Comet 21P/ Giacobini Zimmer
Bright comets are quite rare, but when one of these vagabonds passes our earth, it is a totally exciting thing - especially if you have a large telescope.
Things got exciting in the summer of 2018 when the periodic comet 21P/ Giacobini- Zinner entered the inner solar system. Predictions suggested a bright
comet, although predictions of brightness should always be taken with a bit of caution. For periodic comets, however, the parameters are well known because
they usually do not approach the Sun for the first time. And so it happened that the maximum brightness of 21P was about 7mag - bright enough to see it in
binoculars.
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In the eyepiece of my 20 inch telescope a bright and impressive comet appeared with a great tail, the end of which was pointed. At higher magnification a so called
"false nucleus" was visible in the center of the coma, the comet's head. This is not the nucleus of the comet, but just the very dense inner region of the coma.
With such bright comets it is worth to look with 50cm aperture if the comet shows color. And so it was here. At low magnification I could perceive a very pale
green. A great thing!
