A star initially has ${10}^{40}$ deuterons. It produces energy via the process ${ }_1^{2}H{+}_1^{2}H{\to }_1^{3}H+p$ and ${ }_1^{2}H{+}_1^{3}H{\to }_2^{4}He+n$ Where the masses of the nuclei are $m{(}^{2}H)=2.014$ amu, $m\left(p\right)=1.007$ amu, $m\left(n\right)=1.008$ amu and $m{(}^{4}He)=4.001$ amu. If the average power radiated by the star is ${10}^{16}W,$ the deuteron supply of the star is exhausted in a time of the order of