In the context of the recently proposed contact-binary model (Sekanina 2021), I investigate the circumstances of the first perihelion passage of the Kreutz sungrazers in orbits with barycentric periods near 735 yr, following the initial near-aphelion splitting of the presumed progenitor, Aristotle's comet of 372 BC. Given favorable conditions at this breakup and at episodes of secondary fragmentation in its aftermath, the fragments should have arrived at their first perihelion nearly simultaneously, reminiscent of the anticipated outcome for the two-superfragment model's perihelion return of AD 356 (Sekanina & Chodas 2004). The relevant case of a swarm of Kreutz sungrazers is examined to appraise possible scientific ramifications of the brief remark by Ammianus Marcellinus, a Roman historian, that "in broad daylight comets were seen" in late AD 363, only seven years later. The tested scenario, which does not contradict Ammianus' narrative and is consistent with the contact-binary model, involves a set of ten sungrazers visible in the daytime, all reaching perihelion over a period of 4.6 days. As part of this work, I comment on the role of the rapidly developing, brilliant post-perihelion tail; revise the apparent magnitude typical for the first and last naked-eye sightings; compare the visibility conditions in full daylight, in twilight, and at night; and, for the first time, present circumstantial evidence that favors comet X/1106 C1 as the parent to C/1843 D1 rather than to C/1882 R1 and C/1965 S1.
The Great Comet of 1106, a Chinese Comet of 1138, and Daylight Comets in late 363 As Key Objects in Computer Simulated History of Kreutz Sungrazer System
Kreutz Sungrazers: Summary of Recent Modeling and Orbits of the SOHO Objects
我总结和精简的轨道演化和级联的克鲁兹掠日天体的碎片最近的建模结果。该模型从亚里士多德的彗星开始-其核心被假定为接触双星的祖先-在远日点附近分裂成两个裂片，最后以SOHO矮天体作为分裂过程的最终产物。1843年的大三月彗星（Great March Comet）是星族I的成员，1882年的大九月彗星（Great September Comet）是星族II的成员，被认为是现存质量最大的两颗彗星。我确定，克鲁兹星系目前由9个星群组成，其中之一--与佩雷拉彗星有关--是星群I的一个分支。作为新模型的一部分，克罗伊茨系统的补充是公元363年的日光彗星，由罗马历史学家阿米亚努斯·马塞利努斯记录，以及1041年9月和1138年9月的中国彗星，两者都在何的目录中列出。363年的彗星是第一代碎片，后者--连同1106年的大彗星--是第二代碎片。注意力是针对人口的近日点距离的SOHO掠日者的直方图和这个距离作为一个功能的上升交点的经度的绘图。在未来几十年内，明亮的裸眼克鲁兹掠日者的到来被预测。
Comet C/2011 W3 (Lovejoy): Orbit Determination, Outbursts, Disintegration of Nucleus, Dust-Tail Morphology, and Relationship to New Cluster of Bright Sungrazers
