6. Explain why Deneb will have a shorter lifespan than the Sun. __

Deneb has a much shorter lifespan than the Sun because it burns through its nuclear fuel at a dramatically faster rate. While the Sun is a relatively small, yellow star, Deneb is a blue-white supergiant, meaning it is much more massive and significantly hotter.Here's a breakdown:* **Mass:** Deneb's mass is estimated to be about 20 times greater than the Sun's. This greater mass leads to much higher core temperatures and pressures.* **Core Temperature and Pressure:** The higher core temperature and pressure in Deneb cause nuclear fusion reactions to occur at an exponentially faster rate than in the Sun. It's like a bonfire compared to a candle flame – the bonfire burns much brighter and hotter, but also consumes its fuel much more quickly.* **Fuel Consumption:** While Deneb has more fuel to start with, the rate at which it consumes that fuel drastically shortens its overall lifespan. The Sun, being smaller and cooler, burns its fuel much more slowly and will live for billions of years. Deneb, on the other hand, is expected to live only a few million years.In summary, although larger stars like Deneb start with more hydrogen fuel, their higher mass leads to a much faster rate of nuclear fusion, causing them to exhaust their fuel and reach the end of their lives much sooner than smaller, less massive stars like the Sun.