Supergiant Stars

If our Sun is an average sized star, there are some true monsters out there. They're the supergiant stars, and they come in two flavors: red and blue. The supergiants are the most massive stars out there, ranging between 10 to 70 solar masses, and can range in brightness from 30,000 to hundreds of thousands of times the output of the Sun. Unlike a relatively stable star like the Sun, supergiants are consuming hydrogen fuel at an enormous rate and will consume all the fuel in their cores within just a few million years down to just a few hundred thousand years. Supergiant stars live fast and die young, detonating as supernova; completely disintegrating themselves in the process. Supernova explosions can be brighter than an entire galaxy, and can be seen from very far away.
First, let's take a look at a red supergiant star. These are stars with many times the mass of the Sun, and one of the best known examples is Betelgeuse, in the constellation of Orion. Betelgeuse has 20 times the mass of the Sun, and puts out about 135,000 times as much energy as the Sun. It's one of the few stars that have ever had their disk imaged; astronomers estimate that it's 1,000 times the radius of the Sun. With that size, Betelgeuse would engulf the orbits of Mars and Jupiter in our Solar System. Astronomers guess that Betelgeuse is only 8.5 million years old, and they expect that it will detonate as a supernova within the next 1000 years or so. When it does finally go off, the supernova explosion will be as bright as the Moon in the night sky. Another example of a red supergiant is the star Antares.
Blue supergiants are much hotter than their red counterparts. A good example of a blue supergiant is Rigel, also in the Orion constellation. Rigel has a 17 times the mass of the Sun, and 66,000 times the luminosity of the Sun – it's the most luminous star in the neighborhood. It's not as large as a red supergiant, with only 62 times the radius of the Sun.