  The unluckiest star orbits a supermassive black hole elliptically. Every time
it reaches the pericenter, it shallowly enters the tidal radius and gets
partially tidal disrupted, producing a series of flares. Confirmation of a
repeated partial tidal disruption event (pTDE) requires not only evidence to
rule out other types of transients, but also proof that only one star is
involved, as TDEs from multiple stars can also produce similar flares. In this
letter, we report the discovery of a repeated pTDE, AT 2022dbl. In a quiescent
galaxy at $z=0.0284$, two separate optical/UV flares have been observed in 2022
and 2024, with no bright X-ray, radio or mid-infrared counterparts. Compared to
the first flare, the second flare has a similar blackbody temperature of
~26,000 K, slightly lower peak luminosity, and slower rise and fall phases.
Compared to the ZTF TDEs, their blackbody parameters and light curve shapes are
all similar. The spectra taken during the second flare show a steeper continuum
than the late-time spectra of the previous flare, consistent with a newly risen
flare. More importantly, the possibility of two independent TDEs can be largely
ruled out because the optical spectra taken around the peak of the two flares
exhibit highly similar broad Balmer, N III and possible He II emission lines,
especially the extreme ~4100{\AA} emission lines. This represents the first
robust spectroscopic evidence for a repeated pTDE, which can soon be verified
by observing the third flare, given its short orbital period.
