On the diamagnetic effect associated with the ion pile-up region in the coma of comet Halley

Cometary magnetospheres: a tutorial

The nucleus of an active comet, such as comet Halley near its perihelion, produces large quantities of gas and dust. The resulting cometary atmosphere, or coma, extends more than a million kilometers into space, where it interacts with the solar wind. An ‘‘induced’’ cometary magnetosphere is a consequence of this interaction. Cometary ion pick-up and mass loading of the solar wind starts to tak...

Ion composition and chemistry in the coma of Comet 1P/Halley—A comparison between Giotto's Ion Mass Spectrometer and our ion-chemical network

The Distributed Co in Comet Halley

Examination of the spatial distribution of CO intensity of Comet Halley indicates that a large fraction of CO originates from the refractory organic component in the coma, rather than directly from the volatiles in the nucleus. Based on the fluffy aggregate interstellar dust comet model, we have estimated the upper limits of the total amount of CO provided by coma dust. The implications from th...

Charge-Coupled Device Photometry of Comet P/Halley

Comet P/Halley has been observed during its approach to perihelion at heliocentric distances R = I 1.0 AU and R = 8.2 AU. No extended coma is seen and limits can be placed on the fraction of the total light contributed by coma. The brightness of the comet varies on a short time scale. The variations may be due to transient activity or to rotation of the irregular nucleus. ,. 1984 Academic Pre',...

Evidence for methane and ammonia in the coma of comet P/Halley.

Methane and ammonia abundances in the coma of Halley are derived from Giotto IMS data using an Eulerian model of chemical and physical processes inside the contact surface to simulate Giotto HIS ion mass spectral data for mass-to-charge ratios (m/q) from 15 to 19. The ratio m/q = 19/18 as a function of distance from the nucleus is not reproduced by a model for a pure water coma. It is necessary...