(NLDO) - The TRAPPIST-1 star system consists of 7 planets that can bring an interesting "time-traveling" look into the past of the world we live in.
TRAPPIST-1 is an ultra-cool dwarf star 38.8 light years away in the constellation Aquarius. It hosts seven planets, each with properties similar to Earth, some of which are even expected to harbor life.
A new study has "traveled back in time" to find out how these seven fascinating planets came to be.
The cool, red star TRAPPIST-1 and its seven orbiting planets - Photo: NASA/Robert Lea
Astronomer Gabriele Pichierri from the California Institute of Technology (Caltech - USA) and colleagues have created a model to explain the special orbital configuration of the TRAPPIST-1 system.
Previously, the neighboring planetary pairs in this system were found to have period ratios of 8:5, 5:3, 3:2, 3:2, 4:3, and 3:2, respectively. This causes them to form a rhythmic dance when "dancing" around their parent star, called orbital resonance. However, there is a slight "off-beat": TRAPPIST-1 b and TRAPPIST-1 c are 8:5; while TRAPPIST-1 c and TRAPPIST-1 d are 5:3. This inadvertently revealed a complex planetary migration history within the system.
According to the authors, most planetary systems are thought to have started out in orbital resonance states, but then encountered significant instability during their lifetimes and became out of sync.
The model shows that the system's four original planets, located close to their parent star, evolved individually in a regular 3:2 resonance sequence.
Only as the inner boundary of the protoplanetary disk—which exists around stars when they are young and serves as the disk of material from which planets coalesce—expanded outward did their orbits relax and form the configuration we observe today.
The fourth planet, initially located at the inner boundary of the disk, migrated farther out, then was pushed inward again as the three outer planets formed during the second stage of the system's formation.
This new discovery helps us better understand a process that took place in the early solar system, including Jupiter - the first planet to form - moving and jostling the remaining gestating planets.
In addition, the above results also show that the Solar System in its "primordial" days was a much harsher world, with large collisions pushing the eight planets in the system into the chaotic dance they have today.
The new study was just published in the scientific journal Nature Astronomy.
Source: https://nld.com.vn/phat-hien-bat-ngo-ve-su-ra-doi-cua-7-hanh-tinh-gan-giong-trai-dat-196240823112713953.htm
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