Ion energetics in the inner coma of comet Halley

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

The ion pile-up region in the comet Halley ionosphere observed on the inbound leg of the Giotto trajectory is accompanied by a decrease of the magnetic field strength. This magnetic field dip is explained by means of a diamagnetic effect of the plasma density increase in the pile-up region. Maximum of the plasma pressure seems to coincide with the maximum of the ion density. We arrived at the c...

Monte Carlo modeling of neutral gas and dust in the coma of Comet 1P/Halley

The neutral gas environment of a comet is largely influenced by dissociation of parent molecules created at the surface of the comet and collisions of all the involved species. We compare the results from a kinetic model of the neutral cometary environment with measurements from the Neutral Mass Spectrometer and the Dust Impact Detection System onboard the Giotto spacecraft taken during the fly...

Early Photometry of Comet p / Halley : Development of the Coma 1

Broadband charge-coupled device photomet ry of Comet p/Halley at heliocentric d is tances R = 5.9 A U (1984 October) and R = 5.1 A U (1985 January) is presented. The mean brightness at R = 5.1 A U is greater than expected from an asteroidal br ightness model fitted to earlier photometry . It is likely that this br ightness increase is due to the release of dus t grains from the nucleus beginnin...

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 nucleus and inner coma of Comet 46 P / Wirtanen ?

We report the detection of the nucleus of comet 46P/Wirtanen from analysis of images taken with the Planetary Camera (WFPC2) of the Hubble Space Telescope (HST) on 28 August 1996. The high spatial resolution (a WFPC2 pixel projects to 50 km at the distance of the comet) allowed us to separate the signal of the nucleus from that of the coma and to determine the Landolt V and R magnitudes of the ...