Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovering the birth of an asteroid trail

22.02.2013
Unlike comets, asteroids are not characterised by exhibiting a trail, but there are now ten exceptions. Spanish researchers have observed one of these rare asteroids from the Gran Telescopio Canarias (Spain) and have discovered that something happened around the 1st July 2011 causing its trail to appear: maybe internal rupture or collision with another asteroid.

Ten asteroids have been located to date that at least at one moment have displayed a trail like that of comets. They are named main-belt comets (MBC) as they have a typical asteroidal orbit but display a trail at the same time. This means that their dust (and possibly gas) emission activity is like comets.


This is an artistic representation of asteroid P/2012 F5. Credit: SINC

One of these objects, baptised as P/2012 F5 (Gibbs), was discovered in March 2012 from the Mount Lemmon Observatory in Arizona (USA). In May and June of that year, Spanish astrophysicists from the Gran Telescopio Canarias tracked it and have discovered when the trail was born using mathematic calculations.

"Our models indicate that it was caused by an impulsive short-lived event lasting just a few hours around the 1st July, 2011, with an uncertainty of 20 days," as explained to SINC by Fernando Moreno, researcher at the Astrophysics Institute of Andalusia (CSIC). In collaboration with other colleagues from the Astrophysics Institute of the Canary Islands and the University of La Laguna, the data have been published in the 'The Astrophysical Journal Letters'.

The telescope images reveal "a fine and elongated dust structure that coincides exactly with the synchrone of that day," says Moreno. For a given observation date, a synchrone is the position in the sky of the particles emitted from these types of objects with zero speed in an instant of time. In this case the synchrone of the 1st July, 2011 is the best adapted to the fine trail.

The width and varying brightness of the head to the end of the trail allowed for the researchers to deduce the physical properties of the particles and proportions of their different sizes.

As for the maximum size and speed values of the liberated particles, the team has calculated that the asteroid should have a radius of between 100 m and 150 m and the dust mass emitted should be about half a million tonnes.

The researchers juggled two possible theories for the origin of the P/2012 F5 trail: "It could have arisen from collision with another asteroid or rather a rotational rupture." The second mechanism consists of material gradually breaking free after partial fragmentation of the asteroid.

In turn, the rapid spinning of the asteroid, "like an accelerating carousel" causes pieces to break off. The rotation speed of small asteroids can increase over time due to the Yarkovsky effect (YORP effect for short). This can induce acceleration due to the thermal differences of the different surface regions of the asteroid, eventually leading to rupture.

Moreno indicates that, from the brightness distribution of the trail, "we have verified that the dependence of the speed of particle ejection on size is very weak, in accordance with what we already obtained for the other asteroid of this group: 596 Scheila, which probably suffered a collision."

MBC activated asteroids

MBCs are main-belt asteroids situated at a distance of between 2 and 3.2 astronomical units, which is the average distance between the Earth and the Sun. For some reason they become active and emit dust. For now they have not been found to generate gas but this could be due to the fact that they are weak at the very moment of observation.

Since the first discovery of an MBC in 1996, the 133P/Elst-Pizarro, a total of ten have now been found. The presence of a trail in some has lasted for a relatively long period of a few months, like in the cases of 2006 VW139 and P/2010 R2 (La Sagra). The latter was discovered from an observatory of the same name in Granada. Its activity could have been due to an ice sublimation which could have released the gas, although this has not been detected.

In other cases, however, activity developed during a short period of time, like in the case of 596 Scheila. Its dust cloud dissipated very quickly in a matter of hardly three or four weeks following its detection.

There are also examples of MBCs that have shown recurrent activity, like 133P/Elst-Pizarro and 238P, which have displayed a trail on more than one occasion.

In the case of P/2012 F5, it is still unknown what group it belongs to. More data will be available when it can be observed again in good conditions next year in around July or August 2014.

The last documented MBC to date is the so-called P/2012 T1 (PANSTARRS), which Spanish astrophysicist are also analysing. Like what has happened with exoplanets, many more main-belt comets will start appearing in the coming years.

References:

Fernando Moreno, Javier Licandro, Antonio Cabrera-Lavers. "A short-duration event as the cause of dust ejection from Main-Belt Comet P/2012 F5 (Gibbs)". The Astrophysical Journal Letters 761 (1), December 2012. Doi: 10.1088/2041-8205/761/1/L12.

SINC | EurekAlert!
Further information:
http://www.fecyt.es

More articles from Physics and Astronomy:

nachricht Scientists take nanoparticle snapshots
11.02.2016 | DOE/Argonne National Laboratory

nachricht New paths for generation of ultracold molecules
11.02.2016 | Max-Planck-Institut für Quantenoptik

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: Production of an AIDS vaccine in algae

Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.

The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

From intelligent knee braces to anti-theft backpacks

26.01.2016 | Event News

 
Latest News

New method opens crystal clear views of biomolecules

11.02.2016 | Life Sciences

Scientists take nanoparticle snapshots

11.02.2016 | Physics and Astronomy

NASA sees development of Tropical Storm 11P in Southwestern Pacific

11.02.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>