Astronomers have discovered an object that does not fit into the modern theory of planetary formation. We are talking about a circumstellar disk that still contains a huge mass of gas, although the latter had to dissipate.
the Discovery is described in two research articles, published in journals Astrophysical Journal and Astrophysical Journal Letters.
According to modern theories of star and planet arise from the same cloud of material called a protoplanetary disk. Luminary when it is born early. Disk remaining after the formation of stars contains gas and dust. Gradually, the gas enters into the composition of planets and icy bodies, and the rest is dissipated in the space under the light pressure of the local sun. Remains a cloud of dust and small boulders, almost devoid of gas. This so-called residual disk.
These theories are backed up by a huge number of observations. Astronomers know a lot of protoplanetary disks in various stages of development, newborn exoplanets and a lot of residual disks. However, this time the scientists discovered something in space that do not fit into existing models.
Composite image of a disk drive according to ALMA. Red shows the emission of dust and green carbon monoxide gas blue – atomic carbon.Illustration of ALMA (ESO/NAOJ/NRAO), Higuchi et al.
we are Talking about around the star 49 China, located about 190 light-years from Earth. This young luminary: he is only 40 million years (for comparison: the Sun is about five billion). But, according to accepted theories, the gas of the protoplanetary disk during this time had already scattered (note that the planets of this star have not yet been discovered). However, recent observations have shown that it is not.
“with more than 100 hours of observations at the ASTE telescope, we have detected in the residual disk around 49 Ceti from the gas to atomic carbon,” says the first author of both articles Nd XIguchi (Aya Higuchi) from the National astronomical Observatory of Japan.
Intrigued, the researchers used a more powerful telescope ALMA. And here they expect a real surprise. Carbon gas around the sun were 10 times more than it was possible to conclude, based on data from ASTE.
Astronomers have distinguished even the emission of carbon-13. As the authors note, earlier the glow of this rare isotope at a frequency of 492 GHz have never been found not only in the residual discs, but also anywhere else in the interstellar medium.
“the Number of 13C [in nature] is only 1% of [amount] 12C, therefore, the detection of 13C in the residual CD was a complete surprise – says squire Higuchi. Is clear evidence that 49 the whale is surrounded by a surprisingly large amount of gas.”
the Emission of the disk around 49 China, according to ALMA, separated by components. Translation Of “News.Science.”Illustration of ALMA (ESO/NAOJ/NRAO), Higuchi et al.
the Researchers also observed the emission of dust and carbon monoxide (co). Explain that this is the most common molecule in the vicinity of young stars after hydrogen (H2). After analyzing the data, the researchers came to the conclusion that the extent of the atomic cloud of carbon comparable to the disk of dust and carbon monoxide.
the Amount of gas remaining in the disk around 49 China is comparable to that in protoplanetary disks, which are still actively forming planets. Scientists are not yet ready to explain this fact.
If it is the initial substance of the protoplanetary disk, it is unclear why it is still not dissipated. The authors also suggested that the gas could be formed during massive collisions of icy bodies such as comets. However, current theory does not explain how it could have happened like the battle on the ice. In short, the universe is again put forth a riddle astronomers.
By the way, earlier the authors “Conduct.Science” (nauka.vesti.ru) wrote about the other results, casts doubt on the standard models of the formation of worlds. Among them a large-scale study of the chemical composition of atmospheres of exoplanets and the discovery of a giant planet around the red dwarf.