![]() 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. For some reason they become active and emit dust. 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. ![]() 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.” It could have arisen from collision with another asteroid or rather a rotational rupture. Video Credit: SINC In May and June of that year, Spanish astrophysicists from the Gran Telescopio Canarias tracked it and discovered when the trail was born. P/2012 F5 (Gibbs) was discovered in March 2012 from the Mount Lemmon Observatory in Arizona (USA). This can induce acceleration due to the thermal differences of the different surface regions of the asteroid, eventually leading to rupture. The rotation speed of small asteroids can increase over time due to the Yarkovsky effect (YORP effect for short). In turn, the rapid spinning of the asteroid, “like an accelerating carousel” causes pieces to break off. 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. 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.Īs 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. In this case the synchrone of the 1st July, 2011 is the best adapted to the fine trail. 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. The telescope images reveal “a fine and elongated dust structure that coincides exactly with the synchrone of that day,” says Moreno. 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‘. “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 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. One of these objects, baptised as P/2012 F5 (Gibbs), was discovered in March 2012 from the Mount Lemmon Observatory in Arizona (USA). This means that their dust (and possibly gas) emission activity is like comets. They are named main-belt comets (MBC) as they have a typical asteroidal orbit but display a trail at the same time. Ten asteroids have been located to date that at least at one moment have displayed a trail like that of comets. This is an artistic representation of asteroid P P/2012 F5 (Gibbs). Image Credit: SINC 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. Unlike comets, asteroids are not characterized by exhibiting a trail, but there are now ten exceptions.
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