There are many stars in the universe, and each one has a different lifespan. The star with the shortest lifespan is the red dwarf. Red dwarfs are small, cool stars that burn slowly and steadily. They are very common in the universe, and make up about three-quarters of all stars. However, their small size means they have a very short lifespan â€“ only a few billion years. In contrast, our Sun is a middle-aged star with an expected lifetime of 10 billion years. So while red dwarfs may be common, they donâ€™t last long enough to see much change in the universe around them.