Sungrazers frequently arrive in pairs separated by a few hours. These pairs are too frequent to occur by chance, and cannot be due to break-ups on the previous orbit, because the fragments would have separated by a much greater distance. Instead, it is thought that the pairs result from fragmentations far away from the perihelion. Many comets have been observed to fragment far from perihelion, and it seems that in the case of the Kreutz sungrazers, an initial fragmentation near perihelion can be followed by an ongoing 'cascade' of break-ups throughout the rest of the orbit. The number of Subgroup I Kreutz comets discovered is about four times the number of Subgroup II members. This suggests that the 'grandparent' comet split into parent comets of unequal size. Future Dynamically, the Kreutz sungrazers might continue to be recognised as a distinct family for many thousands of years yet. Eventually, their orbits will be dispersed by gravitational perturbations, although depending on the rate of fragmentation of the constituent parts, the group might be completely destroyed before it is gravitationally dispersed. The continuing discovery of large numbers of the smaller members of the family by SOHO will undoubtedly lead to a greater understanding of how comets break up to form families. It is not possible to estimate the chances of another very bright Kreutz comet arriving in the near future, but given that at least 10 have reached naked-eye visibility over the last 200 years, another great comet from the Kreutz family seems almost certain to arrive at some point. Comet White–Ortiz–Bolelli in 1970 reached an apparent magnitude of 1. In December 2011, Kreutz sungrazer C/2011 W3 (Lovejoy) survived its perihelion passage and had an apparent magnitude of −3. See also List of Kreutz Sungrazers Lists of comets References Further reading Marsden B. G. (1989), The Sungrazing Comets Revisited, Asteroids, comets, meteors III, Proceedings of meeting (AMC 89), Uppsala: Universitet, 1990, eds C. I. Lagerkvist, H. Rickman, B. A. Lindblad., p. 393 External links Sungrazer project website SEDS Kreutz group page Cometography sungrazers page NASA press release about two Sungrazers seen by SOHO Complete list of SOHO comets Real time SOHO data it:Cometa radente#Le comete radenti di Kreutz