Feeds

Astronomers finger culprit in 1572 supernova

Star spotted fleeing the scene

  • alert
  • submit to reddit

5 things you didn’t know about cloud backup

An international team of astronomers has identified the surviving companion star to the 1572 supernova explosion witnessed by the Danish astronomer Tycho Brahe. This looks to be the first piece of direct, physical evidence that supports the long-standing theory of how this particular type of supernova explosion actually occurs.

Supernovae are classified according to the elements that can be identified in their spectra. Broadly, they are split into Type I and Type II. Type II has a so-called Balmer line, a spectral line indicating a particular transition within the hydrogen atom, while Type I does not. Each main type is further divided — Type I into a, b or c classifications. Type Ia supernovae are characterised by strong silicon emission lines.

Type Ia supernovae, of which the Tycho Brahe explosion is an example, occur when a white dwarf star begins to suck in matter from a companion star, usually when it reaches its red-giant stage. This continues until the white dwarf star becomes so massive that its internal pressure is no longer sufficient to support the outer layers, and the star collapses in on itself. The threshold is known as the Chandrasekar limit, after the Indian physicist who first calculated it.

In the case of the 1572 explosion, when the white dwarf exploded, the companion star was released from its gravitational influence like a stone being thrown by a sling. It went hurtling off into space with its orbital velocity being retained. This is what alerted the astronomers to its existence.

This new research, published today in the journal Nature, identifies the likely companion star to the now-exploded white dwarf. The team studied the star for seven years, using a variety of telescopes, including Hubble, to track how it is moving against the background. Their results show that it is moving three times faster than anything else in the region.

Pilar Ruiz-Lapuente of the University of Barcelona, led the research. She notes that this is the first evidence of any specific type of companion star: "Here we have identified a clear path: the feeding star is similar to our sun, but slightly older," she said.

However, there are alternative suggestions, both as to how the star could be moving so fast, and of how a type Ia supernova can occur. It is possible that the star is falling to the area from another region known as the galactic halo. Type Ia supernovae can also be generated by a double white dwarf system in which the stars fall into one another, and their combined mass sends them over the Chandrasekar limit. ®

Related stories

X-ray fireworks could signal supernovae
Smart telescopes probe galactic mysteries
Astronomers probe Cassiopeia's secrets

Secure remote control for conventional and virtual desktops

More from The Register

next story
Boffins attempt to prove the UNIVERSE IS JUST A HOLOGRAM
Is this the real life? Is this just fantasy?
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
Software bug caught Galileo sats in landslide, no escape from reality
Life had just begun, code error means Russia's gone and thrown it all away
LOHAN tunes into ultra long range radio
And verily, Vultures shall speak status unto distant receivers
NASA to reformat Opportunity rover's memory from 125 million miles away
Interplanetary admins will back up data and get to work
SpaceX prototype rocket EXPLODES over Texas. 'Tricky' biz, says Elon Musk
No injuries or near injuries. Flight stayed in designated area
Galileo, Galileo! Galileo, Galileo! Galileo fit to go. Magnifico
I'm just a poor boy, nobody loves me. But at least I can find my way with ESA GPS by 2017
prev story

Whitepapers

Gartner critical capabilities for enterprise endpoint backup
Learn why inSync received the highest overall rating from Druva and is the top choice for the mobile workforce.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Rethinking backup and recovery in the modern data center
Combining intelligence, operational analytics, and automation to enable efficient, data-driven IT organizations using the HP ABR approach.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.