Make lens flare show up earlier then standard

I have a sprite that is representing the suns sphere. I then have a directional light that follows that sprite.

If I add a flare to the light, the flare only show up when the lights "center point" is in camera view.
This means that the flare do not show up until the suns sprites center is in camera view.

I would like the flare to show up directly when the suns sprite is entering the camera view.

Is this something that is possible, or do I need to make some sort of new shader for this?