How close are we to photographing Sgr A*'s ghost images?

Flares spiraling near Sgr A* produce faint "secondary" images — light bent almost all the way around the black hole before reaching us. Simulating future GRAVITY telescope observations, the authors find that collecting ten times more flare data alone isn't enough; you also need astrometric precision roughly 2.5 times better than today's. Hit both targets simultaneously and the secondary image signature becomes statistically unmistakable — a critical stepping stone toward imaging the photon ring itself.