Consider the magnetar.

https://en.wikipedia.org/wiki/Magnetar

"A magnetar's 10^10 tesla field, by contrast, has an energy density of 4.0×1025 J/m3, with an E/c2 mass density more than 10,000 times that of lead."

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1970-01-01 7 hours ago | parent [-]

Yes, magnetars are considerably more rare than black holes and considerably more interesting to study in terms of raw horsepower. Imagine a type-2 civilization using them as engines or launchers for spacecraft to zip around the galaxy.

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ck2 7 hours ago | parent [-]

the radiation from a magnetar exceeds any other star, overcoming that would seem implausible

still trying to wrap my mind around kilonovas (colliding neutron stars)

ie. they can pop out earth-sized chunks of gold, in theory, and since they aren't black holes that would be VISIBLE, albeit also "in theory" lol

* https://www.nasa.gov/image-article/unfolding-story-of-kilono...

maybe Roman can spot one someday, that would be something

	▲	pfdietz 3 hours ago \| parent [-]
		> they can pop out earth-sized chunks of gold The can produce Earth masses of gold, but of course not in the form of "chunks". The gold starts as atoms in a highly ionized gas and only much later cools enough to form solids (dust).