• Temperature Matters!
  • Core temp. doesn't get hot enough to fuse elements beyond carbon.
  • Think of it as an oven that can bake cookies (carbon) but not a cake (heavier elements).
• Running out of Fuel
  • When helium in the core is spent, the core starts shrinking while still emitting radiation.
  • It’s like a battery that's lost its juice but still has a small glow.
• Double Shell Action
  • Outside the core: a. Inner shell - Helium-fusing. (Helium's last hurrah!) b. Outer shell - Hydrogen-fusing. (H2’s farewell tour.)
  • Fun Fact: "Helium burning" & "Hydrogen burning" = Fusion, NOT actual fire🔥. No combustion here!
• Outer Layers’ Grand Exit
  • Outer layers drift away, creating a "planetary nebula".
  • Quick Note: This is NOT about planets. The term "planetary" is misleading, so don’t expect Jupiter 2.0!
• Tiny but Mighty Core
  • The core becomes small, roughly Earth-sized. It's filled with ions and free electron gas.
  • Imagine an egg yolk (core) shrinking inside a bigger egg!
• The Superpower of Electron Gas
  • The electron gas puts its foot down with "electron degeneracy pressure".
  • This pressure is thanks to the Pauli exclusion principle: Two electrons can't share the same room (quantum state). They need personal space!
  • No further shrinkage. The star gets a new title: 🌟White Dwarf🌟.
• The Long Cool-Down
  • Over billions of years, our white dwarf chills out.
  • Fun Density Fact: When the Sun becomes this dense, it'll be around 10⁹ kgm^-3. A cup of this stuff would weigh 1000 tonnes. Imagine trying to lift a cup of coffee that weighs as much as 200 elephants!

• Modelling: Creating virtual scenarios to study objects.
• Experiments: Actual tests, often hands-on.

Astronomy & astrophysics largely depend on models. Why? The universe is vast, and it’s not feasible to manually test everything. So

🤔Question Time: Is knowledge from models & simulations as golden as that from direct experiments?

🌍 Real-world Example: We can't experiment on actual stars, so we use models to predict and understand their behavior. It's like using a game simulation to practice before the real match!

Happy Stargazing! 🌟🔭 And remember, even in the vast universe, every tiny particle (like you) matters! ✨🌌