A recent study has revealed that all the seven exoplanets 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 exoplanets outside of solar system.
ನಕ್ಷತ್ರಗಳು in the galaxies have stellar systems comprising mainly of their ಗ್ರಹಗಳು and satellites. For example, our home stellar system viz. solar system has nine ಗ್ರಹಗಳು (of varying densities, sizes and compositions) and their satellites. Mercury, Venus, Earth and ಮಾರ್ಚ್, the four ಗ್ರಹಗಳು 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 ಗ್ರಹದ Earth in the stellar system of Sun is unique in supporting life.
The quest for habitable worlds beyond Earth means search for habitable ಗ್ರಹಗಳು in the stellar systems of other ನಕ್ಷತ್ರಗಳು. There could be trillions of planets outside of the solar system. Such ಗ್ರಹಗಳು ಕರೆಯಲಾಗುತ್ತದೆ exoplanets. Does any of the innumerable exoplanets support life? Any such exoplanet can only be terrestrial one with hard rocky surface like Earth. Study of terrestrial exoplanets therefore, is a very interesting area of study. The exoplanet community is an active research community in pursuit of identifying potential life-bearing worlds in the stars outside of the solar system.
The dwarf ಸ್ಟಾರ್ TRAPPIST-1 was discovered in 1999. This ultra-cool star is situated at a distance of 40 light years. In 2016, three exoplanets were reported in the stellar system of this ಸ್ಟಾರ್ which was revised to seven subsequently in 2017. Three of the exoplanets are thought to be in habitable zone (1) .
The knowledge about these exoplanets 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 ಗ್ರಹಗಳು have rocky surfaces hence Earth-like terrestrial planets. And, these are closely located in ಕಕ್ಷೆಗಳು in close proximity to the star. The latest finding reported is that all the planets are of similar densities and made of similar materials.
ಬಳಸಿ ಬಾಹ್ಯಾಕಾಶ 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 exoplanets have similar densities and Earth-like composition possibly due to little less iron content than the Earth (2,3).
ಸಾಂದ್ರತೆ ಮತ್ತು ಸಂಯೋಜನೆಯ ತಿಳುವಳಿಕೆಯಲ್ಲಿ ಈ ಇತ್ತೀಚಿನ ಬೆಳವಣಿಗೆ ಗ್ರಹಗಳು in the stellar system of TRAPPIST-1 is significant because it builds the knowledge-base for a model of understanding of Earth-like exoplanets outside of solar system.
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ಮೂಲಗಳು:
- NASA 2017. ಸುದ್ದಿ - NASA ದೂರದರ್ಶಕವು ಒಂದೇ ನಕ್ಷತ್ರದ ಸುತ್ತಲೂ ಭೂಮಿಯ ಗಾತ್ರದ, ವಾಸಯೋಗ್ಯ ವಲಯದ ಗ್ರಹಗಳ ದೊಡ್ಡ ಬ್ಯಾಚ್ ಅನ್ನು ಬಹಿರಂಗಪಡಿಸುತ್ತದೆ. 21 ಫೆಬ್ರವರಿ 2017 ರಂದು ಪೋಸ್ಟ್ ಮಾಡಲಾಗಿದೆ. ಆನ್‌ಲೈನ್‌ನಲ್ಲಿ ಇಲ್ಲಿ ಲಭ್ಯವಿದೆ https://exoplanets.nasa.gov/news/1419/nasa-telescope-reveals-largest-batch-of-earth-size-habitable-zone-planets-around-single-star/ 25 ಜನವರಿ 2021 ರಂದು ಪ್ರವೇಶಿಸಲಾಗಿದೆ.
- NASA 2021. JPL ನ್ಯೂಸ್ - EXOPLANETS - 7 ರಾಕಿ ಟ್ರ್ಯಾಪಿಸ್ಟ್-1 ಗ್ರಹಗಳು ಇದೇ ರೀತಿಯ ವಸ್ತುಗಳಿಂದ ಮಾಡಲ್ಪಟ್ಟಿರಬಹುದು. ಜನವರಿ 22, 2021 ರಂದು ಪೋಸ್ಟ್ ಮಾಡಲಾಗಿದೆ. https://www.jpl.nasa.gov/news/the-7-rocky-trappist-1-planets-may-be-made-of-similar-stuff/
- ಅಗೋಲ್ ಇ., ಡಾರ್ನ್ ಸಿ., ಮತ್ತು ಇತರರು 2021. ಟ್ರಾನ್ಸಿಟ್-ಟೈಮಿಂಗ್ ಮತ್ತು ಫೋಟೊಮೆಟ್ರಿಕ್ ಅನಾಲಿಸಿಸ್ ಆಫ್ ಟ್ರ್ಯಾಪಿಸ್ಟ್-1: ಮಾಸಸ್, ರೇಡಿ, ಡೆನ್ಸಿಟೀಸ್, ಡೈನಾಮಿಕ್ಸ್ ಮತ್ತು ಎಫೆಮೆರೈಡ್ಸ್. ಪ್ಲಾನೆಟರಿ ಸೈನ್ಸ್ ಜರ್ನಲ್, ಸಂಪುಟ 2, ಸಂಖ್ಯೆ 1. ಪ್ರಕಟಿತ 2021 ಜನವರಿ 22. DOI: https://doi.org/10.3847/PSJ/abd022
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