In summary, the enormous scale of the megaburst is a result of the fact that the jettisoned layer was extremely poorly cemented and disintegrated in a cataclysmic manner. Thus, one may expect a potential inverse relationship between the prominence of an outburst and the appearance of persistent companion nuclei. Except for the amplitude, the 17P event was similar to the outbursts of 29P/Schwassmann-Wachmann (e.g., in the shape of the light curve; cf., e.g., Beyer 1962, Astron. Nachr. 286, 219), which, likewise, has never been observed to split. On the other hand, the brightness in the outbursts experienced by comet 41P/Tuttle-Giacobini-Kresak in 1973 (e.g., Sekanina 1984, Icarus 58, 81) subsided very rapidly, suggesting a different mechanism (probably involving only gas). It will be interesting to see whether 17P is subjected to a second outburst in early January, as in 1892. A. Fitzsimmons reports the following corrected R magnitudes for the nuclear condensation of 17P/Holmes in a 2" aperture (cf. the report by Snodgrass et al. on CBET 1111): Oct. 25.52 UT, 6.6; 25.55, 6.7; 26.40, 8.0; 26.45, 8.1; 28.15, 9.4; 28.43, 9.5.
Central Bureau Electronic Telegrams
- Pub Date:
- November 2007