Quiz 3a: Stars and the HR diagram

Vocabulary terms regarding stellar evolution, core collapse thresholds, and features of the Hertzsprung-Russell (HR) diagram based on the lecture quiz.

HR diagram vertical axis

The vertical axis of the HR diagram measures luminosity or absolute magnitude.

HR diagram horizontal axis

The horizontal axis of the HR diagram measures temperature, color, or spectral class.

Red giant

A star located in the upper right of the HR diagram; the position where the sun will move after its core runs out of hydrogen.

Blue giant

A star located in the upper left of the HR diagram.

White dwarf

The object produced when a star's core collapses if its mass is less than $1.4$ solar masses; located in the lower left of the HR diagram.

Red dwarf

Main sequence stars located in the lower right of the HR diagram that stay on the main sequence the longest.

Main sequence

The region of the HR diagram extending from the upper left to the lower right.

The sun

A star located near the middle of the HR diagram.

Iron

The element produced at the end of a massive star's fusion process, after which no more energy can be obtained by nuclear fusion.

Planetary nebula

An object, often with a ring-like shape, formed when the outer envelope of a star drifts away as its core collapses into a white dwarf.

Neutron star

The object produced when a star's core collapses if its mass is between $1.4$ and $3$ solar masses.

Pulsar

A neutron star that is rapidly rotating.

Black hole

The object produced when a star's core collapses if its mass is greater than $3$ solar masses.