ANALYSIS OF THE TAIL STRUCTURES OF COMET 1 P / HALLEY 1910 II

For the purpose of identifying, measuring, and correlating the morphological structures along the plasma tail of 1P/Halley, 886 images from September 1909 to May 1911 are analysed. These images are from the Atlas of Comet Halley 1910 II (DONN; RAHE; BRANDT, 1986).


INTRODUCTION
This work is based on a systematic analysis of images of 1P/Halley comet collected during its penultimate approach.
The entire database consists of 1006 images of the comet observed from 11 September 1909 to 30 May 1911.
These images were usually obtained with telescopes of large angular field, showing specially the tail morphology.

OBJECTIVES & DATA
For the purpose of identifying, measuring and correlating the morphological structures along the plasma tail of 1P/Halley 886 images from September 1909 to May 1911 are analysed.
These images are from the Atlas of Comet Halley 1910 II (DONN; RAHE; BRANDT, 1986).They were obtained through original photographic plates or good film copies of originals from the observatories and also through reproduced copies of images from journals.

Image Analysis
A systematic visual analysis revealed: • 304 wavy structures along the main tail, which corresponds to 34.31% of all analysed images • 164 wavy structures along the secondary tails (18.51%) • 41 solitary waves (solitons = kinks) (4.63%) • 13 Swan-like tails (1.47%) • 26 disconnection events (DEs) (2.93%) • 166 knots (regions of higher density of matter) (18.74%) • 6 shells (0.68%) In general, it is possible to associate the occurrence of a DE and/or a Swan-Tail with the occurrence of a knot, but the last one may occur independently.
It is also possible to say that the solitons occur in association with the wavy structures, but the reverse is not true.

CONCLUSIONS
The analysis of the 886 selected images showed that, in general, the DEs and/or the Swan-Tails occur in association with the knots, but the knots may occur independently, and also it is possible to say that the solitons occur in association with the wavy structures, but the reverse is not true.
The plasma of an individual DE is assumed to move away from the cometary nucleus most of time with a constant velocity.Such a velocity however varies broadly from one DE to another.In the all 886 analysed images, 26 displayed DEs.The 26 observed DEs were related to two onsets of DEs.
The amplituede A as well as the corrected wavelength λc of the wavy structures and solitons, both tend to increase as the corrected cometocentric distance dc increases.These results agree with the earlier research from Voelzke and Matsuura (1998) The mean value of the corrected wavelength λc measured in 70 different wavy structures is equal to: λc = (1,7 ± 0,1) x 10 6 km And the mean amplitude A of the wave (measured in the same 70 wavy structures) is equal to: A = (1,4 ± 0,1) x 10 5 km The average value of the corrected velocities Vkc of the knots measured in 36 different images is equal to: Vkc = (128 ± 12) km/s The 26 DEs documented in 26 different images allowed the derivation of two onsets of DEs, i.e., the time when the comet supposedly crossed a frontier between magnetic sectors of the solar wind (BRANDT; SNOW, 2000).Both onsets of DEs were determined after the perihelion passage with an average of the corrected velocities Vc equal to: Vc = (57 ± 15) km/s The mean value of the corrected cometocentric phase velocity Vpc measured in 20 different wavy structures is equal to: Vpc = (168 ± 28) km/s , which analysed comet 1P/Halley´s tail structures in its last apparition in 1986.The goals of this research are to report the results obtained from the analysis of the 1P/Halley´s 1910 II images, to provide empirical data for comparison with an earlier study of comet 1P/Halley in 1985-1986 (VOELZKE; MATSUURA, 1998) and to form the input for future physical/theoretical work.Observation: This text is a summary of the published work: Morphological Analysis of the Tail Structures of Comet P/Halley 1910 II (VOELZKE; IZAGUIRRE, 2012).