Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



EXO WORLDS
Mysterious ripples found racing through planet-forming disc
by Staff Writers
Paris (ESA) Oct 08, 2015


Using images from the NASA/ESA Hubble Space Telescope and ESO's Very Large Telescope, astronomers have discovered fast-moving wave-like features in the dusty disc around the nearby star AU Microscopii. These odd structures are unlike anything ever observed, or even predicted, before now. Image courtesy ESO, NASA and ESA. For a larger version of this image please go here.

Using images from the NASA/ESA Hubble Space Telescope and ESO's Very Large Telescope, astronomers have discovered never-before-seen structures within a dusty disc surrounding a nearby star. The fast-moving wave-like features in the disc of the star AU Microscopii are unlike anything ever observed, or even predicted, before now. The origin and nature of these features present a new mystery for astronomers to explore. The results are published in the journal Nature on 8 October 2015.

AU Microscopii, or AU Mic for short, is a young, nearby star surrounded by a large disc of dust. Studies of such debris discs can provide valuable clues about how planets, which form from these discs, are created.

Astronomers have been searching AU Mic's disc for any signs of clumpy or warped features, as such signs might give away the location of possible planets. And in 2014 they used the powerful high-contrast imaging capabilities of ESO's newly installed SPHERE instrument, mounted on the Very Large Telescope for their search - and discovered something very unusual.

"Our observations have shown something unexpected," explains Anthony Boccaletti of the Observatoire de Paris, France, lead author on the paper. "The images from SPHERE show a set of unexplained features in the disc which have an arch-like, or wave-like, structure, unlike anything that has ever been observed before."

Five wave-like arches at different distances from the star show up in the new images, reminiscent of ripples in water. After spotting the features in the SPHERE data the team turned to earlier images of the disc taken by the NASA/ESA Hubble Space Telescope in 2010 and 2011 to see whether the features were also visible in these. They were not only able to identify the features on the earlier Hubble images - but they also discovered that they had changed over time. It turns out that these ripples are moving - and very fast!

"We reprocessed images from the Hubble data and ended up with enough information to track the movement of these strange features over a four-year period," explains team member Christian Thalmann (ETH Zurich, Switzerland). "By doing this, we found that the arches are racing away from the star at speeds of up to about 40 000 kilometres/hour!"

The features further away from the star seem to be moving faster than those closer to it. At least three of the features are moving so fast that they could well be escaping from the gravitational attraction of the star. Such high speeds rule out the possibility that these are conventional disc features caused by objects - like planets - disturbing material in the disc while orbiting the star. There must have been something else involved to speed up the ripples and make them move so quickly, meaning that they are a sign of something truly unusual.

"Everything about this find was pretty surprising!" comments co-author Carol Grady of Eureka Scientific, USA. "And because nothing like this has been observed or predicted in theory we can only hypothesise when it comes to what we are seeing and how it came about."

The team cannot say for sure what caused these mysterious ripples around the star. But they have considered and ruled out a series of phenomena as explanations, including the collision of two massive and rare asteroid-like objects releasing large quantities of dust, and spiral waves triggered by instabilities in the system's gravity.

But other ideas that they have considered look more promising.

"One explanation for the strange structure links them to the star's flares. AU Mic is a star with high flaring activity - it often lets off huge and sudden bursts of energy from on or near its surface," explains co-author Glenn Schneider of Steward Observatory, USA. "One of these flares could perhaps have triggered something on one of the planets - if there are planets - like a violent stripping of material which could now be propagating through the disc, propelled by the flare's force."

"It is very satisfying that SPHERE has proved to be very capable at studying discs like this in its first year of operation," adds Jean-Luc Beuzit, who is both a co-author of the new study and also led the development of SPHERE itself.

The team plans to continue to observe the AU Mic system with SPHERE and other facilities, including ALMA, to try to understand what is happening. But, for now, these curious features remain an unsolved mystery.

This research was presented in a paper entitled "Fast-Moving Structures in the Debris Disk Around AU Microscopii", to appear in the journal Nature on 8 October 2015.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Hubble Information Centre at ESA
Lands Beyond Beyond - extra solar planets - news and science
Life Beyond Earth






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
EXO WORLDS
The Most Stable Source of Light in the World
Geneva, Switzerland (SPX) Oct 02, 2015
In order to be able to detect planets comparable to Earth, the CHEOPS satellite, which will be sent into orbit at the end of 2017, must be able to measure the luminosity of a star with inimitable accuracy. In order to test CHEOPS detectors researchers need a stable source of light. However there was no instrument capable of producing a light source with sufficient stability to be used as a ... read more


EXO WORLDS
Lunar Pox

Space startup confirms plans for robotic moon landings

Asteroids found to be the moon's main 'water supply'

Russian scientist hope to get rocket fuel, water, oxygen from Lunar ice

EXO WORLDS
NASA unveils missing pieces in journey to Mars

Curiosity Rover Team Confirms Ancient Lakes on Mars

MRO imagery reveals Red Planet's stressed substrate

Geology Award Going to Mars Landing Site Expert at JPL

EXO WORLDS
NASA Tournament Lab to collaborate on human habitation in space

NASA Prepares to Test Orion Service Module

NASA announces Challenge for Methods of Assessing Damage to Space Suits

Selected NASA Discovery Missions Include Three With PSI Ties

EXO WORLDS
Latest Mars film bespeaks potential of China-U.S. space cooperation

Exhibition on "father of Chinese rocketry" opens in U.S.

The First Meeting of the U.S.-China Space Dialogue

China's new carrier rocket succeeds in 1st trip

EXO WORLDS
Meet the International Docking Adapter

NASA extends Boeing contract for International Space Station

Russian launches cargo spaceship to the ISS

Successful re-entry of H-II Transfer Vehicle Kounotori5

EXO WORLDS
Both passengers for next Ariane 5 mission arrive in French Guiana

Arianespace signs ARSAT to launch a new satellite for Argentina

Ariane 5 orbits Sky Muster and ARSAT-2

A satellite launcher for the Middle East

EXO WORLDS
Mysterious ripples found racing through planet-forming disc

The Most Stable Source of Light in the World

Earth-class planets likely have protective magnetic fields, aiding life

Stellar atmosphere can be used to predict the composition of rocky exoplanets

EXO WORLDS
More students earning statistics degrees - but not enough

3-D printing techniques help surgeons carve new ears

Caution: Shrinks when warm

Flipping molecular attachments amps up activity of CO2 catalyst




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement