make particles stick to a moving target

I am making a 2d shooter and I use Raycast for my gun. If target is hit it creates particles at that location. My question is how to I make particles stick to a moving target???
Gun Code:

Var Gun: GameObject;
var FireDelay: float = 0.0;
var BulletPrefab : GameObject;
private var WeaponTimer : float = 0.0;	
function Update () {
if ( Input.GetButton( "Fire1" ) && WeaponTimer >= FireDelay ) {	
weapon_Fire_Timer = 0.0;
var hit : RaycastHit;
if ( Physics.Raycast( Gun.transform.position, Gun.transform.forward, hit ) ) {
Instantiate( BulletPrefab, hit.point, Quaternion.LookRotation( hit.normal ) );
WeaponTimer += Time.deltaTime;

What i do is when i create the bullet as a prefab all i do is attach the particle effect to the bullet. Then when the bullet is created the particles are there also

Can make particles stick to the emitter by unchecking `Simulate in worldSpace`. Can make the emitter follow around what you shot by childing to it:

// untested javascript:
// [Edit: in response to comment]

// spawn the emitter and save a handle to it: 
var hitEffect = Instantiate( BulletPrefab, ... );

// hit.transform is the thing you hit.
// make the newly spawned emitter be a child of what you hit;
// Emitter should "stick" to the target and follow it around:
hitEffect.parent = hit.transform;