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NASA planet hunter discovers a planet the size of Earth at 53 light-years
WASHINGTON: NASA 's spacecraft research spacecraft launched last year discovered a planet the size of the Earth and a planet the size of a size smaller than Neptune in a system. near stars.
The study published Monday in the journal The Astrophysical Journal Letters reported that the Earth-sized planet called HD 21749c takes eight days to revolve around its host star.
The host star of these two planets represents about 80% of the Sun's mass and is located about 53 light-years from Earth.
The Transiting Exoplanet Survey Satellite (TSS), launched on April 18, 2018, is NASA's latest satellite to search for planets outside our solar system.
It will monitor the brightness of more than 200,000 stars over a two-year period, monitoring the temporary dimming caused by planetary transits.
In addition, a tool called Planet Finder Spectrograph (PFS) installed in an observatory in Chile was used to confirm the global nature of the TESS signal and to measure the mass of recently discovered exoplanets.
"Measuring the exact mass and composition of such a small planet will be important for comparing HD 21749c to Earth," said Sharon Wang, astronomer of the Washington Carnegie Institution.
Astronomers are able to measure for the first time the masses, atmospheric compositions and other properties of many smaller exoplanets, thanks to TESS and PFS.
"For very close and very bright stars, we expected to find about twenty planets the size of the Earth," said Johanna Teske, also a researcher at Carnegie.
"This would be our first, and it's an important step for TESS.
It paves the way for smaller planets around even smaller stars, and these planets can potentially be habitable, "Teske said.
Astronomers have also discovered in the astronomical system a planet HD 21749b, about 23 times the mass of the Earth, but less massive than Neptune.
It has a radius of about 2.7 times that of the Earth.
According to the study, the HD 21749b has an orbit that lasts about 36 days. This is the longest period of all TESS discoveries published to date.
Its density indicates that the planet has a substantial atmosphere, but it is not rocky. It can help astronomers understand the composition and evolution of Neptune's warmer planet atmospheres.
According to the researchers, small exoplanets are common in our galaxy, but there is still much to learn about their diversity.
TESS will study more than 90% of the sky and transmit its observations to Earth every 13.5 days. (Xinhua / APP)
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