A second look at KBO 55636

摘要

Kuiper belt objects (KBOs), small icy bodies orbiting in the Solar System beyond Neptune, are difficult observational targets. Occasionally one is spotted causing a stellar occultation, when data relevant to its structure can be obtained and a few properties deduced. But the stellar occultation of 9 October 2009, involving KBO 55636, a member of the water-ice rich Haumea collisional family, was a landmark event taking the observational astronomy of KBOs to a new level. Following several years of tracking of bright KBOs, it was possible to predict an imminent occultation, and to train a number of telescopes in its direction. Despite the vagaries of weather and other observational hazards, more than one (in fact two) separate telescopes were able to make the observation.