character, subsequent improvements in observational capabilities have now shown
Phaethon to be one of a class of objects now generally referred to “active asteroids”.
A comet-like tail was discovered in two apparitions by Jewitt et al. (2013) (cf. Hsieh
and Jewitt 2005). It is now the target of a space mission (JAXA’s DESTINY+) to
study its exact nature.
Fig. 4.60 Monte Carlo model calculation of the dynamics of slow moving particles emitted by
comets. Snapshot of particle positions seen after 1.6 orbits of the comet about the Sun (0 ¼ aphelion).
Emission is from a 30
cone about the sub-solar point. Left: Model for a high beta value. Right:
Model for a lower beta value. first row: Particle positions seen from perpendicular to the orbit plane.
Middle row: Particle positions seen from in the orbital plane of the comet. Bottom row: How the
structure in the middle row would appear using a weighting of the production proportional to 1/r h
2
.
A non-linear colour table has been used to emphasize low column densities
4.11 Slow (Large) Moving Particles in the Coma
373
Phaethon to be one of a class of objects now generally referred to “active asteroids”.
A comet-like tail was discovered in two apparitions by Jewitt et al. (2013) (cf. Hsieh
and Jewitt 2005). It is now the target of a space mission (JAXA’s DESTINY+) to
study its exact nature.
Fig. 4.60 Monte Carlo model calculation of the dynamics of slow moving particles emitted by
comets. Snapshot of particle positions seen after 1.6 orbits of the comet about the Sun (0 ¼ aphelion).
Emission is from a 30
cone about the sub-solar point. Left: Model for a high beta value. Right:
Model for a lower beta value. first row: Particle positions seen from perpendicular to the orbit plane.
Middle row: Particle positions seen from in the orbital plane of the comet. Bottom row: How the
structure in the middle row would appear using a weighting of the production proportional to 1/r h
2
.
A non-linear colour table has been used to emphasize low column densities
4.11 Slow (Large) Moving Particles in the Coma
373