Epoch J2000.0 Equinox J2000.0 (ICRS)
|Right ascension||19h 21m 44.79808s|
|Declination||+21° 53′ 01.8288″|
|Radius||~1.4 × 10-6 R☉|
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 (in July 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 nick-named "LGM-1" (for "Little Green Men").
LGM-1 discovery 
Little green men 1 (LGM-1) was the explanation given to a certain astronomical observation. In 1967, a radio signal was detected in a UK observatory by Jocelyn Bell and Antony Hewish. The signal had a 1.337302088331 second period and 0.04 second pulsewidth. It originated at celestial coordinates 19h 19m right 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 spurious noise, but this hypothesis was promptly discarded. After that, the discoverers proposed an alternative explanation that the signal might be a beacon or a communication from an intelligent extraterrestrial civilization and named it LGM-1 (LGM = "Little Green Men").
The signal turned out to be radio emissions from the pulsar CP1919, the first one recognized as such. Bell noted that other scientists could have discovered pulsars before her, but their observations were either ignored or disregarded. Researchers Thomas Gold and Sir Fred Hoyle identified this astronomical object as a rapidly rotating neutron star immediately upon their announcement.
Before the nature of the signal was determined, the researchers, Bell and her Ph.D supervisor Antony Hewish, somewhat seriously considered the possibility of extraterrestrial life:
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?
Nobel Prize controversy 
Cultural reference 
See also 
- Quasar CTA 102, initially postulated by Dr. Nikolai S. Kardashev to be a potential signal from an extraterrestrial civilization.
- Wow! signal
- The Optical Gravitational Lensing Experiment. Additional Planetary and Low-Luminosity Object Transits from the OGLE 2001 and 2002 Observational Campaigns, A. Udalski, G. Pietrzynski, M. Szymanski, M. Kubiak, K. Zebrun, I. Soszynski, O. Szewczyk, and L. Wyrzykowski, Acta Astronomica 53 (June 2003), pp. 133–149.
- "The ATNF Pulsar Catalogue". Retrieved 2010-02-11.
- Arzoumanian, Z.; Nice, D. J.; Taylor, J. H.; Thorsett, S. E. (1994). "Timing behavior of 96 radio pulsars". Astrophysical Journal 422 (2): 671. Bibcode:1994ApJ...422..671A. doi:10.1086/173760.
- S. Jocelyn Bell Burnell (1977). "Little Green Men, White Dwarfs or Pulsars?". Cosmic Search Magazine. Retrieved 2008-01-30. (after-dinner speech with the title of Petit Four given at the Eighth Texas Symposium on Relativistic Astrophysics; first published in Annals of the New York Academy of Science, vol. 302, pages 685-689, Dec., 1977)
- "Unknown Pleasures". Joy Division. June 1979. Retrieved 2008-07-05.
Further reading 
- Hewish, Antony; Bell, S. J.; Pilkington, J. D. H.; Scott, P. F.; Collins, R. A. (24 February 1968). "Observation of a Rapidly Pulsating Radio Source" (PDF). Nature 217 (5130): 709–713. Bibcode:1968Natur.217..709H. doi:10.1038/217709a0. Retrieved 2007-07-06.
- The discovery
- Article about Nobel Prize Controversies