A theory that the universe began as a small singularity and then inflated and got bigger/expanded.

Self-luminous; a mass of gas and dust held together by its own gravity; energy comes from internal nuclear fusion.

The massive explosion of dying star

Where stars are born.

A system of millions or billions of stars. Held together by gravity.

A central star with its associate planets, moons, asteroids, etc. Everything orbits the central star.

These orbit planets.

A place in space where the gravity is so strong that nothing can escape it.

Is the sun considered a high mass star or a low mass star?

Stars are self-luminous. Self-luminous means:

Nebula are called stellar nurseries because:

A star's color helps us figure out its:

After a star runs out of fuel, (whether it is high mass or low mass), it then turns into:

The last stage of a low/medium mass star

High mass (massive) stars end up as black holes or:

After a star is born in a nebula, it becomes THIS (before it is classified as low or high mass)

The point of no return (in a black hole)

This is the part of a black hole in which an object can begin to feel its gravity, but can still escape.

Which types of stars can become black holes?

When an object is pulled into a black hole, it gets curved and stretched by the immense amount of gravity. This is called:

The boundary of a black hole

Stellar black holes form from:

Scientists believe there is what type of black hole at the center of every large galaxy?

The universe is estimated to be how old?