Feeds

Space watchers spot pulsar eating a star

Skeleton star gets gobbled

Secure remote control for conventional and virtual desktops

Astronomers using NASA's Swift and Rossi X-Ray Timing Explorer (RXTE) satellites have discovered a stellar skeleton, a remnant of a dying star that is being consumed by its pulsar companion. So little of the star's original material is left that it now barely masses more than Jupiter.

Artist depiction. A pulsar tears into a planet mass object. Credit: Aurore Simonnet, Sonoma State University

Artist depiction. A pulsar tears into a planet mass object.

Credit: Aurore Simonnet, Sonoma State University

The artist's impression shows material being torn from a tear drop shaped blob in the foreground, flowing in a stream into the pulsar in the upper right corner. The planet-sized collection of helium is all that remains of the star. As its outer layers are pulled away, the material builds into a disk around the pulsar. Eventually, this material produces an outburst that can be seen from Earth.

The light from such an outburst reached Earth this June, which is when astronomers became aware of the system, some 25,000 light years from our sun.

NASA says the SWIFT J1756.9-2508 system is one of the most bizarre objects ever discovered in space. The observations from the RXTE satellite suggest the pulsar, which contains roughly 1.4 solar masses, is about 10 miles in diameter, and is spinning 182.07 times per second.

"This means that the surface of the star is moving at about 7000 miles per second, or roughly four per cent the speed of light," said Deepto Chakrabarty, an associate professor of physics in MIT's Kavli Institute for Astrophysics and Space Research. "While we already know of several cases of pulsars that have consumed or vapourised most of the mass in their companion star, SWIFT J1756.9 is possibly the most extreme example."

The scientists describe the likely history of the system. It probably formed several billion years ago, and consisted of a seriously massive star and a smaller companion. The huge star would have burned itself out and gone supernova relatively quickly, leaving behind the pulsar.

As the smaller star aged, it began to swell up as its internal pressure grew. It enveloped the pulsar, draining orbital energy from the system and causing the two objects to draw slightly closer together. Now the pair are closer together than the Earth is to the Moon, and the smaller star orbits the pulsar once every 54 minutes or so.

The team at MIT says observations of the system provide "a rare opportunity for astronomers to examine how millisecond pulsars are spun up to such incredibly rapid speeds, and to determine their eventual fate". ®

Top 5 reasons to deploy VMware with Tegile

More from The Register

next story
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
Antarctic ice THICKER than first feared – penguin-bot boffins
Robo-sub scans freezing waters, rocks warming models
Your PHONE is slowly KILLING YOU
Doctors find new Digitillnesses - 'text neck' and 'telepressure'
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
The next big thing in medical science: POO TRANSPLANTS
Your brother's gonna die, kid, unless we can give him your, well ...
NASA launches new climate model at SC14
75 days of supercomputing later ...
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
prev story

Whitepapers

Why cloud backup?
Combining the latest advancements in disk-based backup with secure, integrated, cloud technologies offer organizations fast and assured recovery of their critical enterprise data.
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.
Designing and building an open ITOA architecture
Learn about a new IT data taxonomy defined by the four data sources of IT visibility: wire, machine, agent, and synthetic data sets.
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?