Disk-mediated accretion burst in a high-mass young stellar object

Solar-mass stars form via disk-mediated accretion. Recent findings indicate that this process is probably episodic in the form of accretion bursts1, possibly caused by disk fragmentation2, 3, 4. Although it cannot be ruled out that high-mass young stellar objects arise from the coalescence of their low-mass brethren5, the latest results suggest that they more likely form via disks6, 7, 8, 9. It follows that disk-mediated accretion bursts should occur10, 11. Here we report on the discovery of the first disk-mediated accretion burst from a roughly twenty-solar-mass high-mass young stellar object12. Our near-infrared images show the brightening of the central source and its outflow cavities. Near-infrared spectroscopy reveals emission lines typical for accretion bursts in low-mass protostars, but orders of magnitude more luminous. Moreover, the released energy and the inferred mass-accretion rate are also orders of magnitude larger. Our results identify disk-accretion as the common mechanism of star formation across the entire stellar mass spectrum.