This vast 2.6 million year old supernova remnant is usually simply called "the Gum nebula
". Located at the collision between the Gould Belt and the Vela region, the Gum nebula is a major part of the local galaxy.
The Gum nebula is too large to easily create an image of it using either SuperCOSMOS or the Digitized Sky Survey, so this image was taken from Douglas Finkbeiner's composite hydrogen-alpha image
of the entire Milky Way.
Gum's 12a boundary box surrounds only the bright emission towards the centre of the Gum nebula. More sensitive hydrogen-alpha observations have only recently mapped the full boundary of the Gum nebula, which has an extent in the southern sky several thousand
times larger than the full moon!
This recent article looks at the interaction of the Gum nebula with numerous objects in its interior including the Vela supernova remnant. [1
The Gum nebula is a 2.6 million year old supernova remnant. [2
1. ^ Sushch, I., Hnatyk, B., & Neronov, A. (2011). "Modeling of the Vela
complex including the Vela supernova remnant, the binary system γ2
Velorum, and the Gum nebula", Astronomy and Astrophysics, Vol. 525, A154.
2. ^ Dubner, G., Giacani, E., Cappa de Nicolau, C., et al. (1992). "A study of
the neutral hydrogen in direction to the GUM nebula", Astronomy and
Astrophysics Supplement Series, Vol. 96, 505-523. [1992A&AS...96..505D]