rho Cas
Rho CasRho Cas (type semiregular) is a hypergiant star and one of the most luminous stars in our galaxy. Eruptions on these very rare, very massive stars produce huge mass ejections evidenced by dramatic spectral changes and optical dimming (an ejection in 2000 amounted to 10,000 Earths worth of material and caused a ~1.5-magnitude drop in visual brightness). |