Mysterious rare five-hour space explosion explained

The X-ray image from the Swift X-ray Telescope of the gamma-ray burst GRB 130925. 

The white object in the center is the gamma-ray burst. 

The large diffuse region to the right is a cluster of galaxies. 

The other objects are X-ray-emitting celestial objects, most likely supermassive black holes at the centers of distant galaxies. 

The full image is approximately the size of the full moon. 

Credit: Phil Evans/ University of Leicester

Next week in St. Petersburg, Russia, scientists on an international team that includes Penn State University astronomers will present a paper that provides a simple explanation for mysterious ultra-long gamma-ray bursts, a very rare form of the most powerful explosions in the universe.

"The recent discovery of ultra-long gamma-ray bursts raised questions about whether some new physics is required to explain them, but our work suggests a much simpler explanation," said David Burrows, a Penn State professor of astronomy and astrophysics.

"Our analysis reveals that these rare gamma-ray bursts, which can last for hours, can be explained as standard explosions occurring in a region with a low density of matter that is located behind a cloud of dust when viewed from Earth."

Dick Willingale, an astronomer at the University of Leicester and a co-author of the study, said, "Not only is this result significant scientifically, but it shows the importance of international collaborations to build observatories, and of sharing information between those observatories."

Burrows is the lead scientist for the X-Ray Telescope on board the Swift satellite, one of two space observatories that the scientists used to collect data from the gamma-ray burst named GRB 130925A, which they observed last year while the energy from its explosion streamed toward Earth for more than five hours.

Swift is a NASA-led collaboration with Penn State in the United States, the University of Leicester and University College-London in the United Kingdom, and the Italian space agency and Brera Observatory in Italy.

The scientists also observed the ultra-long gamma-ray burst with the US/Russian satellite Konus-Wind.

"We could not have reached our conclusions without the Swift and Konus teams working together," Willingale said.

Burrows said it is not surprising that some gamma-ray bursts occur in a low-density region, nor is it surprising when one occurs behind a dust cloud.

"Our analysis of the observations from the two observatories shows that these two conditions existing simultaneously can explain our observations of the ultra-long gamma-ray burst GRB 130925A," Burrows said.

"One reason that these results are satisfying is that scientists generally prefer to find the simplest explanations for mysterious phenomena," he said.

Astronomers detect Light from Gamma Ray Burst from huge explosion 12 billion years ago

Light from the explosion 12 billion years ago of a massive star at the end of its life reached Earth recently. 

An image of its peak afterglow, circled with blue and yellow, was captured by Southern Methodist University's ROTSE-IIIb telescope at McDonald Observatory, Fort Davis, Texas. 

A bright star sits alongside the afterglow from GRB 140419A. 

Credit: ROTSE-IIIb, SMU

Known as a gamma-ray burst, the intense light captured in the night sky resulted from one of the biggest and hottest explosions in the universe, occurring shortly after the Big Bang.

Intense light from the enormous explosion of a star more than 12 billion years ago, shortly after the Big Bang, recently reached Earth and was visible in the sky.

Known as a gamma-ray burst, light from the rare, high-energy explosion traveled for 12.1 billion years before it was detected and observed by a telescope owned by Southern Methodist University, Dallas.


Gamma-ray bursts (GRBs) are believed to be the catastrophic collapse of a star at the end of its life. SMU physicists report that their telescope was the first on the ground to observe the burst and to capture an image, said Farley Ferrante, a graduate student in SMU's Department of Physics, who monitored the observations along with two astronomers in Turkey and Hawaii.

Recorded as GRB 140419A by NASA's Gamma-ray Coordinates Network, the burst was spotted at 11 p.m. April 19 by SMU's robotic telescope, ROTSE-IIIb, at the McDonald Observatory in the Davis Mountains of West Texas.

Gamma-ray bursts (GRBs) are not well understood by astronomers, but they are considered important, Ferrante said.

"As NASA points out, gamma-ray bursts are the most powerful explosions in the universe since the Big Bang," he said. "These bursts release more energy in 10 seconds than our Earth's sun during its entire expected lifespan of 10 billion years."

Some of these gamma-ray bursts appear to be related to supernovae, and correspond to the end-of-life of a massive star, said Robert Kehoe, physics professor and leader of the SMU astronomy team.

"Gamma-ray bursts (GRBs) may be particularly massive cousins to supernovae, or may correspond to cases in which the explosion ejecta are more beamed in our direction. By studying them, we learn about supernovae," Kehoe said.

Scientists weren't able to detect optical light from gamma-ray bursts until the late 1990s, when telescope technology improved.

Among all lights in the electromagnetic spectrum, gamma rays have the shortest wavelengths and are visible only using special detectors.

SMU's ROTSE-IIIb at the McDonald Observatory, Fort Davis, Texas had the earliest and brightest observation from the ground of a gamma-ray burst that occurred more than 12 billion years ago. 

The telescope is part of the Robotic Optical Transient Search Experiment, which has telescopes in four locations on Earth to cover the entire sky in search of gamma-ray bursts. 

Credit: ROTSE Collaboration.

Gamma-ray bursts (GRBs) result from hot stars that measure as enormous as 50 solar masses. The explosion occurs when the stars run out of fuel and collapse in on themselves, forming black holes.

Outer layers detonate, shooting out material along the rotation axis in powerful, high-energy jets that include gamma radiation.

As the gamma radiation declines, the explosion produces an afterglow of visible optical light. The light, in turn, fades very quickly, said Kehoe.

Physicists calculate the distance of the explosion based on the shifting wavelength of the light, or redshift.

"The optical light is visible for anywhere from a few seconds to a few hours," Kehoe said. "Sometimes optical telescopes can capture the spectra."

"This allows us to calculate the redshift of the light, which tells us how fast the light is moving away from us. This is an indirect indication of the distance from us."

Cosmic explosion spotted in neighbouring galaxy - video

NASA's Swift satellite reported an enormous explosion occurred this morning at 8.15 AEST in our neighbouring galaxy, Andromeda. This explosion is known as a Gamma Ray Burst (GRB), one of the most powerful explosions in the Universe.

The exact cause is unknown but thought to be an explosion from when two Neutron Stars collide.

These Neutron Stars are the dead cores of massive stars, with the mass of our Sun crushed into the size of a small city. When they merge together, the explosion is so powerful it can be seen from across the Universe.

Swinburne University of Technology astronomer Dr Alan Duffy says these GRBs explosions are so large that if they occur within our galaxy they can potentially trigger mass extinctions on Earth.

"Telescopes around the world are currently trained on the Andromeda galaxy looking in all wavelengths of light to learn more about this once-in-a-lifetime event."

"The explosion seen in light will also potentially be visible in gravitational waves, a key prediction of Einstein, ending a long quest to detect these ripples in space time."

"Unfortunately the world-wide facility for detecting these events, LIGO, is currently shut down for an upgrade, missing out on the explosion and a potential Nobel Prize winning discovery."

This animation shows the merger of two neutron stars from a horizontal perspective. Theory predicts that these kinds of collisions would not produce a long afterglow because there isn't much "fuel" dust and gas from the objects and in the region to sustain an afterglow. 

Credit: NASA

"The night sky seen in high-energy light is continuously flashing as titanic explosions, bright enough to be seen from across the length of the Universe, erupt and travel to us. It's a violent world out there.

"The most astounding aspect of today is that colliding Neutron Stars exploded in less than a second, shining out in Gamma Rays which have travelled undisturbed for 2.5 million years until hitting NASA's Swift satellite, within minutes telescopes across the globe were tracking it and an hour later people around the world were following it on Twitter. It's been hectic.