Vector 3. Slerp

Hi, i want to change the speed variable of Vector3.Slerp but when i do it, it changes the position because there is a transform.

Tried:

1- If you change the number only when the game start, it works perfectly.

2- I was trying to save the variable just a moment before changing the speed and apply it to the position, but it seems it doesn't work or it do weird things.

The thing i want to get

Changing the Vector3.Slerp velocity without changing the position.

FIRST CODE WITHOUT CHANGING ANYTHING:

Code:

 var TimeSpeed : float = 1;
 var Sun : GameObject;
 var sunrise : GameObject;
 var sunset : GameObject;
 
   var center = (sunrise.position + sunset.position) * 0.5;
         // move the center a bit downwards to make the arc vertical
         center -= Vector3(0,0.1,0);
     
         // Interpolate over the arc relative to center
         var riseRelCenter = GeneralSettings.Helpers.sunrise.position - center;
         var setRelCenter = GeneralSettings.Helpers.sunset.position - center;
 
 fracComplete = fracComplete*TimeSpeed;
 Sun.transform.position =  
 
 Vector3.Slerp(riseRelCenter, setRelCenter, fracComplete);
 LightSettings.Sun.transform.position += center;

SECOND CODE MODIFIED:

    var TimeSpeed : float = 1;
     var Sun : GameObject;
     var sunrise : GameObject;
     var sunset : GameObject;
     
       var center = (sunrise.position + sunset.position) * 0.5;
             // move the center a bit downwards to make the arc vertical
             center -= Vector3(0,0.1,0);
         
             // Interpolate over the arc relative to center
             var riseRelCenter = GeneralSettings.Helpers.sunrise.position - center;
             var setRelCenter = GeneralSettings.Helpers.sunset.position - center;
     
     fracComplete = fracComplete*TimeSpeed;
     Sun.transform.position =  
     
     Vector3.Slerp(riseRelCenter, setRelCenter, fracComplete);
     LightSettings.Sun.transform.position += center;
 
         
            if(timeSpeed2 == !ActualTimeGame.timeSpeed  && change2 == true){
            print("Bien hasta aquí");
            fracComplete = fracComplete*ActualTimeGame.timeSpeed;
         LightSettings.Sun.transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, fracComplete);
         LightSettings.Sun.transform.position += center;
            }
                frac2 = fracComplete;
            
         
        
   if(ActualTimeGame.timeSpeed != timeSpeed2){
     frac = fracComplete;
     return;
    if(!oneTimeFrac){
             oneTimeFrac = true;
             timeSpeed2 = ActualTimeGame.timeSpeed;
             change= true;
             fracComplete = frac;
             change2=true;
     }

Thanks in advance, KirbyRawr. PD: the codes can contain some errors.