One day Schisler noticed something โ the mysterious blip appeared 4 minutes earlier than the day before. Four minutes meant a lot to the airman: before being stationed at Clear, he had been a navigator on a B-47 bomber, and he knew that stars rise 4 minutes earlier each night as a result of Earth's motion around the Sun.
Ok... I did not know this, by which I mean I'd never put a number on it. Four minutes.
Over the weekend, he drove 125 km to the University of Alaska at Fairbanks, where he met an astronomy professor who showed him the location of his source โ the Crab Nebula, some 6,300 light years from Earth.
That clinches it. Schisler definitely deserves credit at the very least as co-discoverer.