Nuclei A and B of 205P/Giacobini
This is an image of Comet Giacobini which has been broken
up into three fragments.
Bright nucleus A is 16th magnitude (total magnitude) and nucleus B, which has broken off nucleus A is very faint at 19.9 magnitude (magnitude of nucleus). The other nucleus C is farther west and not in the image. With data on nuclei B and C building up, calculations will gradually become more accurate to work out when the comet broke up.
Giacobini orbits the sun in about 6.7 years, but hadn't been
observed for 111 years leading to the speculation that it might have become
extinct. Koichi Itagaki (Yamagata city) and Hiroshi Kaneda (Sapporo city)
co-discovered a 13th-magnitude comet on September 10 and it turned out
to be Giacobini. Will it become a phantom comet again after the end of
this sudden and huge outburst? At Geisei we have been following this comet
with great interest.
