Current Location:
* The Sun is currently a main sequence star located on the lower main sequence of the H-R diagram. This means it's relatively cool (surface temperature around 5,500°C) and has a moderate luminosity.
Red Giant Phase:
1. Movement Upwards: As the Sun runs out of hydrogen fuel in its core, it will start fusing hydrogen in a shell surrounding the core. This will cause the Sun to expand dramatically, becoming a red giant.
2. Movement to the Right: The Sun's expansion will cause its surface temperature to decrease, making it cooler. This will shift the Sun's location on the H-R diagram to the right, towards cooler temperatures.
3. Increased Luminosity: The Sun will also become significantly brighter. Since it's now burning a larger amount of fuel, its total energy output will increase, moving the Sun upwards on the H-R diagram.
Overall Change:
The Sun's location on the H-R diagram will move from the lower main sequence to the upper right corner, signifying a cooler, larger, and much brighter star.
Key Takeaways:
* Red giants are cooler and larger than main sequence stars.
* Red giants are more luminous than main sequence stars.
* The H-R diagram helps visualize the evolution of stars, showing how their properties change over time.
