Mass & Star Future
Life cycle of Stars
Heart of the star
Stellar Structure
Bonus round
100

This initial cosmic cloud of gas and dust collapses under gravity to form a hot, dense protostar, marking the very first stage in a star's journey before nuclear fusion ignites.

What is a giant molecular cloud?

100

This initial, vast collection of gas and dust is where a star's journey begins, eventually collapsing to form denser regions.

What is a giant molecular cloud?

100

This famous nuclear reaction, in Stars like our sun where hydrogen atoms fuse to form helium.

What is the Proton Proton Chain

100

 This zone of a star is where energy is transported outward primarily through the absorption and re-emission of photons

What is the Radiation Zone?

100

What amazing process happens deep inside a star's core that makes it shine so brightly and generate its own heat? What is nuclear fusion?

What is nuclear fusion?

200

A star with an initial mass similar to our Sun will spend billions of years in this stable phase, fusing hydrogen, before expanding into a red giant and eventually shedding its outer layers to become a white dwarf with a final mass typically less than 1.4 solar masses.

 What is the main sequence?

200

This stellar remnant is held up by the pressure of electrons packed tightly together, a state known as electron degeneracy, but it cannot exist if its mass exceeds a critical value, often cited around 1.4 solar masses. What is a white dwarf?

What is a white dwarf?

200

This cycle involving carbon nitrogen and oxygen is the dominant fusion process for forming helium in Stars much more massive than the sun.

 What is the CNO cycle

200

In this turbulent layer, hot plasma rises, cools, and then sinks, effectively transferring energy to the star's outer regions.

What is the Convection Zone?

200

Our Sun and about 90% of all other stars, including giant blue ones and tiny red dwarfs, are classified as being in this primary, stable life stage where they fuse hydrogen in their core.

What is the main sequence?

300

A star with an initial mass exceeding about 8-10 times that of the Sun is destined to end its life in a cataclysmic explosion and collapse into either a neutron star or, if even more massive, a black hole.

What is a supernova?

300

This incredibly dense object forms from the core collapse of a massive star, so compact that its matter is supported by the pressure of neutrons, a state called neutron degeneracy.

What is a neutron star?

300

Stars can fuse elements all the way up to this specific metal, but trying to go heavier actually costs more energy than it releases.

What is iron?

300

Often referred to as the "surface" of the sun, this visible layer is where the light we see is emitted.

What is the Photosphere?

300

This cosmic mystery has such an intense gravitational pull that once you cross its event horizon, nothing, not even light, can ever escape.

What is a black hole?

400

This diagram plots a star's temperature against its luminosity, illustrating how stars of different initial masses follow distinct evolutionary tracks, including a long horizontal stretch and various loops or excursions from the main sequence.

What is the Hertzsprung-Russell (HR) Diagram?

400

This cosmic entity, often the end-stage for the most massive stars, has a gravitational pull so immense that nothing, not even light, can escape once past its event horizon.

what is a black hole?

400

A single photon can take this incredibly long time to escape the dense stellar interior before reaching earth.

what is hundreds of thousands of years

400

Above the photosphere, this reddish, spiky layer of a star's atmosphere is best observed during eclipses.

What is the Chromosphere?

400

Before a star is even born, it starts as a super-dense lump of gas and dust right in the middle of a giant space cloud.

What is a cloud core?

500

Whether a star ends its life as a white dwarf, a neutron star, or even a black hole is entirely determined by this critical property it possesses at the very beginning of its life.

What is a star's initial main-sequence mass?

500

In this stable phase, a star like our Sun fuses hydrogen into helium in its core, maintaining a balance between gravity and internal pressure. What is a main sequence star?

What is a main sequence star?

500

In Stars greater than this solar mass the CNO cycle becomes the dominant energy producing process for these star

what is 1.3 solar masses

500

This outermost and hottest layer of a star's atmosphere extends millions of kilometers into space and is responsible for the solar wind.

What is the Corona?

500

When a star like our Sun reaches the end of its life, it puffs out its outer layers into a beautiful, colorful ring or cloud of gas.

What is a planetary nebula?

600

much larger stars burn through their fuel incredibly fast, often lasting only a few million years. This shows how a star's initial mass affects its time spent in this main, stable phase.

What is the relationship between a star's mass and its main-sequence lifetime?

600

This cosmic entity, often the end-stage for the most massive stars, has a gravitational pull so immense that nothing, not even light, can escape once past its event horizon.

 What is a black hole?

600

This crucial balance within a star's very center describes the perfect standoff between the immense inward pull of gravity and the powerful outward pressure generated by the star's nuclear furnace.  

What is thermo-gravitational equilibrium

600

These cooler, darker regions on the Sun's visible surface are caused by concentrated magnetic fields inhibiting convection.

What are Sunspots?

600

This specific point marks a star's "official birth," when it first stabilizes and begins to continuously fuse hydrogen into helium in its core, settling onto its longest life stage.  

What is the Zero-Age Main Sequence

M
e
n
u