  We measure and model the combined relaxation of a qubit coupled to a discrete
two-level system~(TLS) environment, also known as the central spin model. If
the TLSs are much longer-lived than the qubit, non-exponential relaxation and
non-Poissonian quantum jumps can be observed. In the limit of large numbers of
TLSs, the relaxation is likely to follow a power law, which we confirm with
measurements on a superconducting fluxonium qubit. Moreover, the observed
relaxation and quantum jump statistics are described by the Solomon equations,
for which we present a derivation starting from the general Lindblad equation
for an arbitrary number of TLSs. We also show how to reproduce the
non-Poissonian quantum jump statistics using a diffusive stochastic
Schr\"odinger equation. The fact that the measured quantum jump statistics can
be reproduced by the Solomon equations, which ignore the quantum measurement
backaction, hints at a quantum-to-classical transition.
