Hello guys!
I need some help to create an arrow who emit light

Here is the problem, I've made my arrow meshe, and there is a little orb at the end
I would like to show you with screens but it says that I'm not allowed to post links...
Now what I want is when I throw this arrow the orb starts to emit a bright light to illuminate the area, but I don't know who to do it.
If someone know how to bring light on a meshe like my arrow, it would be great.
Thank you in advance for your help.

PS : Sorry for my english...