PSR B1919+21

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**PSR B1919+21**
Observation data Epoch J2000.0 (ICRS)
Constellation (pronunciation)	Vulpecula
Right ascension	19^h 21^m 44.79808^s^[1]
Declination	+21° 53′ 01.8288″^[1]
Astrometry
Spectral type	Pulsar
Apparent magnitude (V)
Distance	2283.12 Ly
Binary orbit
Period (P)	1.3373^[2] s ^[2]
Details
Mass	? M_☉
Radius	? R_☉
Luminosity	? L_☉
Temperature	? K
Metallicity	?
Rotation	1.337
Age	7.20 years
Other designations
PSR J1921+2153, PULS CP 1919+21, WSTB 12W15, PSR B1919+21, PULS CP 1919.

PSR B1919+21 is a pulsar with a period of 1.337 seconds and a pulse width of 0.04 second. It is notable for being the first radio pulsar ever discovered (in July 1967 by Jocelyn Bell Burnell). Its original designation was CP 1919 and it is also known as PSR J1921+2153. It is located in the constellation of Vulpecula.

1 Discovery
2 Notes
3 References
4 See also
5 External links

[edit] Discovery

Before the nature of the signal was determined, the researchers, Bell and her Ph.D supervisor Anthony 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?^[3]

The observation was given the half-humorous designation Little green men 1, until researchers Thomas Gold and Fred Hoyle correctly identified these signals as rapidly rotating neutron stars with strong magnetic fields.

When Hewish and Martin Ryle received the Nobel Prize in physics in 1974 for their work in radio-astronomy and pulsars, it was argued by Hoyle that Burnell should have been a co-recipient of the prize.

The British post-punk band Joy Division used an image of CP 1919's radio pulses on the cover of their debut album, Unknown Pleasures.^[4]

[edit] Notes

^ ^a ^b 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.
^ ^a ^b A planet-sized transiting star around OGLE-TR-122. Accurate mass and radius near the hydrogen-burning limit, F. Pont, C. H. F. Melo, F. Bouchy, S. Udry, D. Queloz, M. Mayor, and N. C. Santos, Astronomy and Astrophysics 433, #2 (April 11, 2005), pp. L21–L24.
^ S. Jocelyn Bell Burnell (1977). Little Green Men, White Dwarfs or Pulsars?. Cosmic Search Magazine. Retrieved on 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 on 2008-01-30.