Aragorn was known as the 'Eagle of the Star' by his fellow soldiers in Gondor, because he was as swift and sharp-eyed as an Eagle, and bore the Star of the Dúnedain on his cloak. Decades later, Aragorn would bear the Elessar in a brooch shaped like an Eagle, given as a gift from Galadriel. This seems to be simple coincidence, though perhaps the Men of Gondor were being unwittingly prophetic when they chose this name for Aragorn, or possibly Galadriel had heard of his exploits in Gondor and chose the brooch accordingly.