Imagine that you see an enormous explosion out in space. This explosion puts out a total energy of 1044 J, and lasts for a week. Detailed observations show that this explosion did not blast any gas into space, even though there was plenty of hydrogen close to the exploding object. What is the minimum possible mass of the thing that exploded (in kg)? You may assume that G=6.67×10−11N m2 kg−2 , c=3.0×108m s−1 , mp=1.67×10−27kg , h=6.63×10−34m2 kg s−1 and σT=6.7×10−29m2 . You may also assume that the explosion had a constant brightness throughout the week.