Hannah looked at the instument to professor was referring to and a couple of things went through her mind. She wasn't sure if she knew the technical term, but she decided to give it a go anyways. With her hand raised she said "Professor I think that is a Nocturnal instrument and it tells time with the help of certain stars." She wasn't sure if nocturnal was the right word for it, but she was sure that the professor would know what she was talking about at any rate.