VY Canis Majoris (VY CMa, HIP 35793) is a red Supergiant star located in Canis Canis major, about 45-6450 light years away from the Earth, and its age is estimated to be close to NGC 2362, so it is 3-4 million years old. Its apparent magnitude is 7.96~5. 1 1. Probably. Its mass is about 35-50 times that of the sun, and its radius is about 1800-2 100 times that of the sun (some people say that its diameter is 1420 times that of the sun, which is wrong). If Vi Canis placed in the position of the sun, its edge will exceed Saturn's orbit. The Vi Canis major is not only huge, but also 500,000 times brighter than the sun. It is different from other special Supergiant star, and it mostly appears in conjoined or multi-satellite systems, because it is a single satellite, and its mass loss rate is extremely fast. Dog VY is also a semi-regular variable star, and its dimming period is about 2000 days. The average density is 5 ~ 30mg/m3. Although its volume is about 1000 billion times that of the sun, its mass is only about 40 times that of the sun (vy is the largest star and the heaviest star is R 136a 1).