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The Hakucho [CORSA-B] Satellite

image of Hakucho
Credit: NASA

Corsa-B was the first X-ray astronomy Japanese satellite. Launched on 21 February 1979, it was renamed Hakucho (Japanese for swan) symbolizing one of the most interesting X-ray objects, Cyg X-1. As many other X-ray satellite launched in that period, Hakucho was designed to study and monitor transient phenomena with particular emphasis on X-ray bursts. It was still operating when the second X-ray Japanese satellite Tenma launched in 1983.

Mission Characteristics

* Lifetime: 21 February 1979 - 16 April 1985
* Energy Range: 0.1 - 100 keV
* Payload:
  • Very Soft X-ray (VSX) experiment 0.1-0.2 keV
    Four units of proportional counters
    each with eff area ~ 78 cm2
    Two parallel to the spin axis FOV = 6.3° X 2.9° FWHM
    two offset FOV = 24.9° X 2.9° FWHM
  • Soft X-ray (SFX) 1.5-30 keV Six units of proportional counters
    Parallel to the spin axis :
    • Two FOV 17.6 deg FWHM; eff area=69 cm2 each
    • Two FOV 5.8 deg FWHM; eff area=40&83 cm2
    Two offset FOV = 50.3° X 1.7° FWHM eff area =32 cm2 each
  • Hard X-ray (HDX) 10-100 keV scintillator
    FOV 4.4° X 10.0° FWHM eff area =45 cm2
* Science Highlights:
  • Discovery of soft X-ray transient Cen X-4 and Apl X-1
  • Discovery of many burst sources
  • Long-term monitoring of X-ray pulsar (e.g. Vela X-1)
  • Discovery of 2 Hz variability in the Rapid Burster later named Quasi Period Oscillation.
* Archive: No data available at HEASARC
[About Hakucho] ( [Gallery] ( [Publications] (

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