Fourth Cambridge Survey

Organization	Mullard Radio Astronomy Observatory
Wavelength	178 MHz radio
Data sources	4C Array, Mullard Radio Astronomy Observatory
Goals	Deep survey of radio sources
Data products	4C Catalogue
Telescopes	4C Array
Website	vizier.cfa.harvard.edu/viz-bin/VizieR-3?-source=VIII%2F4&-out.max=50&-out.form=HTML

The Fourth Cambridge Survey (4C) is an astronomical catalogue of celestial radio sources as measured at 178 MHz using the 4C Array. It was published in two parts, in 1965 (for declinations +20 to +40) and 1967 (declinations -7 to + 20 and +40 to +80), by the Radio Astronomy Group of the University of Cambridge. References to entries in this catalogue use the prefix 4C followed by the declination in degrees, followed by a period, and then followed by the source number on that declination strip, e.g. 4C-06.23.

The 4C Array, which used the technique of aperture synthesis, could reliably position sources with flux densities of around 2 Jy, to within about 0.35 arcmin in Right ascension and 2.5 arcmin in declination.

References

• Pilkington, JDH; Scott, PF (1965). "A survey of radio sources between declinations 20° and 40°". Memoirs of the Royal Astronomical Society. 69: 183. Bibcode:1965MmRAS..69..183P. 
• Gower, JFR; Scott, PF; Wills, D (1967). "A survey of radio sources in the declination ranges −07° to 20° and 40° to 80°". Memoirs of the Royal Astronomical Society. 71: 49. Bibcode:1967MmRAS..71...49G.