In the 30 years since planets orbiting were first discovered,
The planets in our solar system rotatearound the Sun along stable and almost circular trajectories, which suggests that the orbits have not undergone significant changes since the formation of the planets. But many planetary systems orbiting other stars suffer from a very chaotic past.
What is the essence of the discovery?
The relatively calm history of our Solarsystem favored the prosperity of life on Earth. In the search for alien worlds on which life can exist, scientists say, we can narrow the range of targets if we have a way to identify systems with a similarly tranquil past.
An international team of astronomers took on this.question in a study published in the journal Nature Astronomy. It found that between 20% and 35% of Sun-like stars feed on their planets, with the most likely figure being 27%.
What is the research principle?
This suggests that at least a quarterplanetary systems orbiting stars similar to the Sun have had very chaotic and dynamic pasts. Astronomers have observed several exoplanet systems in which large or medium-sized planets have moved significantly. The gravity of these shifting planets could also disrupt the trajectories of other planets or even push them into unstable orbits.
In most of these highly dynamic systems alsoit is likely that some of the planets fell onto their star. But even with the most precise astronomical instruments, it would be very difficult to find out by directly studying exoplanetary systems. Instead, scientists analyzed the chemical composition of stars in binary systems.
Binary systems are composed of two stars,revolving around each other. Both stars tend to form at the same time from the same gas, so they are expected to contain the same set of elements.
However, if one of the two stars fallsplanet, it dissolves into the outer layer of the star. This can change the chemical composition of the star, resulting in more elements, such as iron, from which rocky planets are formed when analyzed.
And what is the use of this?
These results represent a breakthrough instellar astrophysics and exoplanet research. Scientists have not only discovered that devoured planets can change the chemical composition of Sun-like stars, but also that a significant portion of planetary systems have experienced very dynamic pasts, unlike our solar system.
Thus, the study opens up the possibilityusing chemical analysis to identify stars that are more likely to be analogues of our quiet solar system. There are millions of relatively nearby stars similar to the Sun. Without this new method of identifying the most promising targets, the search for Earth 2.0 will be like searching for a needle in a haystack.
Source: livescience
Illustrations: NASA/Tim Pyle, ALMA (ESO/NAOJ/NRAO)
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