Often, we call the stages of a star its “life cycle”, and I’ve been thinking about this for a bit.
Stars meet many of the requirements for living organisms: they can consume matter, they can react to stimuli (sort of, does gravity count? e.g. binary systems), they can reproduce (they expel gas clouds on death that can eventually create new stars), they can grow and change size over their lifespan, and they maintain equilibrium (between gravity and radiation pressure from fusion)
What stops stars from being considered living objects?
But why does it have to be unobservable? And if it is unobservable, how do you know that it is there?
We know pretty well and can observe that children inherit the DNA of their parents. And nowadays we also know that it is not only the DNA, but the epigenetic postprocessing that gets (at least partially) inherited. So according to your definition if we ever fully understood how bacteria propagate and behave, it would not be alive anymore?