As an example, I just lost about 10 minutes ago in a (celestial) sector 3 while attempting to destroy a station. I warped in, saw the station + 3 ships. Two of the three ships had one celestial death ray, and despite warping in fairly far away from the station and 2 of the ships, two death rays were still able to reach me.
Luckily, one got distracted by my drones, and I made it back out after destroying one of their ships.
I repair and warp back in. Again, station + 3 ships, two of which have a celestial death ray. Luckily, one of them is too far away. I destroy 2 ships, but am forced to warp out and repair.
I repair and warp back in a third time. Again, station + 3 ships, this time all 3 have celestial death rays. They target my main ship and fire. I see what's happening, and attempt to move my other two ships to shield it and spread the damage, but before my other two ships can move in front of my main, it's already exploded, and it's game over.
I actually had two celestial death rays of my own, but it wasn't enough
I should mention that I did attempt to lure the ships out with distress beacons first, but it didn't work.
It's frustrating to lose like this because it feels like there's no counter-play. I can't really out-distance them. Warping in close (to make use of effective short ranged weapons) is usually suicide, as it lets them strip shields quickly with other weapons, allowing the death rays to tear into my hull even sooner. Drones can sometimes distract one or two enemy ships, but this is unreliable and doesn't work on a group. Luring the enemy out with distress beacons doesn't seem to work. Even having two of my own celestial death rays wasn't nearly good enough.
Right now, it feels like my best shot at victory is to get lucky enough to not run into a celestial sector 2 or 3.