What is qpo?

QPO, or Quasi-Periodic Oscillation, is a phenomenon observed in astrophysical systems such as neutron stars, black holes, and white dwarfs. It is characterized by repeating variations in the intensity of radiation emitted by these objects, with a period ranging from a few seconds to a few hundred seconds. QPOs are believed to be caused by oscillations of the accretion disk of material surrounding a compact object, or by variations in the magnetic field of the object itself. Studying QPOs can provide valuable insights into the properties of these astrophysical systems, such as their mass and spin rate, and can help us understand the fundamental physics of gravity and radiation in extreme environments.