TESS observations reveal sustained quasi-periodic oscillations in multiple blazars

Quasi-periodic oscillations (QPOs) are a rare phenomenon in active galactic nuclei. They have been observed to occur at periods ranging from minutes to hours, days, weeks, and even years across the electromagnetic spectrum. A new study by Ashutosh Tripathi from the Xinjiang Astronomical Observatory of the Chinese Academy of Sciences, together with his collaborators, has identified highly significant short-timescale QPOs in several blazars.