Core Insights - An international team led by Professor Dong Subo from Peking University's Department of Astronomy has confirmed the planetary identity of a candidate rogue planet, marking a significant achievement in the field of astronomy [1][2] Group 1: Discovery and Methodology - Rogue planets do not orbit stars but drift through interstellar space, making them difficult to detect due to their lack of intrinsic light [1] - The team utilized the gravitational lensing effect, proposed by Einstein, to capture the rogue planet's presence as it passed in front of a distant star, causing a temporary increase in the star's brightness [1] - Approximately 10 candidate rogue planets have been identified using this method previously, but their masses could not be independently and accurately measured until now [1] Group 2: Observational Details - The rogue planet candidate was discovered on May 3, 2024, during a micro-lensing event that lasted about two days [2] - The European Space Agency's Gaia satellite was uniquely positioned to observe this event, covering the peak brightness phase for 16 hours and completing six measurements [1][2] - Such an opportunity for observation has only occurred once in Gaia's over 10 years of operation [1] Group 3: Findings and Implications - The analysis of ground and Gaia observational data led to the conclusion that the mass of the rogue planet candidate is comparable to that of Saturn [2] - This finding confirms that the candidate is indeed a planet, ruling out the possibility of it being a more massive brown dwarf or a star [2]

Core Findings - An international team led by Nanjing University discovered a "nested" four-star system consisting of a pair of red dwarfs and a pair of brown dwarfs, located 82 light-years away, providing a rare sample for solving the age measurement problem of brown dwarfs [1][2] - The two pairs of binary stars in the system are separated by 1656 astronomical units, with an orbital period exceeding 100,000 years [1] - The red dwarfs have a surface temperature of approximately 2900 degrees Celsius and each has a mass of less than one-fifth that of the Sun, while the brown dwarfs have surface temperatures of only 550 degrees Celsius and 420 degrees Celsius [1] Age Measurement Insights - The age of the four-star system is estimated to be between 300 million and 2 billion years, derived from the intensity of hydrogen emission lines in the spectra of the red dwarfs, indirectly solving the age mystery of the two brown dwarfs [2] - The discovery of this four-star system is expected to serve as a benchmark reference for calibrating brown dwarf evolution models, which is significant for the study of "substellar" objects [2]