Radio signals detected from Dead Star nearly 3 billion light-years away

Radio signals detected from Dead Star nearly 3 billion light-years away

Radio signals detected from Dead Star nearly 3 billion light-years away

Mysterious radio signals have been detected emanating from a dead star nearly three billion light-years from Earth.

They are emitted by a “magnetar” – which has the most powerful known magnetic fields in the universe – or a giant sun that has gone supernova.

The strange object, described in the journal Nature, emits a beam of radiation that crosses our line of sight.

Magnetars are a type of neutron star that forms after a supernova and is subject to violent outbursts that last only a fraction of a second.

They can hold up to half a million times the mass of Earth, in a diameter of just 20.4 miles.

Active galaxy NGC 1275 in 2008
This handout image of the giant, active galaxy NGC 1275, acquired on August 21, 2008, was captured in July and August 2006 using NASA/ESA Hubble Space Telescope’s Advanced Camera for Surveys.
NASA/ESA via Getty Images/Zenger

Astronomers say this is only the second example of a highly active, repeating Fast Radio Burst (FRB), shedding new light on the nature of intergalactic space.

They used the Karl G. Jansky Very Large Array (VLA) and other National Science Foundation telescopes to study the object, which was first discovered in 2019.

Observations in 2020 determined the object’s location, leading to its identification in the outskirts of a dwarf galaxy far, far, far away.

The VLA data also showed that it continually emits weaker radio waves between bursts.

Andromeda Spiral Galaxy Hubble Space Telescope
Released on May 8, 2003, this NASA image was created from 250 individual images taken by the Hubble Space Telescope from December 2, 2002 to January 11, 2003 and shows the nearest neighboring spiral galaxy, Andromeda.
NASA/Getty Images via Zenger

Co-author Professor Casey Law, of the California Institute of Technology, said: “Those characteristics make it very similar to the very first FRB that was ranked — also by the VLA — in 2016.”

This development was a major breakthrough and provided the first information about the environment and distance of an FRB.

But the combination of repeating bursts and sustained inter-burst radio emissions, originating from a compact area, set the 2016 object, FRB 121102, apart from all other known FRBs thus far.

Law said, “Now we have two like this one, and that raises some important questions.”

The differences between FRB 190520 and FRB 121102 and all others reinforce a previously suggested possibility that there could be two different types of FRBs.

Co-author Kshitij Aggarwal, a graduate student at West Virginia University (WVU), said, “Are those who repeat different from those who don’t? What about the ongoing radio emission — is that common?”

The international team says there could be two different mechanisms that produce FRBs or that the objects they produce may act differently at different stages of their evolution.

Large Magellanic Cloud
This image, taken by the Hubble Telescope on July 10, 2001, shows two clusters of stars, called NGC 1850, located in a neighboring galaxy called the Large Magellanic Cloud.
NASA/Getty Images via Zenger

Leading candidates for the sources are super-dense neutron stars left over after a supernova, or neutron stars with ultra-strong magnetic fields, called magnetars.

A feature of FRB 190520 casts doubt on the usefulness of FRBs as tools for studying the material between them and the Earth.

Astronomers often analyze the effects of intervening material on the radio waves emitted by distant objects to learn more about that tenuous material itself.

Such an effect occurs when radio waves pass through space containing free electrons.

In that case, high-frequency waves travel faster than low-frequency waves.

SN 2006gy
In this handout provided by NASA, an artist’s interpretation illustrates the explosion of SN 2006gy, a massive star in what scientists call the brightest supernova ever recorded.
Photo illustration by M. Weiss/NASA/CXC via Getty Images/Zenger

This effect, called dispersion, can be measured to determine the density of electrons in the space between the object and the Earth, or, if the electron density is known or assumed, give a rough estimate of the distance to the object.

The distance from Earth was calculated by the Doppler shift of light from the galaxy caused by the expansion of the universe, placing the galaxy nearly three billion light-years from Earth.

The astronomers speculated that FRB 190520 could be a “newborn,” still surrounded by dense material expelled from the supernova explosion that left the neutron star.

As that material eventually disappears, so would the propagation of the burst signals.

In the scenario, the repetitive bursts may also be a feature of younger FRBs and decrease with age.

Co-author Sarah Burke-Spolaor, who teaches at WVU, added: “The FRB field is moving very fast right now and new discoveries are coming out every month.

“However, big questions still remain, and this object gives us challenging clues about those questions.”

This story was provided to Newsweek by Zenger News.