The temperature at the back of a turbine jet engine varies significantly based on the engine type and operating conditions, particularly between high-bypass and low-bypass designs. For modern fighter jets, the exhaust temperatures can be quite high, but specific figures depend on the engine model and its operational state. A useful resource for understanding these variations is the Wikipedia page on jet engines, which provides detailed information on combustion temperatures and engine types. Users seeking precise data for calculations should consider the specific engine type they are examining. This information is essential for accurate experimentation and design calculations.