Circumstellar dust refers to dust particles that surround and orbit a star within its circumstellar disk. This dust plays a crucial role in the formation of planetary systems, as it can coalesce and aggregate to form larger bodies such as asteroids, comets, and planets. Studying circumstellar dust can provide valuable insights into the early stages of planetary formation and the composition of planetary systems. Researchers use a variety of techniques, such as infrared spectroscopy and imaging, to study the properties and distribution of circumstellar dust around different types of stars.