As hinted at in the title, assuming the technology/means existed that could absorb energy fast enough, would it be possible to stop a star from going supernova, effectively “calming” it?
This is for a novel (not exactly a sci-fi one) but I’d like to keep in the realms of “technically possible”.
In short, no.
Precenting a supernova would require halting the gravitational collapse of the star as it runs out of fuel. This means either feeding the star faster than it can burn (our sun is too small to nova and still burns through 600 million tons of hydrogen per second), or removing the iron, silicon and other metals from the core of the star faster than they can build up (slightly fewer hundreds of millions of tons per second).
You’re going to need some very unrealistic scifi to accomplish either of those. Either some mechanism for pulling gigatons per second from the bottom of the star’s gravity well, a plentiful supply of gas giant planets you can drop into it, or both.