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In this letter, we report the discovery of an intriguing HVS (J1443+1453)candidate that is probably from the Sagittarius Dwarf Spheroidal galaxy (SgrdSph). The star is an old and very metal-poor low-mass main-sequence turn-offstar (age $\sim14.0$ Gyr and [Fe/H] $= -2.23$ dex) and has a total velocity of$559.01^{+135.07}_{-87.40}$ km s$^{-1}$ in the Galactic rest-frame and aheliocentric distance of $2.90^{+0.72}_{-0.48}$ kpc. The velocity of J1443+1453is larger than the escape speed at its position, suggesting it a promising HVScandidate. By reconstructing its trajectory in the Galactic potential, we findthat the orbit of J1443+1453 intersects closely with that of the Sgr dSph$37.8^{+4.6}_{-6.0}$ Myr ago, when the latter has its latest pericentricpassage through the Milky Way. The encounter occurs at a distance$2.42^{+1.80}_{-0.77}$ kpc from the centre of Sgr dSph, smaller than the sizeof the Sgr dSph. Chemical properties of this star are also consistent withthose of one Sgr dSph associated globular cluster or of the Sgr stream memberstars. Our finding suggests that J1443+1453 is an HVS either tidally strippedfrom the Sgr dSph or ejected from the Sgr dSph by the gravitational slingshoteffect, requiring a (central) massive/intermediate-mass black hole or a(central) massive primordial black hole in the Sgr dSph.

Discovery of A candidate Hypervelocity star originated from the Sagittarius Dwarf Spheroidal galaxy