Sirius A and B are both very mature stars, despite their age's being only 242 and 228 million years respectively. They are both charismatic, and they both make excellent leaders. They both like to joke around a lot, especially B! They are both hotter than the Sun, although only A is more massive, more luminous, and bigger in diameter. Sirius B is a white dwarf, being about the same size as Earth, but just as massive as the Sun. Both are binary stars, and they take 50 years to orbit each other.