Birth of black hole kills the radio star

Share via AddThis
Posted December 23, 2013

Astronomers led by a Curtin University researcher have discovered a new population of exploding stars that “switch off” their radio transmissions before collapsing into a Black Hole.

These exploding stars use all of their energy to emit one last strong beam of highly energetic radiation – known as a gamma-ray burst – before they die.

Up until now, it was thought all gamma-ray bursts were followed by a radio afterglow – a premise that a team of Australian astronomers of the Centre for All-sky Astrophysics (CAASTRO) at Curtin University and the University of Sydney originally set out to prove correct.

“But we were wrong. After studying an ultra-sensitive image of gamma-ray bursts with no afterglow, we can now say the theory was incorrect and our telescopes have not failed us,” lead researcher and Curtin research fellow Dr Paul Hancock said.

The technique used to create the ultra-sensitive image was recently published in The Astrophysical Journal.

It allowed for the stacking of 200 separate observations on top of each other to re-create the image of a gamma-ray burst in much better quality – yet, no trace of a radio afterglow was found.

“In our research paper we argue that there must be two distinct types of gamma-ray burst, likely linked to differences in the magnetic field of the exploding star,” Dr Hancock said.

“Gamma-ray bursts are thought to mark the birth of a Black Hole or Neutron Star – both of which have super-dense cores. But Neutron Stars have such strong magnetic fields (a million times stronger than those of Black Holes) that producing gamma-rays are more difficult.

“We think that those stars that collapse to form a Neutron Star have energy left over to produce the radio afterglow whereas those that become Black Holes put all their energy into one final powerful gamma-ray flash.”

New work is underway to test the team’s theory and to see if there are other subtle ways in which the two types of bursts differ.

“We now have to take a whole new look at gamma-ray bursts – so far this work has shown that being wrong is sometimes more interesting than being right,” Dr Hancock said.

Telescope facilities such as the Australia Telescope Compact Array in northern New South Wales and the Karl Jansky Very Large Array in the US both have observing programs to search for gamma-ray burst afterglows and have been recently upgraded to increase their sensitivity.

The research report can be found at

Source: Curtin University

48,941 science & technology articles


Our Articles (see all)

General News

Follow us

Facebook   Twitter   Pinterest   StumbleUpon   Plurk
Google+   Tumblr   Delicious   RSS   Newsletter via Email

Featured Video (see all)

In control skin from the hip (A) and normal-appearing skin from the abdomen (B), elastic fibers responsible

for skin elasticity are intact, forming an intricate mesh-like network. In stretch marks that have recently

formed during pregnancy (C), elastic fibers are lost and replaced by disorganized, thin fibrils, or “strands,”

that persist without forming a normal elastic network. The middle and bottom panels magnify the identified

areas of the top panels.
Stretch mark science: What happens to your skin when pregnancy gives you a stretch mark?
Don’t believe the hype when you see those creams and ointments promising to prevent or reduce pregnancy stretch…

Featured Image (see all)

Scientists Set Quantum Record by Using Photons to Ferry Data between Electrons 1.2 Miles Apart
Quantum entanglement is the observed phenomenon of two or more particles that are connected, even over thousands of…