Heh. More like models about how far along it is with fusing each element in its core for fuel.
See, all stars begin life as main-sequence stars, like the Sun, fusing hydrogen into helium in their cores. The difference lies in how massive they are. The more massive a star, the quicker it burns through its hydrogen supply. Our sun is 5 billion years old, and has burned through half its core's supply of hydrogen. Betelgeuse, being 10 times as massive as the sun, fused all the hydrogen in its core into helium in a "mere" 10 million years. This has to do with the fact that throughout a star's life, it's caught in a delicate balancing act between gravity and heat. Heat released from the fusion reactions in the core threatens to cause the star to dissipate, while the star's own gravity threatens to make the star completely collapse. However, as long as the two forces balance each other out, the star remains happy and healthy. Thus, more massive stars, having stronger gravity, need to burn through their fuel faster in order to keep their cores hot enough to maintain balance.
Now, when a star finishes fusing hydrogen into helium, its core starts to collapse, getting denser and denser, and hotter and hotter. Eventually, the star's core becomes hot enough that it can start fusing helium into carbon... with some odd bits of oxygen and neon also getting created. But helium requires higher temperatures to fuse, and puts out less energy than hydrogen, so a star burns through its core's helium supply in only 10% of the time it took to burn hydrogen - 1 billion years for a star like the sun when it eventually becomes a red giant, 1 million years for Betelgeuse.
Now, in a star like the sun, temperatures and pressures never reach high enough levels to burn carbon, but in a more massive star like Betelgeuse, they do. Carbon is fused, producing mostly oxygen, neon, sodium, and magnesium, with some hydrogen and helium being released as side-products. It only takes a star about a thousand years to burn through its supply of carbon.
After carbon, neon is used as fuel. It takes the star only a few years to burn up its neon. Then comes oxygen. The star mainly produces silicon as the product of oxygen-burning, and the star will burn through its supply of oxygen in only 5 years. After that, it will have one final desperate attempt to stay alive, and fuse silicon into iron. Silicon-fusion is finished after only 24 hours. Once silicon fusion is done, the star will attempt to fuse iron... but there's a problem. Iron fusion puts out less energy than it takes to initiate, so now, the star can no longer maintain balance, and so collapses in on itself at nearly the speed of light. However, this much matter falling in at this high a speed causes shockwaves to form, which cause a rebound effect... and the rebound blasts the entire star apart in a supernova explosion. In a supernova, the temperatures become high enough for iron fusion to occur, in these explosions, all elements heavier than iron are formed.
Now, the models I mentioned suggest that Betelgeuse is just finishing up - if not completely finished - carbon-fusion. Or at least, it finished carbon-fusion 600 years ago, since it's 600 light-years away, and the light has taken 600 years to reach us. If this is true, then we have only about a decade before we see Betelgeuse go supernova. And when it does, it will be bright enough to see in the daytime sky. Luckily, Earth is far enough away to not have to deal with the immense radiation put out by the supernova.