Milky Way Galaxy Overview

These flashcards cover key concepts about the Milky Way Galaxy, its components, star formation processes, and the evidence for black holes.

What are the main components of the Milky Way Galaxy?

The Milky Way Galaxy consists of a disk, bulge, halo, and globular clusters.

What is the significance of supernova remnants?

Supernova remnants reveal newly made heavy elements and cool to emit visible light.

What defines a black hole?

A black hole is an object whose gravity is so powerful that not even light can escape it.

What evidence suggests the existence of a black hole at the center of our galaxy?

Stars appear to be orbiting something massive but invisible, indicating a black hole of ~4 million M☉.

What happens to gas from dying stars in the Milky Way?

Gas from dying stars mixes new elements into the interstellar medium and can eventually form new stars.

What is the star-gas-star cycle?

It is the process of gas from old stars recycling into new star systems.

What are planetary nebulae?

Planetary nebulae are formed when dying stars expel their outer layers.

How do stars in the disk of the Milky Way orbit?

Stars in the disk orbit in the same direction with little up-and-down motion.

What do molecular clouds in the Milky Way primarily consist of?

Molecular clouds are mostly composed of H2, with about 28% He and about 1% CO.

How does star formation occur in molecular clouds?

Gravity forms stars out of gas in molecular clouds, which complete the star-gas-star cycle.