Feeds

Speedy cannibal pulsar caught in the act

One companion star, to go

High performance access to file storage

European and US space agency astronomers have spotted a particularly fast-spinning pulsar that is in the process of gobbling up its companion star.

The sighting is further supporting evidence for the hypothesis that binary pulsars evolve into isolated, fast-spinning pulsars, and actually increase their spin rate by chowing down on a nearby star. This is the first system in which the pulsar has been caught in the act of speeding itself up.

"We're getting to the point where we can look at any fast-spinning, isolated pulsar and say, 'That guy used to have a companion'," said Dr Maurizio Falanga, who led the Integral observations, at the Commissariat à l'Energie Atomique (CEA) in Saclay, France.

The researchers describe it as 'an evolutionary step' between a stately life as a binary pulsar, spinning around once or twice a second and the fast lane of being an 'X-ray millisecond pulsar'. These rotate several hundred times a second, and this particular pulsar, with a period of 1.67 milliseconds, is one of the fastest known.

The pulsar was identified by the European Space Agency's (ESA) Integral space observatory, and NASA's Rossi X-ray Timing Explorer spacecraft. It was picked up by Integral during a routine scan of the outer edges of the Milky Way. The following day, NASA observers used Rossi to work out just how fast the object was spinning.

Rossi also revealed that most of the pulsar's companion has already been swallowed - the star could now be as small as 40 Jupiter masses. The two bodies orbit each other so tightly, once every two-and-a-half hours, that both could fit neatly inside the radius of our sun.

A pulsar is a rotating neutron star, a remnant of the explosive death throes of a star at least eight times as massive as our own sun. In general, a pulsar is about the same mass as our sun, but is a mere 20km or so across. When they are born, they tend to spin very rapidly, courtesy of conservation of angular momentum, but they slow down over the course of a hundred thousand years or so.

Isolated pulsars may be condemned to a sluggish future, but those living in binary systems can halt their decline by devouring a neighbour. As the gas is torn from the companion, the pulsar spin-rate increases. As the gas from the companion crashes into the neutron star, it releases huge amounts of energy in the form of X-ray and gamma radiation.

"This object was about ten times more energetic than what is usually observed for similar sources," said Falanga. He added that "only some kind of monster emits at these energies", which correspond to a temperature of almost a billion degrees. ®

High performance access to file storage

More from The Register

next story
Fancy joining Reg hack on quid-a-day challenge?
Recruiting now for charity starvation diet
Red-faced LOHAN team 'fesses up in blown SPEARS fuse fiasco
Standing in the corner, big pointy 'D' hats
KILLER SPONGES menacing California coastline
Surfers are safe, crustaceans less so
LOHAN's Punch and Judy show relaunches Thursday
Weather looking good for second pop at test flights
Discovery time for 200m WONDER MATERIALS shaved from 4 MILLENNIA... to 4 years
Alloy, Alloy: Boffins in speed-classification breakthrough
Elon Musk's LEAKY THRUSTER gas stalls Space Station supply run
Helium seeps from Falcon 9 first stage, delays new legs for NASA robonaut
Top Secret US payload launched into space successfully
Clandestine NRO spacecraft sets off on its unknown mission
New FEMTO-MOON sighted BIRTHING from Saturn's RING
Icy 'Peggy' looks to be leaving the outer rings
prev story

Whitepapers

Top three mobile application threats
Learn about three of the top mobile application security threats facing businesses today and recommendations on how to mitigate the risk.
Combat fraud and increase customer satisfaction
Based on their experience using HP ArcSight Enterprise Security Manager for IT security operations, Finansbank moved to HP ArcSight ESM for fraud management.
The benefits of software based PBX
Why you should break free from your proprietary PBX and how to leverage your existing server hardware.
Five 3D headsets to be won!
We were so impressed by the Durovis Dive headset we’ve asked the company to give some away to Reg readers.
SANS - Survey on application security programs
In this whitepaper learn about the state of application security programs and practices of 488 surveyed respondents, and discover how mature and effective these programs are.