The temperature of the surface of the sun is nearly \(6000~\text{K}\) and the amount of total energy emitted by the sun per second is \(4\times10^{26}~\text{J}\). If the temperature of the surface of the sun were \(18000~\text{K}\), then the amount of thermal radiation emitted by the same will be:
1. \(3.24\times10^{28}~\text{W}\) 
2. \(2.52\times10^{28}~\text{W}\) 
3. \(8\times10^{26}~\text{W}\) 
4. \(16\times10^{27}~\text{W}\)