If every hydrogen atom instantly vanished for a few seconds, what is the immediate consequence for a star's energy output?

Answer

The fusion reaction stops instantly

If the fuel source vanishes, the fusion reaction stops instantly, and the primary source of electromagnetic radiation would cease the moment the hydrogen atoms disappeared.

If every hydrogen atom instantly vanished for a few seconds, what is the immediate consequence for a star's energy output?
Elementuniversehydrogencosmologyabsence