In the night of the 14th of December the “Großes Hauptteleskop der Oldenburger Sternwarte” (GHOST) of the university observatory of Oldenburg (G01) was able to recover an Near-Earth Asteroid (NEA) that was missed for 17 years. At first, it was believed that the detected object was a new discovered asteroid, but after several observations of 25 observatories worldwide it became clear that the orbit is identical with the object “2005 XW4” or “K05X04W” which could not be observed anymore since the end of 2005 and the predictions of the orbit were too uncertain. The Oldenburg telescope was one of the first telescopes worldwide that observed the object after the ATLAS telescope at Haleakala (T05), Hawaii, initially (re-)found the object about 10 hours prior. With a visual magnitude of about 18 mag it was a relativly bright NEA, thus many observatories were able to make observations.
2005 XW4 was first discovered at Lincol Laboratory ETS in New Mexico on 6th of December 2005. It is an Near-Earth Asteroid (NEA) with a diameter of 160 m (assuming albedo of 15%) and a minimal orbital intersection distance with Earth of 0.06866 AU (10.3 Million km or about 27 moon distances). Eventhough it is currently not considered a risk according to the ESA risk list, since to current measurements it will not hit Earth in the future, it should be observed frequently to improve the predictions. The goal is that the object is not lost again. This is why the Oldenburg telescopes are observing the object as long as it is close and bright enough.
This is now the second time the university observatory was able to help find objects from the “NEO Confirmation Page” of the MinorPlanetCenter. Since launch of the NEO observation system in Oldenburg, both telescopes of the university observatory, GHOST and ORT, made more than 800 follow-up observations of small objects in the solar system. They submit their measurements to Minor Planet Center (MPC), which combines measurements from observatories all around the world and calculates precise orbits of these objects. This ensures that all objects that could be dangerous for Earth are tracked. An original research article was published in October about the system in Oldenburg. It can be read here: https://www.frontiersin.org/articles/10.3389/fspas.2022.895732/full
More Information on the object 2005 XW4: