A stellar combustor is a kind of bomb. They can be deployed in or near stars to cause massive explosions, potentially chain-reacting through other stars to cause incalculable destruction.
History and Use
These devices have, as far as anyone knows, only been used twice. Both times were attempts to destroy Rigour, and both failed[1].
The First Stellar Combustor
the first use of a Stellar Combustor was when those fleeing Rigour detonated the combustors behind them in an attempt to stop the divine from following. This was partially successful, as it propelled their people farther into the Milky Way Galaxy, though destroyed many galaxies in between. Rigour was however not stopped entirely, and generations later it would find its way to what had become the Autonomous Diaspora.
The Second Stellar Combustor
The second Stellar Combustor was detonated by the Autonomous Diaspora, this time in an attempt to destroy Rigour entirely. The bomb was delivered in a suicide mission by the crew of the Wayfarer True, a group of Old Earth cultists. The ensuing explosions killed hundreds of billions[2], destroying many populated worlds. This was ultimately only a temporary solution as rather than destroy Rigour, it was simply shot across the galaxy to the Golden Branch star system, where it remained dormant for centuries. Notably the divine Independence was present in the Diaspora at this time, and was a witness to effects of the combustor.