"Carbon" snow from distant planets - BBC

Astronomers first saw in the nascent planetary system in an area where snow is formed. Managed to do it based on the results of observations on the largest project in the history of astrophysics – a network of submillimeter telescope ALMA.

studying planets around other stars, along with the notorious “habitable zone,” the astronomers look for other signs, which play an important role in the formation of the planets and perhaps life. One of these features is the “snow line”, the radius of the protoplanetary disk, on which the light compounds such as carbon dioxide freeze, turning into snow.

Snapshot of the protoplanetary disk TW Hydrae, made observatory ALMA

the first time to see this snowy border in the protoplanetary disk around a young star was an international team of astronomers led by Chunhua Qi of the Harvard-Smithsonian Center for Astrophysics (USA). Just as on Earth water freezes at latitudes where the temperature drops below zero, moving deeper into the star of protoplanetary disks, you can find an area where crystallize water, carbon dioxide (CO ² ), methane (CH ⁴ ) or carbon monoxide (CO).

Star with conditions to stay

Astronomers have found three potentially habitable planets in the star Gliese 667C. ?

Using observations ALMA Observatory in the Chilean Atacama Desert, the scientists were able to see the area of ??the protoplanetary disk around the star TW Hydrae, in which there is “snow” of carbon monoxide. This star age of 10 million years, is located 175 light-years away, she discovered a protoplanetary disk and one formed yupiteropodobnaya planet.

According to scientists, the young star is a model of the early solar system, in which 4.5 billion years ago, the planet we were born.

«ALMA gave us the first real picture of the snow line around a young star, which is amazing, because it tells us about the early period of our own solar system. Now we can see the details of previously inaccessible freezing outside areas other systems resembling our solar system when it was no more than 10 million years “, – said Chunhua.

planets are born from star dust trapped in a nut

Astronomers first saw where and how new planets are born: the process is in special traps dust, where the particles stick together without interfering with each other. ?

Such

snow line in the protoplanetary disks of young stars have never been recorded directly. This is due to the fact that the boundary of the formation of snow is formed not throughout the thickness of proto disk, and its thin central portion. Towards the edges of the disk radiation heats star gases, preventing them from freezing.

determine the radius of the protoplanetary disk, which begins freezing of carbon monoxide, radio astronomers helped a neat trick. Radio telescopes to scan the disk in the wake of the ion N ² H + – diaziniliya, a fragile structure that is destroyed in the presence of gaseous CO. Therefore, the presence of the compound indicates areas where carbon dioxide is in a frozen state.

high sensitivity and spatial resolution of the telescope ALMA possible to trace the area where frozen carbon monoxide, and to outline the strict border snowmaking – 30 astronomical units from the star (1 AU is the average distance from Earth to the Sun).

«Using this technique, we were able to create a photographic negative” snow “of carbon monoxide in the disk around TW Hydrae, – says Karin Oberg, participant observation, the results of which were published in Science. – It gave us a chance to see the snow line exactly where predicted by theory – at the inner edge of the ring diaziniliya ».

Areas in which volatile substances freeze, turning into snow and ice, play an important role in the formation of planets from a protoplanetary disk.

Asteroids inundated white dwarfs

on white dwarfs – crystal clear remnants of stars – can crumble surviving protoplanets and asteroids. Cosmic archeology engaged … ?

snow adhering to dust particles, making them sticky, making it difficult to bounce off each other and contributing to their association.

This buildup can greatly accelerate the process of planets, as well as a line of snow can be more than one, they can provoke the birth of several planets. In our solar system, snow water line corresponds to the orbit of Jupiter, the snow of carbon monoxide – the orbit of Neptune. Outside of this particular zone can be created and exist stably comets and icy dwarf planet. Detection line “CO” snow important in that it involves the formation of methanol, more complex organic molecules necessary for life.