Context : X-ray observations have unveiled the existence of enigmatic point-like sources at the center of young ( a few kyrs ) supernova remnants .
These sources , known as Central Compact Objects ( CCOs ) , are thought to be neutron stars produced by the supernova explosion , although their X-ray phenomenology makes them markedly different from all the other young neutron stars discovered so far .

Aims : The aim of this work is to search for the optical/IR counterpart of the Vela Junior CCO and to understand the nature of the associated H _ { \alpha } nebula discovered by Pellizzoni et al .
( 2002 ) .

Methods : We have used deep optical ( R band ) and IR ( J,H,K _ { s } bands ) observations recently performed by our group with the ESO VLT to obtain the first deep , high resolution images of the field with the goal of resolving the nebula structure and pinpointing a point-like source possibly associated with the neutron star .

Results : Our R -band image shows that both the nebula ’ s flux and its structure are very similar to the H _ { \alpha } ones , suggesting that the nebula spectrum is dominated by pure H _ { \alpha } line emission .
However , the nebula is not detected in our IR observations , whick makes it impossible to to constrain its spectrum .
A faint point-like object ( J \geq 22.6 , H \sim 21.6 , K _ { s } \sim 21.4 ) compatible with the neutron star ’ s Chandra X-ray position is detected in our IR images ( H and K _ { s } ) but not in the optical one ( R \ga 25.6 ) , where it is buried by the nebula background .

Conclusions : The nebula is most likely a bow-shock produced by the neutron star motion through the ISM or , alternatively , a photo-ionization nebula powered by UV radiation from a hot neutron star .
A synchrotron nebula , powered by the relativistic particle wind from the neutron star , is the less likely interpretation because of its non-detection in the X-rays and of the apparent lack of continuum emission .
The candidate CCO counterpart could be the neutron star itself , a fallback disk left over from the supernova explosion , or a mid M-type star , or later , at a distance of 2 kpc .