Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dusting for Clues: Gemini Discovers Evidence for Recent Planet-Forming Collisions around Nearby Star

13.01.2005


Astronomers using the Gemini South 8-meter telescope in Chile have observed new details in the dusty disk surrounding the nearby star Beta Pictoris which show that a large collision between planetary-sized bodies may have occurred there as recently as the past few decades.



The mid-infrared observations provide the best evidence yet for the occurrence of energetic encounters between planetesimals (small bodies formed of rock or ice) during the process of planetary formation. Amazingly, the observations even allow speculation as to when the event might have happened.

"It is as if we were looking back about 5 billion years and watching our own solar system as it was forming into what we see today," said Dr. Charlie Telesco of the University of Florida who led the team. "Our research is a bit like a detective dusting for fingerprints to figure out a crime scene, only in this case we use the dust as a tracer to show what has happened within the cloud. The properties of the dust show not only that this was a huge collision, but that it probably happened recently in both astronomical and even on human timescales."


The team’s data revealed a significantly higher concentration of small dust grains in one region of the debris disk that gave the Beta Pictoris a lopsided appearance in previous observations. Dr Mark Wyatt, of the UK Astronomy Technology Centre in Edinburgh, has been modelling the structure of Beta Pictoris’ dust disk, to understand the observations. He explains: "When a collision occurs, dust that is as fine as that we are seeing is rapidly blown away from the star, like ash from the charred remains of a fire. The fact that we can still see so much fine dust in this region means that it must have been produced very recently."

Disks of material surrounding stars such as Beta Pictoris are thought to contain objects of all sizes, from small dust grains similar to household dust to large planetesimals, or developing planets. As all of these objects orbit around the star, just like the Earth circles the Sun, they occasionally collide. The largest of these catastrophic encounters leave behind tell-tail debris clouds of fine dust observable at infrared wavelengths. By collecting high-resolution images from across a broad swath of the thermal infrared part of the spectrum, the research team from the U.S., UK and Chile analyzed images of a cloud in the larger Beta Pictoris disk which has properties expected in a post-collision aftermath.

A collision similar to that proposed here may well have created our own Moon several billion years ago when a Mars-sized body collided with what would eventually become the Earth. While the Moon itself formed out of large rocks and debris created by the collision, the small dust particles were blown away by radiation pressure from the young Sun. In the Beta Pictoris system radiation from the central star blows at about 30 times the intensity of the Sun, clearing out small grains even more quickly.

Because the Beta Pictoris disk appears to us edge-on, the observed asymmetry is visible as a bright “clump” in the cigar-shaped cloud of material revolving around the central star. The Gemini images also reveal new structures in the disk that might show where planets are forming in the system. The team is still studying these features, and follow-up observations are planned using Gemini South’s newly silver-coated 8-meter mirror. This silver coating (now on both Gemini instruments) makes the twin telescopes the most powerful facilities on Earth for this type of infrared research.

Beta Pictoris was one of the first "circumstellar" disks discovered by astronomers. It was initially detected in IRAS (Infrared Astronomy Satellite) data in 1983 by Fred Gillett (formerly Gemini’s Lead Scientist) and then imaged by Bradley Smith and Richard Terrile. Its lopsided nature was apparent even then, but until recently, observations yielded insufficient data at high-enough resolutions to allow a complete inventory of the dust grain size and distribution in the cloud. These recent Gemini results are a first step toward accomplishing that goal.

The Gemini data were obtained using the Gemini Thermal-Region Camera Spectrograph (T-ReCS) on the Gemini South Telescope on Cerro Pachón in Chile.

The international team published their findings and conclusions in the January 13 issue of the journal Nature and at the 205th meeting of the American Astronomical Society in San Diego California.

Julia Maddock | alfa
Further information:
http://www.pparc.ac.uk/Nw/beta_pict.asp

More articles from Physics and Astronomy:

nachricht Gamma rays will reach beyond the limits of light
23.10.2017 | Chalmers University of Technology

nachricht Creation of coherent states in molecules by incoherent electrons
23.10.2017 | Tata Institute of Fundamental Research

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>