Original: Its brightness at these rare near-perihelion oppositions makes Bamberga the brightest C-type asteroid, roughly one magnitude brighter than 10 Hygiea's maximum brightness of around +9.1.
Simplified: Its brightness at these rare near-perihelion oppositions makes Bamberga the brightest C-type asteroid, about one magnitude brighter than 10 Hygiea's maximum brightness of around +9.1.