There lives an ancient tribe near Timbuktu, Mali in West Africa believed to be of Egyptian decent whose traditions speak of a star unseen to the human eye according to a discovery made by French anthropologists Marcel Griaule and Germain Dieterlen in the 1930’s. This star was not photographed till the 1970’s.
Dogon priests also spoke of a race of people called Nommos who visited Earth thousands of years ago. According to Dogon lore, the Nommos were amphibious looking beings who travelled from a planet from a third undiscovered star in the Sirius Star System called Emme Ya.
They apparently shared astronomical knowledge about their world as well as our own solar system. The fact that the Dogon have ancient artifacts used in ceremonies dating back nearly a thousand years makes it unlikely that the information was more recently leaked to them from the modern world.
You can also see signs of them in Babylonian, Accadian, and Sumerian myths.