 Chart on whichJocelyn Bell Burnell first recognised evidence of PSR B1919+21, exhibited atCambridge University Library | |
| Observation data EpochJ2000 (ICRS) EquinoxJ2000 (ICRS) | |
|---|---|
| Constellation | Vulpecula |
| Right ascension | 19h 21m 44.815s[1] |
| Declination | +21° 53′ 02.25″[1] |
| Characteristics | |
| Evolutionary stage | Pulsar |
| Astrometry | |
| Distance | 1000+2600 −700 ly (300+800 −200[2] pc) |
| Details | |
| Mass | ~1.4 M☉ |
| Radius | ~1.4 × 10−5 R☉ |
| Luminosity | 0.006[3] L☉ |
| Rotation | 1.3373021601895s[4] |
| Age | 16[3] Myr |
| Other designations | |
| PSR J1921+2153,PSR 1921+2153, PSR B1919+21, PSR 1919+21, WSTB 12W15,CP 1919+21, CP 1919,LGM-1 | |
| Database references | |
| SIMBAD | data |
PSR B1919+21 is apulsar with a period of 1.3373 seconds[4] and a pulse width of 0.04 seconds. Discovered byJocelyn Bell Burnell on 28 November 1967, it is the first discovered radio pulsar.[5] The power and regularity of the signals were briefly thought to resemble an extraterrestrialbeacon, leading the source to be nicknamedLGM, laterLGM-1 (for "little green men").[6]
The original designation of this pulsar wasCP 1919, which stands for Cambridge Pulsar atRA19h 19m.[7] It is also known asPSR J1921+2153 and is located in theconstellation ofVulpecula.
In 1967, a radio signal was detected using theInterplanetary Scintillation Array of theMullard Radio Astronomy Observatory inCambridge, UK, by Jocelyn Bell Burnell. The signal had a1.337302088331-secondperiod (not in 1967, but in 1991) and 0.04-secondpulsewidth.[4] It originated atcelestial coordinates19h 19mright ascension, +21°declination. It was detected by individual observation of miles of graphical data traces. Due to its almost perfect regularity, it was at first assumed to be spuriousnoise, but this hypothesis was promptly discarded. The discoverers jokingly named itlittle green men 1 (LGM-1), considering that it may have originated from an extraterrestrial civilization, but Bell Burnell soon ruled out extraterrestrial life as a source after discovering a similar signal from another part of the sky.[6]
The original signal turned out to be radio emissions from the pulsar CP 1919, and was the first one recognized as such. Bell Burnell noted that other scientists could have discovered pulsars before her, but their observations were either ignored or disregarded. ResearchersThomas Gold andFred Hoyle identified this astronomical object as a rapidly rotatingneutron star immediately upon their announcement.[citation needed]
Before the nature of the signal was determined, the researchers, Bell Burnell and her PhD supervisorAntony Hewish, considered the possibility of extraterrestrial life:[8]
We did not really believe that we had picked up signals from another civilization, but obviously the idea had crossed our minds and we had no proof that it was an entirely natural radio emission. It is an interesting problem – if one thinks one may have detected life elsewhere in the universe[,] how does one announce the results responsibly? Who does one tell first?
When Antony Hewish andMartin Ryle received theNobel Prize in physics in 1974 for their work inradio astronomy and pulsars,Fred Hoyle, Hewish's fellow astronomer, argued that Jocelyn Bell Burnell should have been a co-recipient of the prize.[9]
In 2018, Bell won the $3-MillionBreakthrough Prize in Fundamental Physics for her work.[10]
The Englishpost-punk bandJoy Division used an image of CP 1919's radio pulses on the cover of their 1979 debut album,Unknown Pleasures.[11][12][13]
German-born British composerMax Richter wrote a piece inspired by the discovery of CP1919 titledJourney (CP1919).[14]
The Englishindie rock bandArctic Monkeys used a sound based on the pulses in their music video for "Four Out of Five."[15][16][better source needed]
| Types | |
|---|---|
| Single pulsars |
|
| Binary pulsars | |
| Properties | |
| Related | |
| Discovery | |
| Satellite investigation | |
| Other | |
