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About the Poster

One of the most amazing things about gamma-ray bursts is their enormous power. Power is defined as the amount of energy emitted per unit time. Shown on the poster is a bar graph which compares the power emitted by several different radiant objects or events. The values given represent the peak power output of each. In other words, it is a snapshot in time at the instant each object or event is emitting the greatest amount of power it will ever emit. Some things - like the light bulb - emit constant power over time. Other things like a supernova explosion or a gamma-ray burst can emit enormous amounts of power one second and thousands or hundreds of thousands of times less power the next second. By showing peak power, we allow ourselves to compare very different things like light bulbs and supernovae in a meaningful way. Simply put, we display on our graph the following information: in the one second (whenever it occurred) that they each emitted their maximum power, what was it?

It may be interesting to consider the total power emitted as well. This takes into account the amount of time that each object or event emitted energy and how much energy they emitted as a function of time. Consider this, the total power emitted by a supernova is only about a factor of 10 less than that of a gamma-ray burst. What does this tell us about the amounts of time over which these events occur?

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Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.

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