Finite Lifetime Fragment Model 3 for striae formation in the dust tails of comets (FLM 3)

• Published in: Icarus (New York, N.Y. 1962) Vol. 370; p. 114649
• Main Author: Nishioka, Kimihiko
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.12.2021
• Subjects: Comet; Dust; Electromagnetic-force; Striae; Tail; Dust; Comet; Electromagnetic-force; Striae; Tail
• ISSN: 0019-1035; 1090-2643
• DOI: 10.1016/j.icarus.2021.114649

The striations in the Type II tail of the comets are called striae. The origin of the striae has been poorly understood. We present a new dynamical model to explain the structure of the striae observed at comets Hale-Bopp (C/1995O1), West (C/1975V1), and Seki-Lines (C/1962C1). Complex particles of absorbent and refractory particles with a radius of less than 1 μm are ejected from the nucleus of the comet and repeatedly decay to form striae with a lifetime of less than about 100 days at 1 AU. They continue to decay further and eventually disappear from sight. The above material science processes are explained by the following dynamical model. The particles ejected from the nucleus of a comet are assumed to be subjected to three forces: solar gravity, solar radiation pressure, and electromagnetic force. As the particle ejected from the nucleus of a comet decreases in size, the radiation pressure increases, decreases, increases and decreases or increases and decreases, forming a stria. The electromagnetic force is treated as an approximate theory and considered as a perturbation. This model is less of a dynamical approximation than previous theories, explains the structure of the striae, and also allows us to predict their luminosity and elucidate the origin of the striae. •A new dynamical model was proposed to explain the morphology of the striae of comets.•The stria is formed by the continuous decay of particles ejected from the comet.•We consider that particles above 0.005 μm in the process of decay are visible as a stria.•Particles are subjected to gravity, radiation pressure and electromagnetic force.•The electromagnetic force is assumed to act to change the angular momentum of the stria.