Bright Sungrazing Comets in a Great Historical Controversy and Prospects for Their Appearance in the Near Future

Abstract

Until the second half of the 19th century, two or more brief appearances of bright comets, such as the ones in 1668 and 1702, alike in aspect and motion, seen with a tail near the Sun, were almost universally believed to be periodic returns of a single object. It is likely that the exceptional story of Halley's comet was the compelling precedent for this school of thought. Application to sungrazers was discredited by the observed fragmentation of the nucleus of the giant sungrazer of 1882 shortly after perihelion. Generally, separations and orbital periods of the Kreutz comets are known to be governed in such events by the solar tidal force, while the range in the longitude of the nodal line is linked to the pyramidal architecture caused by nontidal, cascading fragmentation along the entire orbit and described by an updated contact-binary model. Perception of the sungrazer system was changed dramatically by coronagraphic imaging from space, which led to discovery of up to ten populations of dwarf comets. Past fragmentation patterns have been used to tentatively predict the arrivals of two bright Kreutz sungrazers -- a Population II member around 2027 (and before 2040) and a Population I member around 2050.