Feeds

Boffins bend space and time to measure neutron star

Einstein shouts 'told you so', through tear in space-time

Next gen security for virtualised datacentres

Astronomers have caught three neutron stars in the act of distorting space-time, just as Einstein predicted. Bendy space-time has been seen around black holes before, but this is the first time astronomers have seen it around any other body.

Sudip Bhattacharyya and Tod Strohmayer, both of NASA’s Goddard Space Flight Center, turned the XMM-Newton observatory to a binary system called Serpens-1, whose neutron star has a disc of hot iron atoms whirling around just above its surface at around 40 per cent of the speed of light.

Artist's concept of a rare explosion on a neutron star. Credit: NASA/Dana Berry

The NASA team studied the line these atoms produce in the emission spectrum it produces, and discovered that the line is not clean, but smudged asymmetrically by a combination of its relativistic velocity and the effect of the neutron star's powerful gravitational field.

"We have seen these asymmetric lines from many black holes, but this is the first confirmation that neutron stars can produce them as well. It shows that the way neutron stars accrete matter is not very different from that of black holes, and gives us a new tool to probe Einstein’s theory," says Strohmayer.

A neutron star has such a strong gravitational field because, as the name suggests, it is formed entirely of neutrons. One is formed when a star of more than 8 times the sun's mass exhausts its supply of hydrogen and helium, and starts to burn heavier and heavier atoms, until all that is left is its iron core.

When it runs out of fuel, the weight of the star is such that it collapses inwards, fusing the protons and electrons in the iron to form neutrons. The star has now effectively become a truly gigantic atomic nucleus. It holds roughly one and a half times the matter as our own sun, but crammed into a sphere of just a 20 - 30km radius. It is so dense, a cupful would weigh the same as Mount Everest.

The pair of scientists has already confirmed their work with another research group. Working in a group led by Edward Cackett and Jon Miller of the University of Michigan, they used Suzaku’s superb spectral capabilities to survey three neutron-star binaries: Serpens X-1, GX 349+2, and 4U 1820-30.

The Suzaku data revealed a nearly identical iron line in Serpens-1, and similarly skewed lines in the other two binaries.

This team observed a nearly identical iron line in Serpens X-1, confirming the XMM-Newton result. It detected similarly skewed iron lines in the other two systems as well.

Cackett explains that the work has given researchers another tool to deploy in their study of the stars.

"We’re seeing the gas whipping around just outside the neutron star’s surface. And since the inner part of the disc obviously cannot orbit any closer than the neutron star’s surface, these measurements give us a maximum size of the neutron star’s diameter," he says.

"The neutron stars can be no larger than 29 to 33 km across, results that agree with other types of measurements." ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
Our LOHAN spaceplane ballocket Kickstarter climbs through £8000
Through 25 per cent but more is needed: Get your UNIQUE rewards!
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
EOS, Lockheed to track space junk from Oz
WA facility gets laser-eyes out of the fog
Volcanic eruption in Iceland triggers CODE RED aviation warning
Lava-spitting Bárðarbunga prompts action from Met Office
LOHAN Kickstarter breaks NINETEEN THOUSAND of your EARTH POUNDS
That's right, OVER 9,000 beer tokens - and counting
Major cyber attack hits Norwegian oil industry
Statoil, the gas giant behind the Scandie social miracle, targeted
prev story

Whitepapers

Endpoint data privacy in the cloud is easier than you think
Innovations in encryption and storage resolve issues of data privacy and key requirements for companies to look for in a solution.
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.
Advanced data protection for your virtualized environments
Find a natural fit for optimizing protection for the often resource-constrained data protection process found in virtual environments.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Next gen security for virtualised datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.