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Résumé : The Hayabusa2 sample-return capsule entered the atmosphere over South Australia on 5 December 2020 at 12 km/s. A slitless spectral video, taken from the ground with a hand-tracked consumer camera, shows the capsule alone from 80 to 49 km. In the first ten seconds of heating the shock layer emits the CN violet system, the CH A-X band and the C$_2$ Swan bands, the latter for the first time in remote observations of a capsule entry. C$_2$ ($T_{\rm rot}\approx9200$ K, $T_{\rm vib}\approx7800$ K) and CN (about 7000 K) are far hotter than the surface. C$_2$ and CH disappear while the heat flux is still rising and CN persists, which we relate to the early pyrolysis of the carbon-phenolic ablator and to the changing boundary-layer chemistry. The colour temperature of the heat shield rises from 2720 to 3080 K, in agreement with airborne results. The radiated energy is one to two orders of magnitude below that of natural fireballs, because the light comes from the hot surface rather than from ablation vapour. A faint persistent train lights up about 1 s after the passage and fades within a few seconds, probably chemiluminescence in the cooling wake.