This a project that my friend, J. Mattei and I did together. He captured the images and I processed them.

There is almost no information about GUM-25, what I could put together is sumarized below:

This HII region appears to be part of the Vela OB1 association and according to Avedisova is ionised by the O9 V star CD - 48 4352.
Images taken in IR, reveals a spectacular bubble structure. This infrared image strips away the dust surrounding this nebula and shows the central star cluster.
Althoug SIMBAD and the RCW catalog identify RCW 40 and Gum 25 as the same object, there is a limited accuracy of Gum's coordinates. However, there is an unusually large distance between the two sets of coordinates suggesting the possibility that they are distinct.
To get more information go here: http://galaxymap.org/cat/view/gum/25