|Designation|| GUM 16|
|Right ascension||08h 33m|
|Type of object||Supernova remnant|
|Distance from Earth||800 ly|
The Vela supernova remnant (GUM 16, SNR G263.9-03.3) is a supernova remnant in the constellation of Vela. The nebula's structure consists of a central pulsar surrounded by glowing filaments of hot gas. It is thought by some that the Vela supernova remnant is embedded in an older supernova remnant known as the Gum nebula. The nebula is believed to lie around 800 light years away. At this distance, its apparent size of 8° corresponds to a physical size of 0.31 ly.
The Vela pulsar (sometimes referred to as Vela X) is a rapidly rotating neutron star, and as such is extremely dense. Observed by NASA's Chandra Observatory, it is approximately 12 miles in diameter and completes 11 revolutions per second. This means the outer parts of its surface are travelling at 80% the speed of light. The star has been seen to be emitting jets of particles moving a great speed from its poles. These appear similar to a rotating helix, suggesting the pulsar precesses (or wobbles) as it spins.