Category 1: The Mass Cascade
In the Mass Cascade, an increase in a star’s mass directly leads to an increase in this inward-pulling fundamental force.
What is gravitational force (or gravity)?
Over 90 percent of all stars in the universe, including our Sun, belong to this central band on the H-R Diagram.
What is the Main Sequence?
Every star begins its life cycle inside a large cloud of gas and dust known as this.
What is a nebula?
During their main sequence phase, all stars convert hydrogen into this light element through nuclear fusion.
What is helium?
Betelgeuse has a temperature of 3,400 K and a radius 1,000 times that of the Sun. Infer its color.
What is red (or reddish-orange)?
Increased gravity and pressure inside a star's core leads to higher levels of this measurement, creating the necessary
What is temperature?
Unlike most standard graphs, the x-axis (temperature) on an H-R diagram is unusual because it runs in this direction.
What is backward (or decreasing from left to right / hot to cool)?
After a low-to-medium mass star expands into a Red Giant, its outer gas layers drift away into space, forming this expanding shell of gas.
What is a planetary nebula?
Low and medium-mass stars in the Red Giant stage are able to fuse lighter elements up to this common element.
What is Carbon?
Sirius B has a temperature of 25,200 K and a luminosity of 0.056. Identify its current life cycle stage.
What is a White Dwarf?
According to the Mass Cascade chain, increased gravitational force directly causes an increase in this inward physical force inside the core.
What is pressure?
These small, hot, dim leftover cores of dead low-to-medium mass stars are found in the bottom-left corner of the H-R Diagram.
What are White Dwarfs?
A high-mass star’s life ends in a catastrophic, brilliant explosive event called this.
What is a supernova?
High-mass stars in the Red Supergiant phase can fuse heavier elements in their core up to this element (Atomic Number 26), which stops nuclear fusion.
What is Iron (Fe)?
Procyon B has a mass of 0.60 Suns. What will be the ultimate end product of its life cycle after it cools completely?
What is a Black Dwarf?
Fill in the blanks: Increased Mass → Increased Gravitational Force → Increased Pressure → Higher Core Temperature → Conditions for ____ ____.
What is Nuclear Fusion?
A star with a very low temperature (e.g., 3,400 K) but extremely high brightness/luminosity (e.g., 9,500 Suns) is classified as this type of star.
What is a Red Supergiant (or Supergiant)?
Depending on its remaining mass after a supernova explosion, a high-mass star will become either a neutron star or this extreme object with gravity so strong light cannot escape.
What is a black hole?
Naturally occurring elements heavier than iron, up to uranium, are synthesized during this short, explosive event.
What is a supernova?
Antares has a mass of 12.4 Suns. Because its mass is between 3x and 20x the mass of the Sun, what will its core become after a supernova?
What is a neutron star?
Explain why a high-mass star lives a much shorter life than a low-mass star based on the Mass Cascade.
What is because greater mass leads to extreme gravitational force, pressure, and temperature, causing the star to burn through its fuel at a dramatically faster rate?
If Star A and Star B have the exact same temperature, but Star A is 10,000 times more luminous than Star B, Star A must have a much larger value for this physical property.
What is radius (or size)?
Place these stages of a Sun-like star in chronological order: White Dwarf, Protostar, Red Giant, Nebula, Main Sequence.
What is Nebula → Protostar → Main Sequence → Red Giant → White Dwarf?
All elements heavier than Uranium (Atomic Number 92) on the periodic table share this unique origin.
What is being man-made (synthetic)?
Regulus has a mass of 3.8 Suns, a temperature of 12,460 K, and a luminosity of 140. Predict its ultimate pathway from start to finish.
What is Nebula → Protostar → High-Mass Main Sequence → Supergiant → Supernova → Neutron Star (or Black Hole)?