Star Formation
Nuclear Fusion
Red Giants
Ending Stages
HR Diagram
100

What is a newborn star called before it begins to create visible light?

a protostar

100

Nuclear fusion mainly occurs in the ______ of a star.

core

100

The _____ of stars determine how they will evolve.

masses

100

Is a white dwarf is the ending stage of an average or massive star?

average

100

The HR diagram stands for the ______ _______ diagram.

a) Haribo-Roots

b) Hertzsprung-Russell

c) Haligat-Rousso

d) Heliocentric-Regolith

b) Hertzsprung-Russell

200

Stars form from _______.

dark nebula/molecular cloud

200

When a star begins nuclear fusion, what can it be classified as?

a main-sequence star

200

Nuclear fusion produces _______, which generates internal pressure pushing outwards.

energy

200

True or false: a supernova occurs as the core of a star shrinks and becomes denser/hotter rapidly as it collapses. This releases a huge amount of energy that create shock waves, causing the star's outer layers to explode.

true

200

The HR diagram is a graph measured by a star's _____ and ______.

temperature, luminosity

300
Name one way a dark nebula can become unstable.

gravity of a nearby star, disruption from supernova/galactic collision/cloud collision

300

In nuclear fusion, 2 hydrogen atoms fuse to become ________.

helium

300

Are red giants generally hotter or cooler than bluer/younger stars?

cooler

300

A white dwarf is found at the core of a ________.

a) diffuse nebula

b) reflection nebula

c) planetary nebula

d) dark nebula

c) planetary nebula

300

The brightest stars are at the ___ of the HR diagram.

top

400
What happens after a dark nebula becomes unstable?

It begins to collapse and cloud fragments form

400
True or false: when a star begins nuclear fusion, it is in a stable phase since the liquid core pushing inwards is equal to the gravity pushing outwards.

false

400

Why do red giants expand?

Fuel change, the star is fusing heavier elements in the red giant phase, so expands due to more energy being produced inside the star's core
400

A supernova can generate either a _______ or a ________ as the ending stages of the star.

black hole, neutron star

400

A star has 10 times the luminosity of the Sun and has a temperature of 8,000 K. What evolutionary stage is this star in?

main sequence

500

What is one difference between protostars and pre-main-sequence stars?

protostars are not visible (not producing optical light), collapse quickly, less dense, more unstable, occurs before PMS phase

500

When a star begins nuclear fusion, it is in a stable phase known as _________ __________.

hydrostatic equilibrium

500
Why are red giants red?
The star expands when transitioning from the main sequence to the red giant phase. The energy coming outwards is less concentrated since there is a larger surface area, which causes a redder color to reach the observer
500

What are neutron stars composed of? How does this occur?

Neutrons. After a supernova, the star's core is crushed together by gravity, forcing electrons to fuse with protons and create neutrons. This results in a star that's mostly made up of neutrons

500

A star has a spectral class of G0 and an absolute magnitude of -9. What evolutionary stage is this star in?

supergiant

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