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HDE 226868
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HDE 226868

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The Information Architects of Encyclopaedia Britannica

Learn about this topic in these articles:

  • Cygnus X-1
    Cygnus X-1

    The primary star, HDE 226868, is a hot supergiant revolving about an unseen companion with a period of 5.6 days. Analysis of the binary orbit shows that the companion has a mass of 21 solar masses. A star of that mass should have a detectable spectrum, but the…

    Read More

    The primary star, HDE 226868, is a hot supergiant revolving about an unseen companion with a period of 5.6 days. Analysis of the binary orbit shows that the companion has a mass of 21 solar masses. A star of that mass should have a detectable spectrum, but the…

    Read More