stars

Front: According to the ESRT, what is the life cycle path of a low-mass star similar to our Sun?

Back: Nebula -> Protostar -> Main Sequence Star -> Red Giant -> Planetary Nebula -> White Dwarf.

Front: What is the life cycle path of a high-mass star?

Back: Nebula -> Protostar -> Main Sequence Star -> Red Supergiant -> Supernova -> Neutron Star or Black Hole.

Front: What process powers main sequence stars, and what elements are primarily involved?

Back: Nuclear fusion, primarily converting hydrogen into helium in their cores.

Flashcard Set 2: Hertzsprung-Russell (HR) Diagram (NYS Earth Science)

Front: What two stellar properties are plotted on the axes of an HR Diagram (Refer to ESRT if needed)?

Back: The Y-axis plots Luminosity (or Absolute Magnitude) and the X-axis plots Surface Temperature (or Spectral Type/Color, which increases to the left).

Front: Where do most stars, including our Sun, spend the majority of their lives on the HR Diagram?

Back: On the Main Sequence, a diagonal band from the upper-left (hot, luminous) to the lower-right (cool, dim).

Front: Where are Red Giants and Supergiants located on the HR Diagram, and what does this tell us about them?

Back: In the upper-right section (cool surface temperature, very high luminosity). This indicates they are very large stars.

Front: Where are White Dwarfs located on the HR Diagram, and what does this tell us about them?

Back: In the lower-left section (hot surface temperature, very low luminosity). This indicates they are very small and dense.

Front: How can the HR Diagram help us understand stellar evolution?

Back: Stars move on the HR Diagram as they age. For example, a star moves from the Main Sequence to the Red Giant region as it expands and cools, and then to the White Dwarf region after shedding its outer layers.

Flashcard Set 3: Nucleosynthesis in Stars (NYS Earth Science)

Front: What is stellar nucleosynthesis?

Back: The process by which stars create new, heavier elements from lighter ones through nuclear fusion reactions in their cores.

Front: What elements are primarily formed during the main sequence phase of a star's life?

Back: Primarily helium from the fusion of hydrogen.

Front: As a star ages past the main sequence (e.g., into a Red Giant), what heavier elements can it begin to fuse?

Back: It can fuse helium into carbon and oxygen (the triple-alpha process).

Front: In very massive stars, fusion can continue to form elements up to what atomic number?

Back: Up to iron (Fe). Fusion into iron is the last energy-producing stage.

Front: Why can't stars produce energy by fusing elements heavier than iron?

Back: Fusing elements heavier than iron requires energy rather than releasing it. Iron has the most stable nucleus, so fusion beyond iron consumes energy, leading to the collapse of the star's core.

Front: How are elements heavier than iron (like gold, silver, and uranium) formed?

Back: They are primarily formed during the immense energy release of supernova explosions or from neutron star mergers through rapid neutron capture processes.