Question

consider a main - sequence star that starts to burn hydrogen at a slightly slower rate. classify each stellar property according to whether it initially increases, decreases, or remains unchanged after the decrease in the hydrogen burning rate. decreases increases no change answer bank core temperature amount of heavy elements luminosity core size

Explanation:

• Core temperature: When hydrogen - burning rate decreases, less energy is generated in the core, so core temperature decreases as there is less nuclear fusion heat production.
• Amount of heavy elements: The rate of hydrogen - burning does not immediately affect the amount of heavy elements. Heavy elements are produced over long - term nuclear processes like helium - burning and beyond, and a short - term change in hydrogen - burning rate has no impact on their quantity.
• Luminosity: Luminosity is related to the energy output of the star. With a lower hydrogen - burning rate, less energy is produced, so luminosity decreases.
• Core size: A decrease in hydrogen - burning rate means less radiation pressure pushing outwards. The gravitational force starts to compress the core more, so the core size decreases.

Answer:

Decreases: core temperature, luminosity, core size
Increases: None
No change: amount of heavy elements