“Now when the first Vingilot was set to sail in the seas of heaven, it rose unlooked for, glittering and bright; and the people of Middle-earth beheld it from afar and wondered, and they took it for a sign, and called it Gil-Estel, the Star of High Hope. And when this new star was seen at evening, Maedhros spoke to Maglor his brother, and he said: 'Surely that is a Silmaril that shines not in the West?' And Maglor answered: 'If it be truly the Silmaril which we saw cast into the sea that rises again by the power of the Valar, then let us be glad: for its glory is seen now by many, and yet secure from all evil.' Then the Elves looked up, and despaired no longer; but Morgoth was filled with doubt.”
Book:The Silmarillion