35 Years ago in 1979, Stephen Morris suggested to graphic designer Peter Saville that he use an image from The Cambridge Encyclopaedia of Astronomy for Joy Division’s upcoming LP Unknown Pleasures. Saville took the image of Pulsar CP 1919, reversed the colors to be white on black, and then had it printed on a textured card. This ultimately resulted in the creation one of the greatest sleeves of all time, for one of the greatest albums of all time.
But…exactly what is Pulsar CP 1919? It has more significance than most people realize. In fact, It was actually the first Pulsar observed! On November 28th, 1967 Jocelyn Bell Burnell and Antony Hewish observed pulses of radio waves separated by 1.33 seconds that originated from the same location on the sky in the constellation Vulpecula. Looking for explanations for the pulses they determined it could not be a man-made radio frequency interference, or instrumental effects. Despite doubting they found a radio signal from an alien civilization, they nicknamed the signal LGM-1, an abbreviation of “little green men“. Their pulsar was officially dubbed CP 1919 (Cambridge Pulsar 1919, with the “1919” being the Pulsar’s right ascension).
The word “pulsar” is a contraction of “pulsating star”, with the star in this case being a Neutron Star, a tiny city-sized star comprised primarily of neutrons resulting from the gravitational collapse of a massive star during a supernova. The pulsing occurs because the electromagnetic radiation is projected in beams (not unlike a lighthouse) emitted from the highly magnetized, rapidly rotating star, which are only visible when they are in our line of sight on Earth.
Because of this discovery, In 1974, Antony Hewish became one the first astronomers to be awarded the Nobel Prize in physics. Sadly, Jocelyn Bell, who made the initial discovery while she was Hewish’s Ph.D student, was not awarded the prize.
The image that we now see representing CP 1919 in the 1977 edition of The Cambridge Encyclopaedia of Astronomy is a stacked timing profile used to analyze the subpulse structures for patterns, which to the credit of Peter Saville and Stephen Morris, is expression of lonely beauty touching from a distance.