RayCast 2d change start position ?

Hi, I need to be able to change the position of start rayCast position. I'n my case the rayCast start from the middle of the object and goes down. I need it starts far from middle position.

         RaycastHit2D hitDown = Physics2D.Raycast(transform.position, Vector2.down);   
         if (hitDown.collider != null)
         {
             Debug.DrawRay(this.transform.position, Vector2.down * 1, Color.yellow);
             Debug.Log("Did Hit down: " + hitDown.collider.name);
         }