Space

August 5, 2013

NASA’s Hubble finds telltale fireball after gamma ray burst

nasa-hubble

NASA’s Hubble Space Telescope recently provided the strongest evidence yet that short-duration gamma ray bursts are produced by the merger of two small, super-dense stellar objects.

The evidence is in the detection of a new kind of stellar blast called a kilonova, which results from the energy released when a pair of compact objects crash together. Hubble observed the fading fireball from a kilonova last month, following a short gamma ray burst in a galaxy almost 4 billion light-years from Earth. A kilonova had been predicted to accompany a short-duration GRB, but had not been seen before.

“This observation finally solves the mystery of the origin of short gamma ray bursts,” said Nial Tanvir of the University of Leicester in the United Kingdom. Tanvir lead a team of researchers using Hubble to study the recent short-duration GRB. “Many astronomers, including our group, have already provided a great deal of evidence that long-duration gamma ray bursts (those lasting more than two seconds) are produced by the collapse of extremely massive stars. But we only had weak circumstantial evidence that short bursts were produced by the merger of compact objects. This result now appears to provide definitive proof supporting that scenario.”

The team’s results appeared Aug. 3 in a special online edition of the journal Nature.

A kilonova is about 1,000 times brighter than a nova, which is caused by the eruption of a white dwarf.  The self-detonation of a massive star, a supernova, can be as much as 100 times brighter than a kilonova. Gamma ray bursts are mysterious flashes of intense high-energy radiation that appear from random directions in space. Short-duration blasts last at most a few seconds, but they sometimes produce faint afterglows in visible and near-infrared light that continue for several hours or days. The afterglows have helped astronomers determine that GRBs lie in distant galaxies.

Astrophysicists have predicted short-duration GRBs are created when a pair of super-dense neutron stars in a binary system spiral together. This event happens as the system emits gravitational radiation, creating tiny waves in the fabric of space-time. The energy dissipated by the waves causes the two stars to sweep closer together. In the final milliseconds before the explosion, the two stars merge into a death spiral that kicks out highly radioactive material. This material heats up and expands, emitting a burst of light.

In a recent science paper Jennifer Barnes and Daniel Kasen of the University of California at Berkeley and the Lawrence Berkeley National Laboratory presented new calculations predicting how kilonovas should look. They predicted the same hot plasma producing the radiation also will block the visible light, causing the gusher of energy from the kilonova to flood out in near-infrared light over several days.

An unexpected opportunity to test this model came June 3 when NASA’ s Swift space telescope picked up the extremely bright gamma ray burst, cataloged as GRB 130603B. Although the initial blast of gamma rays lasted just one-tenth of a second, it was roughly 100 billion times brighter than the subsequent kilonova flash.

From June 12-13, Hubble searched the location of the initial burst, spotting a faint red object. An independent analysis of the data from another research team confirmed the detection. Subsequent Hubble observations July 3 revealed the source had faded away, therefore providing the key evidence the infrared glow was from an explosion accompanying the merger of two objects.

 




All of this week's top headlines to your email every Friday.


 
 

 

NASA airborne campaigns tackle climate questions from Africa to Arctic

NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into how different aspects of the interconnected Earth system influence climate change. NASA photograph The DC-8 airborne laboratory is one of several NASA aircraft that will fly in support of five new investigations into...
 
 
NASA photograph by Aubrey Gemignani

New crew arrives at space station to continue scientific research

NASA photograph by Aubrey Gemignani The Soyuz TMA-15M rocket launches from the Baikonur Cosmodrome in Kazakhstan Nov. 24, 2014 carrying Expedition 42 Soyuz Commander Anton Shkaplerov of the Russian Federal Space Agency (Roscosm...
 
 
nasa-cube

NASA opens Cube Quest Challenge for largest-ever prize of $5 million

Registration now is open for NASA’s Cube Quest Challenge, the agency’s first in-space competition that offers the agency’s largest-ever prize purse. Competitors have a shot at a share of $5 million in prize money and ...
 

 
Lockheed Martin image

Ball Aerospace equips Orion mission with key avionics, antenna hardware

Lockheed Martin image Ball Aerospace & Technologies Corp. is providing the phased array antennas and flight test cameras to prime contractor Lockheed Martin for Orion’s Exploration Flight Test-1 (EFT-1), which is an u...
 
 
NASA photograph

NASA announces new opportunities for public participation in asteroid grand challenge

NASA photograph Team NOVA Took the Winning Hackathon Prize.   Ten new projects are providing opportunities for the public to participate in NASA’s Asteroid Grand Challenge, which accelerates the agency’s astero...
 
 
XCOR Aerospace photograph by Mike Massee

XCOR Aerospace announces latest milestone in ULA program

XCOR Aerospace photograph by Mike Massee The XCOR-ULA XR-5H25 LOX-Hydrogen Rocket Engine, fed by XCOR’s proprietary rocket propellant piston pump technology. MOJAVE, Calif. XCOR Aerospace announced Nov. 20 it has complete...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>