  Recently, Vagnozzi and Visinelli's work [Phys. Rev. D 100, 024020 (2020)]
reveals that M87*'s shadow establishes an upper limit of $l \lesssim 170$ AU,
where $l$ is the AdS$_5$ curvature radius and 1 AU is one astronomical unit.
The Event Horizon Telescope, on the other hand, just captured the first image
of the shadow of Sagittarius A* (SgrA*), the Galactic center source associated
with a supermassive black hole. In this paper, we are motivated to
comprehensively explore a new upper limit of $l$ with the shadow of SgrA*, and
the findings suggest that $l \lesssim 0.097$ AU. Our results improve accuracy
by three orders of magnitude. This is also one of the first quantifiable
limitations on exotic physics derived from the remarkable first image of the
shadow of SgrA*.
