Illustrations of Light Echo
Quicktime
MPEG
This sequence of illustrations shows how an outburst from Sgr A* -- produced when material falls into the black hole -- generates a light echo. The faint, star-like object in the center represents the typical, quiet behavior, when the black hole does not have much material to consume. When the black hole's feeding rate increases dramatically, the material around Sgr A* brightens. Although the black hole outburst stops, the light from the outburst continues to travel outwards and then reflects, or echoes, off three clouds of gas in its path.
[Runtime: 0:13]
(Credit: NASA/CXC/M.Weiss)