Remember NuSTAR, the specialized space telescope NASA designed specifically to study black holes? It just found something much, much brighter. Astronomers at NASA have stumbled upon what appears to be the most luminous pulsar ever discovered, but they almost mistook it for a black hole. After measuring the dead star's output, they found it was outputting as much energy as 10 million suns -- shockingly powerful, considering how much smaller it is than our own star. Astronomers aren't sure why the pulsar is so bright, but will continue to study in hopes of learning how common or uncommon this kind of pulsar is. The discovery kind of shakes up what theorist knew about black holes and ultraluminous x-rays, underlining how little we really know about the universe out there. Check out NASA's gallery of images at the source link below.