DISCOVERY OF A NEW RETROGRADE TRANS-NEPTUNIAN OBJECT: HINT OF A COMMON ORBITAL PLANE FOR LOW SEMIMAJOR AXIS, HIGH-INCLINATION TNOs AND CENTAURS

• Published in: Astrophysical journal. Letters Vol. 827; no. 2; p. L24
• Main Authors: Chen (陳英同), Ying-Tung, Lin (林省文), Hsing Wen, Holman, Matthew J., Payne, Matthew J., Fraser, Wesley C., Lacerda, Pedro, Ip (葉永烜), Wing-Huen, Chen (陳文屏), Wen-Ping, Kudritzki, Rolf-Peter, Jedicke, Robert, Wainscoat, Richard J., Tonry, John L., Magnier, Eugene A., Waters, Christopher, Kaiser, Nick, Wang, Shiang-Yu, Lehner, Matthew
• Format: Journal Article
• Language: English
• Published: The American Astronomical Society 20.08.2016
• Subjects: Aircraft detection; Clustering; Disks; Dwarf planets; Kuiper belt: general; Oort Cloud; Origins; Planes; surveys; Trans-Neptunian objects
• ISSN: 2041-8205; 2041-8213
• DOI: 10.3847/2041-8205/827/2/L24

ABSTRACT Although the majority of Centaurs are thought to have originated in the scattered disk, with the high-inclination members coming from the Oort cloud, the origin of the high-inclination component of trans-Neptunian objects (TNOs) remains uncertain. We report the discovery of a retrograde TNO, which we nickname "Niku," detected by the Pan-STARRS 1 Outer Solar System Survey. Our numerical integrations show that the orbital dynamics of Niku are very similar to that of 2008 KV42 (Drac), with a half-life of ∼500 Myr. Comparing similar high-inclination TNOs and Centaurs (q > 10 au, a < 100 au, and i > 60°), we find that these objects exhibit a surprising clustering of ascending node, and occupy a common orbital plane. This orbital configuration has high statistical significance: 3.8- . An unknown mechanism is required to explain the observed clustering. This discovery may provide a pathway to investigating a possible reservoir of high-inclination objects.