Premise: PSR B1919+21 is a pulsar with a period of 1.3373 seconds and a pulse width of 0.04 seconds. Discovered by Jocelyn Bell Burnell and Antony Hewish on November 28, 1967, it is the first discovered radio pulsar. The power and regularity of the signals were briefly thought to resemble an extraterrestrial beacon, leading the source to be nicknamed LGM-1 (for "little green men").
Hypothesis: Antony Hewish and Jocelyn Bell Burnell discovered the PSR B1919+21 pulsar, which at first resembled an extraterrestrial beacon.