Core Viewpoint - Astronomers are reigniting the search for a potential unknown planet, referred to as "Planet Y," which may be influencing the orbits of distant celestial bodies in the Kuiper Belt, suggesting the presence of a mysterious force affecting these orbits [3][4]. Group 1: Discovery of Planet Y - A recent study by astrophysicist Amir Siraj from Princeton University proposes that the gravitational influence of "Planet Y" could explain the unusual orbital tilts of approximately 50 cold celestial bodies in the Kuiper Belt, which are tilted about 15 degrees [3][4]. - The study indicates that the observed orbital tilt is significantly beyond the gravitational effects of Neptune, with a confidence level of 96%-98% [4]. Group 2: Characteristics of Planet Y - "Planet Y" is hypothesized to have a mass between that of Earth and Mercury, located approximately 100-200 astronomical units from the Sun, with an orbital tilt of at least 10 degrees [5]. - This hypothetical planet is distinct from the previously theorized "Planet X" or "Ninth Planet," which is suggested to be much larger and farther from the Sun [7]. Group 3: Historical Context - The search for unknown planets in the solar system dates back to the 19th century, with the concept of "Planet X" introduced by Percival Lowell, which was later reignited by the discovery of Eris in 2005 [6]. - The "Ninth Planet" hypothesis, proposed by Mike Brown and colleagues in 2016, suggests a massive planet with a mass 5-10 times that of Earth, orbiting at a distance of about 550 times that of the Earth from the Sun [6]. Group 4: Future Observations - The upcoming Vera C. Rubin Observatory's ten-year "Legacy Survey of Space and Time" project is expected to provide critical data that could confirm the existence of "Planet Y" or the "Ninth Planet" [8]. - This observatory, equipped with the world's largest digital camera, will conduct systematic observations of the southern sky, potentially detecting "Planet Y" within the first few years of its operation [8].

Core Viewpoint - The research led by astrophysicist Amir Siraj from Princeton University suggests the existence of a previously undetected planet, referred to as "Planet Y," which may be influencing the orbits of distant celestial bodies beyond Neptune [1][3]. Group 1: Research Findings - The study published in the Monthly Notices of the Royal Astronomical Society proposes that the gravitational pull of "Planet Y" could be the reason behind the orbital anomalies of approximately 50 cold Kuiper Belt objects, with their orbits tilted by about 15 degrees [3][4]. - The analysis indicates a 96%-98% confidence level in the observed orbital tilt, which exceeds the gravitational influence of Neptune [4][6]. - Simulations suggest that a celestial body with a mass between Mercury and Earth, located 100-200 astronomical units from the Sun, could account for the observed tilt in the Kuiper Belt's orbital plane [4][5]. Group 2: Historical Context - The concept of an unknown planet affecting the orbits of Neptune and Uranus dates back to the 19th century, with the idea of "Planet X" proposed by astronomer Percival Lowell [5]. - The discovery of Eris in 2005 reignited interest in the search for distant planets, leading to the hypothesis of a "Ninth Planet" proposed by Mike Brown and colleagues in 2016 [5][6]. - The current "Planet Y" theory does not negate the existence of the "Ninth Planet" but offers an alternative explanation for the observed orbital distortions in the Kuiper Belt [6]. Group 3: Future Observations - The upcoming Vera C. Rubin Observatory in Chile is expected to play a crucial role in confirming the existence of "Planet Y" or the "Ninth Planet" through its extensive survey of the southern sky over the next decade [8]. - The observatory's capabilities will allow for systematic observations of distant celestial bodies, potentially leading to the direct detection of "Planet Y" within the first few years of its operation [8].

Core Points - A potential dwarf planet named 2017 OF201 has been discovered beyond Neptune, challenging the existence of hypothetical celestial bodies like "Planet Nine" [1][2] - The discovery was made by researchers at Princeton University using data from the Victor M. Blanco Telescope in Chile, with 2017 OF201 having a diameter of approximately 700 kilometers, making it comparable to Pluto [1] - The orbit of 2017 OF201 is significantly distant, currently about 90.5 astronomical units (AU) from Earth, and it has a perihelion of 44.5 AU and an aphelion of 1600 AU [1][2] Group 1 - The orbit of 2017 OF201 does not conform to the patterns observed in other extreme trans-Neptunian objects (TNOs), which some researchers believe could indicate the presence of "Planet Nine" [2][3] - Simulations suggest that if "Planet Nine" exists, 2017 OF201 would be ejected from the solar system over millions of years, indicating that its existence does not support the hypothesis of "Planet Nine" [3] - The upcoming Vera C. Rubin Observatory in Chile is expected to enhance the search for similar celestial bodies, potentially providing more insights into the existence of "Planet Nine" [4]