O nose you've just been shot at oh crap I'm going to die in 5, 4, 3, 2, 1, wait?
This guide will give you tips for evading missiles and firing back, should you have any.
First off, when you hear that alarm, drop everything, and go at or above lightspeed.
Next, try and get a look at the object that's just fired at you. Examine its heading closely. Try and see if you can counter it.
In other words, head the opposite direction relative to where its headed.
Next, see if you can fire back with a warhead or two. If you don't have any warheads, just focus on evading.
Wait a while. The missiles tend to chase targets for a good period of time, at least a good 5 minute chase.
After that time, two things can happen. If you have managed to outrun it, you can simply relax, but don't head in the direction of the missile, it could still be trying to catch up. If you suddenly find yourself and your ship shaking violently, you can take it that you didn't manage to outrun the missile.
Oh, and yeah. Missiles are, no joke. They do 1000 damage to whatever they hit. And shields do not protect you, and yes, they can take out components.
After a while the alarm is still playing and you know you've outrun it, go ahead and reconnect.
Then, somewhere down the road, you may be able to get revenge on the person who shot at you.
Hope this helps.