Astronomers have concluded that planets begin to form earlier than assumed by current theory. Observations have shown that young gas and dust disks around protostars have several times more available “building material” compared to more Mature discs that well explains the appearance known to us planetary systems. Article accepted for publication in Astronomy & Astrophysics, available on the website arXiv.org.
For a long time it was believed that the planets are born from disks of gas and dust aged from one to three million years. However, current research suggests that substance in them is not enough to form even a single gas giant like Jupiter, not to mention the larger celestial bodies or the whole system of planets. Moreover, in the discs around young stellar objects of class II (a classic representative — the stars of T Tauri type) find evidence of active formation of planets, so astronomers assume that these processes can be started much earlier.
To test this hypothesis, Lukasz Tihonet (Łukasz Tychoniec) of Leiden University, together with colleagues using the interferometer ALMA and the VLA have studied molecular cloud Perseus — giant region of active star formation, located a thousand light-years from Earth. In particular, astronomers were interested in the gas and dust disks around young stellar objects of class 0 and I, whose age presumably ranging from 100 to 500 thousand years.
It turned out that the median mass of dust in disks of class 0 and I is 158 and 52 of the land masses, respectively, 10 and 3 times more mass of dust in disks of class II. This should be enough material in order to form a known planetary system with a certain performance clumping “pebbles” and planetesimals (15 percent for class 0 and 30% for class I).
Scientists obtained results indicate that the planets should begin to emerge very early. If you imagine that the Sun is 45 human years old (not 4.5 billion as in reality), the protostars with disks of gas and dust in the Perseus cloud is only two days. Previously it was thought that on the same analogy, the planets begin to form on the third or seventh day, so now astronomers apparently have to clarify current models of planetary formation.
Despite the fact that today there are several thousands of exoplanets, many of the processes related to their origin still remain a mystery. Recently, researchers have discovered a system in which a planet with a mass about half of Jupiter is drawn into close orbit around a star that is eight times lighter than the Sun that hardly explains modern theories.