Gum 12, also known as the Vela Supernova Remnent, is the most famous object in the catalogue of Colin Gum, an Australian astronomer who, in the 1950's made extensive photographic studies of the southern Milky Way. Gum 12 is usually just refered to as "The Gum Nebula".
The Vela supernova remnent is a very large object, covering nearly 40 square degrees with very faint filaments. It can be a real challenge to observe the filaments visually unless the skies are very dark. In the image above 2 faint traces of filaments can be seen. One arcing from the top left, through the centre, to the bottom right, and the other near the top right corner. The image is centred on RA 8h 30m Dec -45d 28'.
The image below is centred on RA 8h 29m Dec -44d 06'. Here the is a faint arc curving down towards the centre from the upper right.