Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Stellar desk in wave-like motion

08.10.2015

Astronomers detect unusual structures in AU Microscopii

As many other stars, AU Microscopii is surrounded by a dust disk. Now researchers – including scientists from the Max Planck Institute for Astronomy in Heidelberg – have discovered unusual structures in this disk, which change over time.


Images showing the debris disk around the star AU Mic in 2010 (top, Hubble Space Telescope), 2011 (center, ditto) and 2014 (bottom, SPHERE instrument), including newly discovered fast-moving wave-like features. The black central circles show where the brilliant light of the central star has been blocked off to reveal the much fainter disc, and the position of the star is indicated schematically. The scale bar at the top of the picture indicates the diameter of the orbit of the planet Neptune in the Solar System (60 times the distance Earth-Sun, corresponding to 60 AU). Note that the brightness of the outer parts of the disc has been artificially brightened to reveal the faint structure.

© ESO, NASA & ESA

The scientists are still puzzling what this phenomenon, which had previously never been observed before, could be. Is it connected with the eruptions of the star AU Mic? Or possibly even with as of yet undetected planets circling within the dust disk?

The star AU Mic ("AU Microscopii") in the Southern constellation Microscope, which is less than 33 light-years from Earth, is surrounded by a sizable disk made of dust, which observers on Earth can see directly edge-on.

Now, the has been imaged in great detail using SPHERE, the newly installed exoplanet-and-disks imaging machine at ESO's Very Large Telescope, and previous data from the Hubble Space Telescope. For the first time, astronomers could not only identify sub-structures, but also reliably track changes within the disk: fast-moving, wave-like features that move outwards within the disk.

When the instrument team for SPHERE chose targets for their initial observations, AU Mic was a natural candidate. MPIA director Thomas Henning, who is part of the team that studied the disk, explains: “Right away, we noticed detailed structures in the disk – if you had told me a few years ago that we would be able to image disks in such detail, I wouldn't have believed you. We compared these structures with images taken by a number of colleagues and myself using the Hubble Space Telescope in 2010 and 2011.”

Henning continues: “We were in for a surprise: Yes, we were able to identify reliably a considerable number of structures in both the SPHERE and the Hubble images. But within those few years, the features had moved away from the star. For the first time, we had observed not only the structure or the spectral features of a stellar debris disks – we were watching the disk change!”

According to a preliminary analysis, which will need to be confirmed by future observations, some of the matter observed might even be on its way out of the disk altogether, with sufficient speed to leave the stellar system behind.

There is, at this moment, no complete explanation for the disk dynamics observed by the combination of SPHERE and Hubble images. AU Mic, a red dwarf star (of type M1 Ve) a little over half the diameter of the Sun, is a rather young star with an age of around 12 million years, compared to our Sun's age of 5 billion years.

As is not uncommon for such young stars, AU Mic is very active, and frequently produces sizable flares: Eruptions involving the star's magnetic field, which catapult stellar plasma at high speed into the star's surroundings. It is possible that the moving features in the dust disk are caused by such stellar activity.

Another, tantalizing possibility is that the changes could be tell-tale signs of the presence of one or more giant planets in the debris disk. In that case, the motion would be due to disturbances caused by one or more planets' gravitational pull as it moves through the disk. So far, no planets around AU Mic have been detected – but this could change as search and imaging techniques improve.

In total, the surprising observations of disk changes around AU Mic provide for a whole programme of additional observations. If the researchers are very lucky, they might even be able to detect proto-planets – smaller bodies busily gathering sufficient mass for planethood – within the disk. More generally, extending observations such as these should allow for detailed comparison with simulations of such objects – and could shed light on processes of planet formation, which might have left tell-tale traces on the disk.

Contact

Dr. Markus Pössel
Press & Public Relations

Max Planck Institute for Astronomy, Heidelberg
Phone: +49 6221 528-261

Email: poessel@mpia.de


Prof. Dr. Thomas Henning
Max Planck Institute for Astronomy, Heidelberg
Phone: +49 6221 528-200

Fax:  +49 6221 528-339

Email: henning@mpia.de


Original publication
Boccaletti et al.
Fast-Moving Structures in the Debris Disk Around AU Microscopii
Nature, 8 October 2015

Dr. Markus Pössel | Max Planck Institute for Astronomy, Heidelberg

More articles from Physics and Astronomy:

nachricht Tangled magnetic fields power cosmic particle accelerators
14.12.2018 | DOE/SLAC National Accelerator Laboratory

nachricht In search of missing worlds, Hubble finds a fast evaporating exoplanet
14.12.2018 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Data use draining your battery? Tiny device to speed up memory while also saving power

The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.

Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...

Im Focus: An energy-efficient way to stay warm: Sew high-tech heating patches to your clothes

Personal patches could reduce energy waste in buildings, Rutgers-led study says

What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...

Im Focus: Lethal combination: Drug cocktail turns off the juice to cancer cells

A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.

The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...

Im Focus: New Foldable Drone Flies through Narrow Holes in Rescue Missions

A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.

Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...

Im Focus: Topological material switched off and on for the first time

Key advance for future topological transistors

Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

New Plastics Economy Investor Forum - Meeting Point for Innovations

10.12.2018 | Event News

EGU 2019 meeting: Media registration now open

06.12.2018 | Event News

 
Latest News

Data use draining your battery? Tiny device to speed up memory while also saving power

14.12.2018 | Power and Electrical Engineering

Tangled magnetic fields power cosmic particle accelerators

14.12.2018 | Physics and Astronomy

In search of missing worlds, Hubble finds a fast evaporating exoplanet

14.12.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>