This illustration shows a young star undergoing a type of growth spurt. Left panel: Material from the dusty and gas-rich disk (orange) plus hot gas (blue) mildly flows onto the star, creating a hot spot. Middle panel: The outburst begins - the inner disk is heated, more material flows to the star, and the disk creeps inward. Right panel: The outburst is in full throttle, with the inner disk merging into the star and gas flowing outward (green). https://photojournal.jpl.nasa.gov/catalog/PIA22917