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To find out more about the group's in-situ cometary work, visit the Giotto Page.
Prior to the cometary flyby missions of the mid-1980's, virtually all work carried out on cometary physics was based on ground-based observations of these celestial visitors. Although our understanding of the phenomena that occur in the cometary environment has undergone a revolution since the cometary flyby missions, there is still a vast amount to learn, including the information that we can gather from further ground-based observations.
In the Space Plasma Physics Group here at MSSL, the field of cometary
science which we are most interested in is that of comet-solar wind
interactions. Cometary plasma can be
imaged by selecting wavelengths at which the ions fluoresce following excitation
by solar UV radiation. The images obtained using this method include sunlight
scattered by dust in the comet's coma. Therefore, to remove this component
of the images, we also obtain images in a wavelength region where there is no
ion emission. By subtracting the latter from the former, we obtain images of the
cometary plasma alone.
These images were all taken with the Radcliffe Telescope at the University of London Observatory with the help of Steve Fossey.
This first image is a true-colour image taken on the morning of March 27th - the comet was at the time exactly side-on to the Earth. The view is around 35000km across. The blue features on either side of the tail are complex structures in the C2 emission.
This image is a close-up of the above - showing the inner regions of the dust fan.
This image is of H2O+ emission alone - an image taken through a H2O+ filter minus an image taken through a dust filter. The nucleus has rotated between the times that the two images were taken, hence the nuclear jets have been revealed - the spiral shapes around the nucleus.
Images were also obtained under service time on the Nordic Optical Telescope. Hugo Schwarz at the NOT is thanked for his help in arranging this. This image shows one of the nuclear fragements which detached from the comet's nucleus.
For news of Comet Hyakutake and a multitude of images, visit Ron Baalke's Hyakutake Page at JPL.
ghj@nojunk-removethis-mssl.ucl.ac.uk
ace Plasma Physics Group, Mullard Space Science Laboratory,
Holmbury St. Mary, Dorking, Surrey, RH5 6NT, United Kingdom
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