Feeds

Staring at the surface of an alien star

Squashed, fast and cool

Beginner's guide to SSL certificates

Scientists have taken the first ever pictures of the surface of an alien Sol-like sun.

Actual image returned by the interferometer. Credit: Ming Zhao, University of Michigan

The team, led by astronomers at the University of Michigan, made the observations of the relatively nearby (15 light years away) star Altair. They used four of the six telescopes at Georgia State University's Centre for High Angular Resolution Astronomy (CHARA) interferometric array on Mount Wilson, California.

Astronomers already knew Altair was oddly shaped: the star is 22 per cent wider than it is tall, thanks to the speed of its rotation. At its equator it is spinning 638,000mph, roughly 60 times faster than our our sun.

"It's really whipping around and that's why, of course, it's spread out like a twirling ball of pizza dough," said Monnier, an assistant professor of astronomy at the University of Michigan.

In 1924 astronomer Hugo von Zeipel predicted that rapidly spinning stars would bulge. He also speculated that their equators would be much cooler than their poles, by virtue of the greater distance from the heat of the solar core.

The new images are the first that confirm the idea, but also reveal more about this predicted variation in temperature across the surface: the bulge is much cooler than standard models had predicted.

"This image can only be made with a telescope the size of a football arena. I dare say that we may never create a single telescope mirror this large, but we can do this today with interferometry (a technique to resolve an image using multiple beams)," said Monnier.

The image has been made possible by recent advances in fibre optics. This allows the researchers to combine the images from each telescope in such a way as to clean up some of the distortion from the Earth's atmosphere.

Optical interferometry has been used recently to discover details on the surface of much larger stars: helium burning red giants, for example. But this is the first time anyone has produced images of the surface of a hydrogen burning star like our own. ®

Internet Security Threat Report 2014

More from The Register

next story
Renewable energy 'simply WON'T WORK': Top Google engineers
Windmills, solar, tidal - all a 'false hope', say Stanford PhDs
Bond villains lament as Wicked Lasers withdraw death ray
Want to arm that shark? Better get in there quick
The next big thing in medical science: POO TRANSPLANTS
Your brother's gonna die, kid, unless we can give him your, well ...
SEX BEAST SEALS may be egging each other on to ATTACK PENGUINS
Boffin: 'I think the behaviour is increasing in frequency'
NASA launches new climate model at SC14
75 days of supercomputing later ...
Britain's HUMAN DNA-strewing Moon mission rakes in £200k
3 days, and Kickstarter moves lander 37% nearer takeoff
Reuse the Force, Luke: SpaceX's Elon Musk reveals X-WING designs
And a floating carrier for recyclable rockets
Simon's says quantum computing will work
Boffins blast algorithm with half a dozen qubits
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.
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.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
The Heartbleed Bug: how to protect your business with Symantec
What happens when the next Heartbleed (or worse) comes along, and what can you do to weather another chapter in an all-too-familiar string of debilitating attacks?