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Swift XRT image of X-ray light echoes around V404 Cyg
Credit: Andrew Beardmore (Univ. of Leicester) and NASA/Swift


Star of Wonder

Massive stars, when they run out of fuel and collapse, can leave behind extraordinary objects: black holes. Black holes are rents in the fabric of spacetime, producing regions that are completely cut off from the rest of our Universe. Black holes within our galaxy and elsewhere often reveal themselves by tell-tale X-ray emission, produced when the black hole swallows material from an unfortunate neighboring star. Black holes are both the simplest objects we know about, and the most mysterious and paradoxical. A particularly interesting example of these fascinating objects is the black hole in the system V404 Cygni, a binary star system that, after 26 years of quiescence, lit up the skies in 2015 with a large burst of X-ray emission. The Swift satellite almost immediately pointed at the system, and observed the fascinating image shown above. The circular rings surrounding V404 Cygni in the image above were produced by the X-rays from the outburst of V404 Cygni echoing off sheets of cosmic dust between us and the star. The large 2015 X-ray outburst, which lasted about 2 weeks, is believed to have been produced when the black hole in V404 Cygni swallowed an unusually large amout of matter ripped off its stellar companion. No one yet knows why the X-ray uproar occurred in 2015, or when or if it will happen again.
Published: December 26, 2016


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Each week the HEASARC brings you new, exciting and beautiful images from X-ray and Gamma ray astronomy. Check back each week and be sure to check out the HEAPOW archive!
Page Author: Dr. Michael F. Corcoran
Last modified Monday, 02-Jan-2017 10:31:51 EST