Wave-catching scientists use radio telescope to receive signals coming from the centre of the galaxy

Scientists have discovered radio signals that seem to be coming from the centre of the Milky Way.

Several signals have been received in the past year but astronomers have not yet been able to identify the source.

Some experts believe the signals, collectively known as Askap J173608.2-321635 after their co-ordinates, represent part of a new class of stellar object, such as a newly formed star or planet.

An international team of scientists used a radio telescope known as the Australian Square Kilometre Array Pathfinder, or Askap, in Western Australia to research the object.

Their study was published this week in the Astrophysical

“We have been surveying the sky with Askap to find unusual new objects ... throughout 2020 and 2021,” said Tara Murphy, an astrophysics professor at the University of Sydney.

“Looking towards the centre of the galaxy, we found Askap J173608.2-321635. This object was unique in that it started out invisible, became bright, faded away and then reappeared. This behaviour was extraordinary.”

Astronomers study radio waves from space objects to unlock the secrets of the universe, such as flaring stars, pulsars – a dense type of spinning dead star – and fast radio bursts.

Researchers also used the MeerKAT radio telescope in South Africa to observe the signals for 15 minutes every few weeks and found their behaviour to be far different to any other space object.

They received six signals from the same direction over nine months last year.

“At first we thought it could be a pulsar, or else a type of star that emits huge solar flares,” said Ziteng Wang, a doctoral student at the University of Sydney and lead author of the study.

“But the signals from this new source don’t match what we expect from these types of celestial objects.”

A study published in the Nature Astronomy journal this week suggested hidden planets are the reason distant stars emit radio waves.

Researchers discovered the signals using the Low Frequency Array, a powerful radio telescope in the Netherlands.

“We’ve discovered signals from 19 distant red dwarf stars, four of which are best explained by the existence of planets orbiting them,” said Dr Benjamin Pope, a lecturer at University of Queensland and a co-author of the study.

“This discovery is an important step for radio astronomy and could potentially lead to the discovery of planets throughout the galaxy.

“We can’t be 100 per cent sure that the four stars we think have planets are indeed planet hosts, but we can say that a planet-star interaction is the best explanation for what we’re seeing.”