Iron clouds over hr 8799c

Iron clouds over HR 8799C

The solar system around HR 8799 in a fresh stage of its creation, as an artist introduces

The list of well-known exoplanets now includes a few thousand copies – Now astronomers succeeded for a look at the atmosphere of a gas giant, which is not belonging to our own solar system

The sunrise on HR 8799C could, if the most intergalactic tourism has become the rule, is based on the most familiarities of the Cosmic Province, which is located in the travelers, in which our solar system is located. After all, the journey is not too far: 130 light-years is the mother star HR 8799 away from Earth. The planet, one of four gas giants that circle his sun is like his siblings themselves compared to our Jupiter a giant.

What makes the sunrise so special there were allowed to be the clouds of iron and silicate particles. In the weak light of the local sun, which is 30 to 40 times further than our central star from the earth (and thus in pluto removal), the cloudscape was allowed to work particularly threatening.

The tourist should only be careful not to store his room suit, because the atmosphere also contains a coarse content of poisonous carbon monoxide. That it is also between 600 and 900 degrees Celsius Heib, the visitor interest could also narrate. Since Start the surface gravity, which is about ten times as strong as on the earth, hardly.

For compensation, the Exoplanet HR 8799C may be safe in the presence of at least the interest of astronomers and cosmologists. Although they already have almost 1.000 planets identified outside the solar system, but the vast majority of direct observation are not yet accessible. HR 8799C has the advantage that he is particularly rough on the one hand – and how his siblings in a relatively coarse distance are still relatively young centralized centrifuge at 30 million years.

The researchers from the Keck Observatory on Hawaii, who have discovered him in 2008, now betrayed in Science, as they could gain an insight into his atmosphere – and what for his genesis means.

The recordings underlying the apprentices have made astronomers already two years ago. A sophisticated extraction process has now allowed you to determine the spectrum of the planet in more detail. Among other things, an unexpected high proportion of CO fell on. Also very clear were the for water vapor typical spectral lines. However, the researchers found less H2O than they expected for such a young planet of his coarse. This is interesting because it betrayed something about the creation of the whole system.

Two models for planetary education

For planetary construction, two different models compete: Number 1 ames that gravitational instabilities are trapped in a dust disk. The effect: core and atmosphere of the planet are created together. Theory number 2, on the other hand, prescribes the process in reverses, from the small to the rough – small material colors form by clenching coarse, these unite into ever growing chunks, which someday reach the rough of a planetary core. Only then does the newborn collect his atmosphere from the remaining gas of the dust disk.

One of the discoverer photos of the system by HR 8799. planet "C" Now reveal details about the composition of his atmosphere

The smaller water content in the atmosphere of HR 8799C now plays a role: was here model 1, the measurement data does not fit anymore. The missing water was therefore inserted in its core, which formed, among other things, from ice crystals of the protoplanetary disk. Only when this core had about the 10x mass of the earth, he began to build the atmosphere over his gravity that can watch the astronomers today.

The planet should therefore have arisen about the core accretion, ie model 2,. The researchers therefore find that remarkable, because the whole system HR 8799 reminds of a young variant of our solar system and therefore suits the conclusion. It probably also has an asteroid belt and an oorsche cloud beyond the planetary railways – and further inside maybe a few earthly planets.

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