At first glance I thought it must be the sun shining through the windows (or portholes?) but after closer examination it looks like it was done in post, possibly with masked white solids.
Try a test with a white solid that has a highly feathered elliptical mask on it - play with the scaling and transparency to get the timing of the effect right. You might want to get one of the flashes right, then copy and paste it before resizing it to get a bit of variation.
It doesn't look more complicated than that. I could be wrong though...
This could easily be done as Simon suggested.
Or you could use AE's built in lens flare effect somewhat colorized.
Or, ideally, you could use Knoll Light Factory Pro. The best lens flare effect out there. It is amazing.
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
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