English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The structure of the Kreutz system of sungrazing comets is shown to be muchmore complex than formerly believed. Marsden's (1989) division into threesubgroups (I, II, IIa) is now greatly expanded, as new evidence is beingoffered on nine populations of fragments -- I, Ia, II, IIa, III, Pre-I, Pe(side branch of I), IIIa, and IV, incorporating carefully screened data setsfrom a collection of gravitational orbits for 1500 SOHO/STEREO dwarf Kreutzcomets. Tight correlations between the nominal perihelion latitude and nominallongitude of the ascending node are the result of ignored effects of anoutgassing-driven acceleration on the orbital motion. The average width of agap between adjacent populations in the corrected nodal longitude is near 9deg; the overall range equals 66 deg. A self-consistent model postulates (i) aninitial breakup, in general proximity of aphelion, of a contact-binary parent(progenitor) into its two lobes and the neck (originally linking the lobes),giving birth to, respectively, Population I (Lobe I; the main residual massC/1843 D1), Population II (Lobe II; C/1882 R1), and Population Ia (the neck);followed by (ii) progressive fragmentation of the lobes (primarily Lobe II),mostly (but not exclusively) far from perihelion, giving successively rise tothe other populations and clusters of naked-eye Kreutz sungrazers and theirdebris. The separation velocities were a few meters per second. Massivefragments of Populations Pre-I, IIIa, and IV are yet to be discovered.Relations among the products of cascading fragmentation are depicted in apedigree chart. The age of the Kreutz system is estimated at two millennia anda mean orbital period of Lobe I and its main residual mass at ~740 yr. Thestatus is reviewed of the possible historical Kreutz comets seen in AD 1106, AD363, and 372 BC.

New Model for the Kreutz Sungrazer System: Contact-Binary Parent and Upgraded Classification of Discrete Fragment Populations