What do you know today that you didn't know yesterday?

[Anomalocaris]

It is said a supernova can be brighter than an entire galaxy, and is thus the brightest common object in the known universe.

However, it is expected that in the near future, technology would be available to construct a laser which would actually be brighter than a supernova, in the sense it would put out more power in xray than a supernova puts out across all electromagnetic spectrum,  but only for something like one quintillionth (million trillion) of a second.  Of course the total energy the laser can emit is still infinitesimally small next to what the entire supernova event emits over its life.    

But for one million-trillionth of a second, the wits and craft of man can literally outshine anything else in all of the entire known universe.

That’s still something.

I’m not sure massive output in x-ray wavelengths would qualify as ‘brightness’.

Boru

in astronomy any electromagnetic energy emitted counts as brightness.