maybe its a hardpoint that connect to two turrets, or one beam behind he other that happened to fire at the same time and get deflected, they seem to get further apart a tiny tiny bit to the left, but it looks like a double beam
That is called casuality, it is just a beam weapon mounted in a double hardpoint, fired at the same time (as every beam multi hardpoint), the only casuality is the identical deflected beam angle
From what I see, the beams are slightly farther apart on the edge of the screen than where they hit the shields. It also looks like the left-side ships are Federation (hard to tell, since the only one in frame is in the middle of blowing up, but it looks like a Puma or Gazelle hull), in which case this could be a beam coming from the forward hardpoint of a Fox frigate - two turrets, really close together. At long range the two beams are very nearly parallel.
Yeah, it’s the good 'ol feds. And I agree now–they are slightly farther apart. But, based on the turret location (if it was a double beam), the beams actually could be farther apart at the end. As far as I know, the beams wouldn’t change their length to meet the other beam’s end. The turret would fire, and the top beam would go a biiiit further than the bottom one.