wizardingfashion:

A beautiful, traditional cloak once worn by famed astronomer Perpetua Fancourt. Fancourt, the inventor of the lunascope (an instrument now indispensable to astronomers) was highly intelligent and, as a graduate of Hogwarts School of Witchcraft and Wizardry, a former Ravenclaw.

Fancourt once stated in an interview on the Wizarding Wireless Network that this cloak was a gift of her grandmother and she always wore it while studying the sky, because it was warm and the embroidered stars on the cloak were Charmed to twinkle softly when the constellation Lyra was overhead.