Hypergiant
From Memory Alpha, the free Star Trek reference.
The rare hypergiant star is one which shares similar characteristics with a supergiant star, but is 100 times more massive than Sol. The theoretical lifespan of a hypergiant is one to two million years. Supposedly, like its supergiant companions, a hypergiant star will go supernova when it exhausts its supply of fuel and gravity crushes the inert remains.
The starship Enterprise was the first Earth ship to research a red hypergiant at close range in 2152; it was nearly a billion kilometers in circumference and was not expected to go supernova for another one hundred or two hundred years. (ENT: "Cogenitor")
