Star Lifecycle, Light, and the Universe

Flashcards covering key vocabulary and concepts from the lecture notes.

Emission (Light)

Electron falls to lower energy level, emits a photon, and loses energy.

Absorption (Light)

Electron jumps to a higher energy level, absorbs a photon, and gains energy.

Spectra

Unique to each element, like fingerprints; can be emission or absorption types.

Nuclear Fusion (Stars)

Hydrogen nuclei fuse to form helium, converting mass into energy (E = mc²).

Main Sequence Star

Stars that fuse hydrogen into helium in their cores.

Giants (e.g., Red Giant)

Stars with expanded outer layers due to hydrogen shell fusion; low density, high volume.

Supergiants

Stars that fuse heavier elements in layers; hotter, larger, and less dense than Giants.

Supernova

The explosion of a star caused by the collapse and rebound after fusion of silicon to iron.

Redshift

The shift of light to longer wavelengths (redder colors) when a light source is moving away.

Blueshift

The shift of light to shorter wavelengths (bluer colors) when a light source is moving toward us.

White Dwarf

The core of a star that remains after it has cooled and ceased fusion; no fusion occurs.

Planetary Nebula

Glowing outer layers of a star ejected as it transitions to a white dwarf.

Big Bang Theory

The prevailing cosmological model for the universe, stating it began as an infinitely dense point and has been expanding ever since.

Cosmic Microwave Background Radiation (CMB)

Thermal radiation left over from the time of recombination in Big Bang cosmology.