A recent study has revealed that all the seven екзопланет in the stellar system of TRAPPIST-1 have similar densities and Earth-like composition.This is significant because it builds the knowledge-base for a model of understanding of Earth-like екзопланет outside of solar system.
Зірки in the galaxies have stellar systems comprising mainly of their планети and satellites. For example, our home stellar system viz. solar system has nine планети (of varying densities, sizes and compositions) and their satellites. Mercury, Venus, Earth and березня, чотири планети closet to Sun have rocky surfaces hence are referred to as terrestrial planets. On the other hand, Jupiter, Saturn, Uranus, Neptune are made of gases. The планета Earth in the stellar system of Sun is unique in supporting life.
The quest for habitable worlds beyond Earth means search for habitable планети in the stellar systems of other Число зірок:. There could be trillions of planets outside of the solar system. Such планети називаються екзопланет. Does any of the innumerable екзопланет support life? Any such екзопланета can only be terrestrial one with hard rocky surface like Earth. Study of terrestrial екзопланет therefore, is a very interesting area of study. The екзопланета community is an active research community in pursuit of identifying potential life-bearing worlds in the stars outside of the solar system.
Карлик зірка TRAPPIST-1 was discovered in 1999. This ultra-cool star is situated at a distance of 40 light years. In 2016, three екзопланет were reported in the stellar system of this зірка which was revised to seven subsequently in 2017. Three of the exoplanets are thought to be in habitable zone (1) .
The knowledge about these екзопланет in the stellar system of TRAPPIST-1 is growing continuously. The earlier studies had revealed that these planets are roughly the size and mass of the Earth. This meant these планети have rocky surfaces hence Earth-like terrestrial planets. And, these are closely located in орбіти in close proximity to the star. The latest finding reported is that all the planets are of similar densities and made of similar materials.
використання простір and ground-based telescopes, the scientists have done a precise measurement of the transit times (the time taken by the planets to transit the star measured indirectly by dips in the brightness of the star when the planets cross in front of it) which enabled them refine the mass ratios of the planets to the star. Following this, they carried out photodynamical analysis and derived the densities of the star and the planets. This revealed that all the seven екзопланет have similar densities and Earth-like composition possibly due to little less iron content than the Earth (2,3).
Це остання розробка в розумінні щільності та складу планети in the stellar system of TRAPPIST-1 is significant because it builds the knowledge-base for a model of understanding of Earth-like екзопланет outside of solar system.
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джерела:
- NASA 2017. Новини – Телескоп NASA виявив найбільшу партію планет розміром із Землю в зоні проживання навколо однієї зірки. Опубліковано 21 лютого 2017 р. Доступно в Інтернеті за адресою https://exoplanets.nasa.gov/news/1419/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around-single-star/ Доступ 25 січня 2021 року.
- NASA 2021. Новини JPL – ЕКЗОПЛАНЕТИ - 7 планет Rocky TRAPPIST-1 можуть бути зроблені з подібного матеріалу. Опубліковано 22 січня 2021 року. https://www.jpl.nasa.gov/news/the-7-rocky-trappist-1-planets-may-be-made-of-similar-stuff/
- Агол Е., Дорн К. та інші 2021. Уточнення синхронізації та фотометричного аналізу TRAPPIST-1: маси, радіуси, щільності, динаміка та ефемериди. The Planetary Science Journal, том 2, номер 1. Опубліковано 2021 січня 22 року. DOI: https://doi.org/10.3847/PSJ/abd022
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