Feeds

Supersized stellar blackhole prompts model rewrite

Boffins go back to the drawing board

The Power of One Infographic

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. ®

Eight steps to building an HP BladeSystem

More from The Register

next story
Malaysian Airlines flight MH17 claimed lives of HIV/AIDS cure scientists
Researchers, advocates, health workers among those on shot-down plane
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Mwa-ha-ha-ha! Eccentric billionaire Musk gets his PRIVATE SPACEPORT
In the Lone Star State, perhaps appropriately enough
MARS NEEDS OCEANS to support life - and so do exoplanets
Just being in the Goldilocks zone doesn't mean there'll be anyone to eat the porridge
Diary note: Pluto's close-up is a year from … now!
New Horizons is less than a year from the dwarf planet
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.