  The coronae in X-ray binaries (XRBs) still remain poorly understood, although
they have been believed for a long time to play a key role in modeling the
characteristic outbursts of XRBs. Type-I X-ray bursts, the thermonuclear
flashes happening on the surface of a neutron star (NS), can be used as a probe
to the innermost region of a NS XRB, where the corona is believed to be located
very close to the NS. We report the discovery of a tiny life cycle of the
corona that is promptly co-evolved with the type-I bursts superimposed on the
outburst of the NS XRB IGR J17473$-$2721. This finding may serve as the first
evidence of directly seeing the rapid disappearance and formation of a corona
in an XRB with a cooling/heating timescale of less than a second, which can
strongly constrain the accretion models in XRBs at work.
