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Observations of a transient X-ray source with a period of 104 s

Naturevolume 256pages628630 (1975) | Download Citation



DURING routine observations of the Crab Nebula by Ariel V, experiment A, the rotation modulation collimator (RMC), discovered a new X-ray source A0535+26. The source was just detectable during the first observation on April 13, and during the 16 d of observation was seen to brighten to nearly twice the Crab's intensity (in the 3–7 keV range). The source varies periodically, with a period of 104 s, and has a very flat spectrum in the 3–7 keV range.

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  1. 1

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  1. Mullard Space Science Laboratory, University College, London, UK

  2. Department of Space Research, University of Birmingham, UK

    • C. J. EYLES
    • , G. K. SKINNER
    •  & A. P. WILLMORE


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