Detection of a New "chemical" Boundary at Comet Halley

Polarimetric studies of comet Halley

In the present work, the non-spherical grain characteristics of comet Halley are analysed using the T-matrix method at λ= 0.365,0.485 and 0.684μm respectively. In order to analyse the polarisation data of comet Halley, the dust size distribution function derived by Das et al. (2004) for comet Halley is used in the present work. The size range of the grains is taken to be 0.01μm≤ s ≤ 3μm. Using ...

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

Charge exchange avalanche at the cometopause

A sharp (<104 km thick) transition from a solar wind proton dominated flow to a plasma population primarily consisting of relatively cold cometary heavy ions has been observed at a cometocentric distance of about 1.6x105 km by the VEGA and GIOTTO missions. This boundary (the cometopause) was thought to be related to charge transfer processes, but its location and thickness are inconsistent with...

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',...

CORRECTED CHEMICAL SIGNATURES IN STARDUST GLASS REVEAL WILD 2 PARTICLES THAT RESEMBLE MATRIX GRAINS OF AGGREGATE IDPs

Introduction: The Stardust mission obtained the first dust samples in the coma of an active comet for laboratory analyses. Earlier chemical data on dust from an active comet came from the GIOTTO and VEGA missions to comet Halley [1]. For decades aggregate interplanetary dust particles (IDPs) were available from parent bodies other than those of meteorites [2], i.e. comets or comet-like bodies. ...