Relativistic jet activity from the tidal disruption of a star by a massive black hole

Abstract

Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close^1,2, producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole^3,4,5,6,7. The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies^{8,9,10,11,12,13,14}, but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper^{<a id="ref-link-abstract-15" title="Zauderer, B. A. et al. The birth of a relativistic outflow in the unusual γ-ray transient Swift J164449.3+573451. Nature 10.1038/nature10366 (this issue)." href="/articles/nature10374#ref15" aria-label="Reference 15" data-track="click" data-track-action="reference anchor"...}