The peak luminosity of a white dwarf supernova is around 1010 Lsun, and it remains brighter than 108 Lsun for about 150 days. In comparison, the luminosity of a bright Cepheid variable star is about 10,000 Lsun. The Hubble Space Telescope is sensitive enough to make accurate measurements of apparent brightness for Cepheid variable stars up to a distance of about 100 million light-years. Estimate the distance of a fading white dwarf supernova of luminosity 108 Lsun whose apparent brightness is comparable to that of a bright Cepheid variable star 100 million light-years from Earth. How does the distance of that supernova compare to the size of the observable universe?