Tags: Star.
PSR B1919+21 is a pulsar with a period of 1.3373 seconds and a pulse width of 0.04 second. It was the first radio pulsar discovered (on November 28 1967 by Jocelyn Bell Burnell and Antony Hewish). The power and regularity of the signals was thought to resemble a beacon so for a time the source was nicknamed LGM-1 (for Little Green Men).The original designation of this pulsar was CP 1919 and it is also known as PSR J1921+2153. It is located in the constellation of Vulpecula.