21P Giacobini-Zinner
 

Closest to Earth 2018 Sep 10 at 0.39AU
Closest to Sun 2018 Sep 10 at 1.01AU
Maximum Magnitude 7 in Sep 2018
Period 6.55 years

21P was another periodic comet that had a very favourable apparition in 2018 as it was closest to the Earth and Sun on the same day of September 10.
During August, the comet was restricted to northern observers.
By the first week in September, the magnitude 7 comet came into view for southerners, trekking southwards through Auriga in the hour before dawn.
The comet trekked through Gemini, Monoceros and Canis Major, whilst fading to magnitude 9 by the end of October.

Above: 21p Giacobini-Zinner rendezvous with the Seagull Nebula in Canis Major on 2018 October 11
 

21p Giacobini-Zinner on 2018 September 20. Dust tail appears >1 degree long in this image.


Wide field image of 21p Giacobini-Zinner on 2018 September 13 with star clusters M35 at top right and M37 at lower left.


21p Giacobini-Zinner on 2018 September 13 with star clusters M35 and NGC 2158 at right

21P Giacobini-Zinner. 2018 September 13 at 19UT. Visual magnitude 7.4, dia 7', DC6, tail 20' in PA280. 25x100mm binoculars.