Feeds

Astronomers finger culprit in 1572 supernova

Star spotted fleeing the scene

  • alert
  • submit to reddit

Build a business case: developing custom apps

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
LOHAN packs bags for SPACEPORT AMERICA!
Spanish launch goes titsup, we're off to the US of A
Gigantic toothless 'DRAGONS' dominated Earth's early skies
Gummy pterosaurs outlived toothy competitors
'Leccy racer whacks petrols in Oz race
ELMOFO rakes in two wins in sanctioned race
Boffins ID freakish spine-smothered prehistoric critter: The CLAW gave it away
Bizarre-looking creature actually related to velvet worms
CRR-CRRRK, beep, beep: Mars space truck backs out of slippery sand trap
Curiosity finds new drilling target after course correction
Astronomers scramble for obs on new comet
Amateur gets fifth confirmed discovery
Boffins build CYBORG-MOTHRA but not for evil: For search & rescue
This tiny bio-bot will chew through your clothes then save your life
Vulture 2 takes a battering in 100km/h test run
Still in one piece, but we're going to need MORE POWER
What does a flashmob of 1,024 robots look like? Just like this
Sorry, Harvard, did you say kilobots or KILLER BOTS?
prev story

Whitepapers

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.
Top 10 endpoint backup mistakes
Avoid the ten endpoint backup mistakes to ensure that your critical corporate data is protected and end user productivity is improved.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
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.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.