162P - P/2004 TU12 (Siding Spring):
The tail activity reported by Masi et al. (IAUC 8439) was due to a major tail disconection event that was originally detected by Montserrat Campas in images taken by Ramón Naves (Observatorio de Montcabre, Barcelona) on 2004 Nov. 14.743 with a 0.30-m Schmidt-Cassegrain. The tail was brightest around the disconnection and very faint from there to the nucleus. The separation of the disconnection increased from 36" on Nov. 14.74767 to 69" on Nov. 14.85407. Images taken on Nov. 15.75 show that the tail was extremely faint and particularly so close to the nucleus, but had brightened significantly on Nov. 16.75. On Nov. 17.8 no obvious tail was visible even on a half hour exposure tracked on the comet.
Juan Lacruz (La Canada, Madrid) also observed a 0.5
magnitude
brightening of the inner coma (10" aperture) between 2004 Nov. 12.78
and
12.92, although the overall trend in the light curve based on 44
photometric
measures made by Lacruz, Naves, Diego Rodriguez (Madrid), Julio
Castellano
(Observatorio de Rodano, Valencia) and Esteve Cortes (Observatorio de
Mataro,
Barcelona) between Nov. 12.75 and 16.8 is a slight fade with Afrho
decreasing
from 190+/-13-cm on Nov. 12.75 to 135+/-6-cm on Nov. 16.8.