On the brightness variations of comet Halley at large heliocentric distances

Abstract

Sporadic variations of its intrinsic brightness of up to 500%, with time scales as short as a few hours, has been exhibited by Halley's comet at large heliocentric distances . It is shown that many of these brightness enhancements are closely correlated to the encounter of high-speed solar wind streams by the comet. It is proposed that during such periods the night side of the comet gets charged to numerically large negative electrostatic potentials, with consequent electrostatic levitation and blow-off of fine charged dust grains lying on it. This gives rise to the observed brightness variations.

The role of solar-wind velocity-waves in comet outburst activity

“…This is supported by the recent work of Flammer et al (1986). This is supported by the recent work of Flammer et al (1986).…”

New Activity of Chiron: Results from 5 Years of Photometric Monitoring

“…(1981) to explain dust blow-off from comets at large heliocentric distances. The basis of this mechanism is the electrostatic charging of the bare cometary nucleus by the solar wind and solar UV radiation at large heliocentric distances, when there is no protective cometary atmosphere (Flammer et al 1985).…”

Cometary outbursts - search of probable mechanisms - case of 29P/Schwassmann-Wachmann 1

“…However, for simplicity one can adopt his result to other comets. This mechanism can only cause the variation of cometary brightness as Flammer et al (1986) showed. The second mechanism -electrostatic destruction of the cometary water ice grains and dust particles in the head of a comet will be considered.…”