天文学者が赤色矮星の周囲で、2つの巨大ガス惑星の外側を岩石惑星が公転するという、惑星形成の標準的なモデルを覆すような惑星系を発見しました。LHS 1903で見つかったこの発見は、惑星が一度に形成されるのではなく、順番に形成される可能性を示唆しています。
ウォーリック大学のトーマス・ウィルソン氏率いる研究チームは、欧州宇宙機関（ESA）の宇宙望遠鏡「Cheops」を含む複数の望遠鏡のデータを用いて、この4つの惑星からなる惑星系を特定しました。これらの惑星は、内側から岩石、ガス、ガス、そして岩石という予想外の順序で並んでいます。一番外側の惑星は、他の惑星が形成された後に、ガスが枯渇した環境で形成されたと見られています。
Astronomers have identified a rare planetary system 190 light-years from Earth featuring a hot Jupiter sharing its orbit with a mini-Neptune closer to the star. This configuration was once considered nearly impossible. New observations from the James Webb Space Telescope provide fresh insights into how the planets formed.
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Astronomers have discovered that aging stars expanding into red giants are engulfing close-orbiting giant planets. A study of nearly half a million stars shows fewer such planets around more evolved red giants, suggesting many have been destroyed. The findings come from data collected by NASA's Transiting Exoplanet Survey Satellite.
A team of astronomers in Japan has discovered evidence of a faint atmosphere surrounding the small trans-Neptunian object 2002 XV93. Previously, only Pluto was known to retain an atmosphere among bodies beyond Neptune due to its stronger gravity. The finding, made via a rare stellar occultation on January 10, 2024 and published in Nature Astronomy, indicates a short-lived atmosphere requiring continuous replenishment.
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Researchers at Michigan State University have developed a computer simulation showing that gravitational collapse can naturally produce double-lobed, snowman-like structures in the outer solar system. These contact binaries make up about 10 percent of planetesimals in the Kuiper Belt beyond Neptune. The findings, published in the Monthly Notices of the Royal Astronomical Society, explain a long-standing puzzle in astronomy.