Feeds

Dim stars shed light on age of galaxy

Beryllium count gives the game away

  • alert
  • submit to reddit

Providing a secure and efficient Helpdesk

A group of astronomers working on the Very Large Telescope (VLT) in Chile have determined that the galaxy is 13.6bn years old.

Its calculation of the age of the Milky Way is based on observations of two very faint stars in a local globular cluster, the BBC reports. Globular clusters are very concentrated clusters of stars which orbit galaxies, and contain some of the oldest stars still burning.

By measuring the amount of beryllium in each of the stars, the astronomers could calculate their age, since the element forms at a constant rate as stars burn. The team made its observations ib the 8.2m Kuyen telescope that is part of the VLT, using the UV-Visual Echelle Spectrograph.

Incidentally, some scientists think globular clusters may actually be remnants of smaller "dwarf" galaxies, caught in the gravitational maw of their larger counterparts. The implications this theory may have for these calculations is unclear.

The team carefully selected the stars they would measure, known as A0228 and A2111 in the NGC 6397 globular cluster. Star selection is vital because beryllium will burn up if the star has become too hot, making it useless as a benchmark.

Smaller stars are best, but are difficult to observe because they are so faint. Many of the larger stars, which burn faster and hotter, have already reached the giant phase of their evolution.

It is well known that the stars in globular clusters were not the first stars that ever burned in our galaxy: they contain elements that need supernovae to form. However, this new research has allowed scientists to calculate the interval between the first (now extinct) generation of stars and the ones we can still observe today.

By adding this number to the age of the stars, as determined by stellar evolution models, the team determined that the galaxy is 13.6bn years old, give or take 800m years.

Daniele Galli of INAF-Observatorio di Arcetri in Florence, Italy, told the BBC: "This is the first time we have obtained an independent determination of this fundamental value." ®

Related stories

Hubble loses an eye
Boffins baffled by suburban quasars
NASA seeks Hubble robot rescue input

Internet Security Threat Report 2014

More from The Register

next story
MARS NEEDS WOMEN, claims NASA pseudo 'naut: They eat less
'Some might find this idea offensive' boffin admits
LOHAN crash lands on CNN
Overflies Die Welt en route to lively US news vid
Comet Siding Spring revealed as flying molehill
Hiding from this space pimple isn't going to do humanity's reputation any good
Experts brand LOHAN's squeaky-clean box
Phytosanitary treatment renders Vulture 2 crate fit for export
No sail: NASA spikes Sunjammer
'Solar sail' demonstrator project binned
Carry On Cosmonaut: Willful Child is a poor taste Star Trek parody
Cringeworthy, crude and crass jokes abound in Steven Erikson’s sci-fi debut
Origins of SEXUAL INTERCOURSE fished out of SCOTTISH LAKE
Fossil find proves it first happened 385 million years ago
Human spacecraft dodge COMET CHUNKS pelting off Mars
Odyssey orbiter yet to report, though - comet's trailing trash poses new threat
prev story

Whitepapers

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.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Three 1TB solid state scorchers up for grabs
Big SSDs can be expensive but think big and think free because you could be the lucky winner of one of three 1TB Samsung SSD 840 EVO drives that we’re giving away worth over £300 apiece.
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.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.