The Dogon are an ethnic group living in the central plateau region of Mali, in Western Africa, south of the Niger bend, near the city of Bandiagara, in the Mopti region. The population numbers between 400,000 and 800,000.
The Dogon are believed to be of Egyptian decent and their astronomical lore goes back thousands of years to 3200 BC. According to their traditions, the star Sirius has a companion star which is invisible to the human eye. This companion star has a 50 year elliptical orbit around the visible Sirius and is extremely heavy. It also rotates on its axis.
The astronomical information known by the Dogon was not discovered and verified until the 19th and 20th centuries. Their oral traditions say this knowledge was given to them by the Nommo. The source of their information may date back to the time of the ancient Egyptian priests.
in the late 1930s, four Dogon priests shared their most important secret tradition with two French anthropologists, Marcel Griaule and Germain Dieterlen after they had spent an apprenticeship of fifteen years living with the tribe. These were secret myths about the star Sirius, which is 8.6 light years from the Earth.
The Dogon priests said that Sirius had a companion star that was invisible to the human eye. They also stated that the star moved in a 50‑ year elliptical orbit around Sirius, that it was small and incredibly heavy, and that it rotated on its axis.
Initially the anthropologists wrote it off, because they didn't appreciate the astronomical importance of the information.
What they didn't know was that since 1844, astronomers had suspected that Sirius A had a companion star. This was in part determined when it was observed that the path of the star wobbled.
In 1862 Alvan Clark discovered the second star making Sirius a binary star system (two stars). In the 1920's it was determined that Sirius B, the companion of Sirius, was a white dwarf star. White dwarfs are small, dense stars that burn dimly. The pull of its gravity causes Sirius' wavy movement. Sirius B is smaller than planet Earth, confirming Dogon folklore.