Stellar explosions are most often associated with supernova, the spectacular deaths of stars. But new ALMA observations of the Orion Nebula complex provide insights into explosions at the other end of the stellar life cycle, star birth. Picture: J. Bally/H. Drass
ASTRONOMERS have captured the incredible moment two stars collided 500 years ago to cause a spectacular explosion still visible from Earth.
After a pair of adolescent protostars grazed each other, they triggered a powerful eruption, launching dust and gas into space at more than 150 kilometres per second.
The explosion released as much energy as our Sun emits over the course of 10 million years.
New images from the Atacama Large Millimeter/submillimeter Array (ALMA) have allowed astronomers to gain new insights into the relationship among partner stars.
The protostars formed more than 100,000 years ago in the Orion Molecular Cloud 1 (OMC-1), a dense star factory about 1500 light-years from Earth.
They latched onto each other gravitationally and gradually drew closer, before grazing each other or colliding.
Today, the remains of this spectacular explosion are still visible from Earth, as shown in the images published in the Astrophysical journal.
Astronomers captured these dramatic images of the remains of a 500-year-old explosion as they explored the firework-like debris from the birth of a group of massive stars, demonstrating that star formation can be a violent and explosive process too. Picture: J. Bally/H. DrassSource:Supplied
Lead author John Bally from the University of Colorado said: “What we see in this once calm stellar nursery is a cosmic version of a 4th of July fireworks display, with giant streamers rocketing off in all directions.”
Groups of stars such as those in OMC-1 are born when a cloud of gas hundreds of times more massive than our Sun begins to collapse under its own gravity.
In the densest regions, the early formations of stars begin and drift about randomly.
Over time, gravity can draw the formations towards the largest protostar, and if they become too close, violent interactions can occur.
According to the researchers, such explosions are expected to be relatively short lived, with the remnants __like those seen by ALMA lasting only centuries.
Groups of stars such as those in OMC-1 are born when a cloud of gas hundreds of times more massive than our Sun begins to collapse under its own gravity. Picture: J. Bally/H. DrassSource:Supplied
Dr Bally added: “Though fleeting, protostellar explosions may be relatively common.
“By destroying their parent cloud, as we see in OMC-1, such explosions may also help to regulate the pace of star formation in these giant molecular clouds.”
The team observed the aftermath of the explosion with the Gemini-South telescope in Chile.
Their images, taken in near infra-red, reveal the remarkable structure of the streamers, which extend nearly a light-year from end to end.
Hints of the explosion were first uncovered in 2009 with the Submillimeter Array in Hawaii.
But the new ALMA data provides much greater clarity, unveiling important details about the distribution and high-velocity motion of the carbon monoxide gas inside the streamers.
This helps astronomers understand the underlying force of the blast and the impact such events could have on star formation across the galaxy.
Dr Bally said: “People most often associate stellar explosions with ancient stars, __like a nova eruption on the surface of a decaying star or the even more spectacular supernova death of an extremely massive star.
“ALMA has given us new insights into explosions on the other end of the stellar life cycle, star birth.”
This article originally appeared on The Sun.
Seeing Stars51:52
Today's new telescopes are among the most advanced ever built: triumphs of ambition and design, engineered to function perfectly in some of the harshest places on Earth - and beyond.
- July 8th 2015
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