21P/Giacobini–Zinner is a periodic comet, which was discovered by Michel Giacobini on December 20, 1900. It was recovered two passages later by Ernst Zinner on October 23, 1913. During its apparitions, Giacobini–Zinner reaches about the 8th magnitude, but in 1946 it underwent a series of outbursts that made it as bright as 5th magnitude. It is the parent body of the Draconids meteor shower (also known as Giacobinids). The comet nucleus is estimated to be 2.0 kilometers in diameter. This image shows the comet on September 17th 2018 at 00:30 UT, between NGC 2174 (Monkey Head Nebula) and IC 443 (Jellyfish Nebula). This is a four panel mosaic. The images of the comet and NGC 2174 were obtained on 17. Sep., the upper left and right panel - on 19. Sep. Individual panels could be seen on the following pages: 21P near NGC 2174 and 21/P near IC 443 .