Feeds

Supersized stellar blackhole prompts model rewrite

Boffins go back to the drawing board

The next step in data security

Researchers have located the most massive stellar black hole ever discovered, just three million light-years away in a nearby galaxy. The stellar remnant is in a binary system known as M33, orbiting a huge companion star. The researchers say the find is "intriguing", because of what it suggests about stellar evolution.

Composite visual and X-Ray image of M33-X-7

Composite visual and X-Ray image of M33-X-7.

A stellar black hole is what is left after the death-by-collapsing-core of a massive star. The star that formed this one must have been huge.

The scientists used the Chandra X-Ray observatory and the Gemini telescope on Mauna Kea in Hawaii to measure the mass of the black hole, and discovered the remnant still has 15.7 times the mass contained in our own modest, yellow sun. Its companion star is also a humdinger - checking in at roughly 70 solar masses, it is the largest known companion star to a black hole. Eventually it too will go supernova, leaving a binary system containing only black holes.

"This discovery raises all sorts of questions about how such a big black hole could have been formed," said Jerome Orosz of San Diego State University, lead author of a paper appearing in the 18 October issue of Nature.

Conventional models of black hole formation suggest that the star would have been much larger even than its 70-solar-mass companion. It would have been so big that its radius would have been larger than the current separation between the two bodies, NASA's boffins explain.

This means the two stars must have drawn closer together while sharing a common outer atmosphere. But if this were the case, according to conventional models, the black hole shouldn't have retained such a large mass.

Still, it did, so the models are being re-thought. The researchers say the star must have lost mass roughly 10 times more slowly than they expected before it exploded.

The discovery could help explain an incredibly bright supernova, observed in 2006. The progenitor of this supernova is thought to have been about 150 solar masses when it exploded, which would make more sense if more massive stars lose their mass more slowly.

The system is also interesting because it is an eclipsing black hole. This unusual property is what allowed researchers to make "unusually accurate" estimates of the mass of both the black hole and its companion. ®

Choosing a cloud hosting partner with confidence

More from The Register

next story
SCREW YOU, Russia! NASA lobs $6.8bn at Boeing AND SpaceX to run space station taxis
Musk charging nearly half as much as Boeing for crew trips
PORTAL TO ELSEWHERE scried in small galaxy far, far away
Supermassive black hole dominates titchy star formation
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Edge Research Lab to tackle chilly LOHAN's final test flight
Our US allies to probe potential Vulture 2 servo freeze
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
Cracked it - Vulture 2 power podule fires servos for 4 HOURS
Pixhawk avionics juice issue sorted, onwards to Spaceport America
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Storage capacity and performance optimization at Mizuno USA
Mizuno USA turn to Tegile storage technology to solve both their SAN and backup issues.
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?
Security and trust: The backbone of doing business over the internet
Explores the current state of website security and the contributions Symantec is making to help organizations protect critical data and build trust with customers.