Spatial differences in the visible/near infrared continuum emission of Comet C/1995 O1 (Hale-Bopp)
Received 31 October 1997 / Accepted 27 November 1997
Imaging spectroscopy data in the 0.4-1 µm spectral region of comet Hale-Bopp have been analysed in order to study the spatial distribution and physical properties of the dust grains in the coma. The data presented cover a period of three days close to perihelion. The spectra have been processed by means of the principal component analysis in order to individuate coherent spatial units with different spectral properties. The study shows the presence of two regions on the sunward and antisunward sides of the nucleus exhibiting different continuum emissions. This fact is interpreted as due to the presence of dust grains of diverse compositions and/or sizes. In the latter hypothesis, the observations could be explained by size sorting due to solar radiation pressure.
Key words: comets: general comets: individual: C/1995 O1 (Hale-Bopp) solar system: formation techniques: spectroscopic
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© European Southern Observatory (ESO) 1998
Online publication: April 15, 1998