Morphological analysis of the tail structures of comet P/Halley 1910 II

Author(s)

Voelzke, M. R. ^[1] ; Izaguirre, L. S. ^[1]

Affiliation

^[1] Univ Cruzeiro Sul, BR-03342000 Sao Paulo - Brazil

• Document type: Journal article
• Source: Planetary and Space Science; v. 65, n. 1, p. 104-108, MAY 2012.
• Web of Science Citations: 8

Abstract

For the purpose of identifying, measuring and correlating the morphological structures along the plasma tail of P/Halley 886 images from September 1909 to May 1911 are analysed. These images are from the Atlas of Comet Halley 1910 II (Donn et al., 1986). A systematic visual analysis revealed 304 wavy structures along the main tail and 164 along the secondary tails, 41 solitary waves (solitons), 13 Swan-like tails, 26 disconnection events (DEs), 166 knots (regions of higher density of matter) and six shells. While the wavy structures denote undulations or a train of waves, the solitons refer to the formations usually denominated as kinks. 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. The 26 DEs documented in 26 different images allowed the derivation of two onsets of DEs (Table 1), i.e., the time when the comet supposedly crossed a frontier between magnetic sectors of the solar wind (Brandt and Snow, 2000). Both onsets of DEs were determined after the perihelion passage with an average of the corrected velocities V-c equal to (57 +/- 15) km s(-1). The mean value of the corrected wavelength lambda(c) measured in 70 different wavy structures is equal to (1.7 +/- 0.1) x 10(6) km and the mean amplitude A of the wave (measured in the same 70 wavy structures cited above) is equal to (1.4 +/- 0.1) x 10(5) km. The mean value of the corrected cometocentric phase velocity V-pc measured in 20 different wavy structures is equal to (168 +/- 28) km s(-1). The average value of the corrected velocities V-kc of the knots measured in 36 different images is equal to (128 +/- 12) km s(-1). There is a tendency for A and lambda(c) to increase with increasing cometocentric distance. The results of this work agree with the earlier research from Voelzke and Matsuura (1998), which analysed comet P/Halley's tail structures in its last apparition in 1986. (C) 2012 Elsevier Ltd. All rights reserved. (AU)