Feeds

Astronomers: gamma ray death from above 'unlikely'

Don't panic

Remote control for virtualized desktops

A gamma-ray burst (GRB) in our galactic neighbourhood could decimate life, destroy the ozone layer and trigger drastic climate change. A new study of Hubble data, published in Nature, has found such a cosmic deathray scenario is less likely than previous doomsday predictions.

The radiation the international team investigated comes with some of the biggest star explosions in the universe – long GRBs, which occur when a core-collapse supernova triggers an even more violent explosion.

Supernovae occur all over the universe and throughout galaxies. The researchers were testing the assumption that the galaxies with most supernovae would suffer the most GRBs. Instead, they found that long GRBs tend to originate from the runts of the cosmic litter – small, faint, irregularly shaped galaxies (pictured below; crosshairs indicate locations of GRBs).

Gamma Ray Burst Host Galaxies

Our own Milky Way is a regular spiral, so GRB armageddon from a nearby star death is unlikely, they reckon. Out of 42 GRBs measured, the astronomers found just one in a Milky Way-like spiral.

Lead author Andrew Fruchter of the Space Telescope Science Institute said: “[GRBs] occurrence in small irregulars implies that only stars that lack heavy chemical elements tend to produce long-duration GRBs.”

Heavy elements are themselves produced in supernovae and have built up in the universe over time. The implication is that long GRBs are getting less common in the universe generally.

They also found that unlike standard supernovae, long GRBs are concentrated at their host galaxy's brightest region. Study co-author Andrew Levan explained: "The discovery that long-duration GRBs lie in the brightest regions of their host galaxies suggests that they come from the most massive stars – perhaps 20 or more times as massive as our Sun."

The team concludes that GRBs are "relatively rare" in the Milky Way. ®

Remote control for virtualized desktops

More from The Register

next story
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
I'll be back (and forward): Hollywood's time travel tribulations
Quick, call the Time Cops to sort out this paradox!
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
prev story

Whitepapers

Driving business with continuous operational intelligence
Introducing an innovative approach offered by ExtraHop for producing continuous operational intelligence.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Choosing a cloud hosting partner with confidence
Download Choosing a Cloud Hosting Provider with Confidence to learn more about cloud computing - the new opportunities and new security challenges.