Did the Ancient Egyptians Record the Period of the Eclipsing Binary Algol—The Raging One?

  title={Did the Ancient Egyptians Record the Period of the Eclipsing Binary Algol—The Raging One?},
  author={Lauri Jetsu and Sebastian Porceddu and Joonas Lyytinen and Perttu Kajatkari and Jyri J. Lehtinen and Tapio Markkanen and Jaana Toivari-Viitala},
  journal={The Astrophysical Journal},
The eclipses in binary stars give precise information of orbital period changes. Goodricke discovered the 2.867 day period in the eclipses of Algol in the year 1783. The irregular orbital period changes of this longest known eclipsing binary continue to puzzle astronomers. The mass transfer between the two members of this binary should cause a long-term increase of the orbital period, but observations over two centuries have not confirmed this effect. Here, we present evidence indicating that… Expand
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