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Detection of Anisotropy in the Cosmic Blackbody Radiation

Phys. Rev. Lett. 39, 898 – Published 3 October 1977
G. F. Smoot, M. V. Gorenstein, and R. A. Muller


We have detected anisotropy in the cosmic blackbody radiation with a 33-GHz (0.9 cm) twin-antenna Dicke radiometer flown to an altitude of 20 km aboard a U-2 aircraft. In data distributed over two-thirds of the northern hemisphere, we observe an anisotropy which is well fitted by a first-order spherical harmonic with an amplitude of (3.5 ± 0.6) × 10-3 °K, and direction [11.0 ± 0.6 h right ascension (R.A.) and 6° ± 10° declination (dec)]. This observation is readily interpreted as due to motion of the earth relative to the radiation with a velocity of 390 ± 60 km/sec.

DOI: http://dx.doi.org/10.1103/PhysRevLett.39.898

  • Received 6 July 1977
  • Published in the issue dated 3 October 1977

© 1977 The American Physical Society

Authors & Affiliations

G. F. Smoot, M. V. Gorenstein, and R. A. Muller

  • Lawrence Berkeley Laboratory and Space Sciences Laboratory, University of California, Berkeley, California 94720

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