilization might be out there, but the discovery of a mysterious interstellar object that emits a five-minute pulse every 22 minutes will only serve to intensify it.
What’s more, the scientists who identified it aren’t 100 percent sure what it is.
An international team of astronomers led by Australia’s Curtin University thinks it could be an ultra-long-period magnetar – a rare type of star with the strongest known magnetic field in the universe.
Weird: Scientists have discovered a mysterious stellar object that emits a five-minute pulse every 22 minutes. They think it could be an ultra-long-period magnet (illustrated in an artist’s impression).
What is a magnet?
A magnetar is a type of neutron star, an incredibly dense object composed mainly of tightly packed neutrons, formed from the collapsing core of a massive star during a supernova.
What distinguishes magnetars from other neutron stars is that they also have the strongest known magnetic fields in the universe.
For context, our planet’s magnetic field strength is about one gauss, while a refrigerator magnet measures about 100 gauss.
Magnets, on the other hand, have a magnetic field of about a million billion gauss. If a magnet were located one-sixth of the way to the moon (about 40,000 miles), it would erase data from all credit cards on Earth.
This allows them to produce extremely powerful bursts of energy over a period of seconds to minutes.
However, what is so unusual about the new discovery is that it emits radio waves every 22 minutes.
This makes it the longest-period magnetar ever detected.
It has been doing this for at least 33 years, leading to speculation that it may have some sort of link to extraterrestrials.
Lead author Dr Natasha Hurley-Walker said: ‘Whatever mechanism is behind this is remarkable.
A magnetar is a type of neutron star – an incredibly dense object made up mainly of tightly packed neutrons, created from the collapsing core of a massive star during a supernova.
Dr Hurley-Walker said the magnet in question, named GPM J1839−10, was 15,000 light-years from Earth in the constellation Scutum.
‘This extraordinary object challenges our understanding of neutron stars and magnetars, which are some of the most exotic and extreme objects in the universe,’ he added.
The stellar object is only the second detected so far.
Its discovery was due to the first sighting of an ultra-long-period magnetosphere, which produced huge bursts of energy three times an hour and was unlike anything astronomers had seen before.
Curtin University graduate research student Tyrone O’Doherty discovered – and published last year – that it ‘stumped’ scientists at the institution.
Dr Hurley-Walker said: ‘We started looking for similar objects to find out if this was an isolated incident or just the tip of the iceberg.’
Between July and September 2022, the team scanned the sky using the Murchison Widefield Array (MWA), a radio telescope in Western Australia’s Outback Waziri Yamaji Country.
It didn’t take them long to see GPM J1839−10.
Unusual: A magneto is a rare type of star that has an extremely strong magnetic field that can produce powerful bursts of energy
Space travel: Astronomers discovered the object using the Murchison Widefield Array (shown), a radio telescope in Western Australia’s Outback Waziri Yamaji Country.
Other telescopes helped confirm the discovery, including three CSIRO radio telescopes in Australia, the MeerKAT radio telescope in South Africa, the Grantecan (GTC) 10m telescope, and the XMM-Newton Space Telescope.
The team also examined the archives of the world’s premier radio telescopes and found that signals from GPM J1839−10 had been detected since 1988.
‘It was quite an incredible moment for me,’ said Dr Hurley-Walker.
‘I was five years old when our telescopes first recorded pulses from this object, but no one noticed it and it remained hidden in the data for 33 years.
‘They missed it because they didn’t expect to get anything like it.’
Team: Other facilities around the world joined to confirm the discovery and study the object
The researchers say their discovery raises new questions about the structure of magnetism and may even shed light on the origin of mysterious phenomena such as fast radio bursts.
These strange bright flashes of light registered in the radio band of the electromagnetic spectrum appear temporarily and randomly from space.
They were first identified only 15 years ago but scientists never knew where they came from.
The researchers now want to make further observations to see if they can discover a similar stellar object to GPM J1839−10.
This could help them confirm once and for all that these mysterious objects are ultra-long-period magnets, or perhaps something more extraordinary.
Even with a link to extraterrestrials.
The new discovery was published in the journal Nature.
What are neutron stars?
Neutron stars are the collapsed, burned-out cores of dead stars.
When massive stars reach the end of their lives, their cores will collapse, blowing away the outer layers of the star.
It leaves behind an extremely dense object known as a neutron star, which squashes more mass than the Sun into the size of a city.
A neutron star’s mass is typically half a million times the mass of Earth, but they are about 20 kilometers (12 mi) across.
A handful of material from this star would weigh as much as Mount Everest.
They are very hot, perhaps a million degrees, highly radioactive, and have incredibly strong magnetic fields.
According to Professor Patrick Sutton, Head of Gravitational Physics at Cardiff University, this makes them some of the most hostile environments in the universe today.
Dense objects, especially their cores, are key to our understanding of the heavy elements in the universe.