WEBVTT FILE 1 00:00:00.000 --> 00:00:12.637 ON-SCREEN: Two stars orbit each other inside the U Monocerotis system, a binary system with a large disk of dust and debris. 2 00:00:12.637 --> 00:00:19.978 When one of the stars passes behind the disk from the Earth's perspective, it dims noticeably.