How bright will Sirius be when it's closest to the solar system? Preferably in terms of percentage. As a layman, visual apparent magnitude means little to me.
From Sirius: Brightest Diamond in the Night Sky by Jay B. Holberg we have current distance of Sirius ~8.5ly, closest approach will be ~6.7ly. The intensity of of light from Sirius assuming constant luminosity scales as distance squared, so the intensity (power per unit area at the eye) at closest approach will be: $\left(8.5/6.7 \right)^2 \approx 1.6$ times that today, which is a change of magnitude from about $-1.4$ to about $ -1.6$