Exploring stages from nebula to black hole or neutron star

• What are the key stages in the life cycle of a star?

  • Stellar Nebula
  • Average Star
  • Red Giant
  • Planetary Nebula
  • White Dwarf
  • Supernova
  • Neutron Star
  • Black Hole
• A black hole is one of the possible remnants of a supernova.

  True
• What are the two possible remnants of a supernova event?

  Neutron star or black hole
• What do the different regions in the image represent?

  • The different regions represent different spectral classes of stars:
  • V Main Sequence
  • IV Subgiants
  • III Bright Giants
  • Ia Supergiants
  • Ib Supergiants
  • White Dwarfs
• What is the name of the star at the end of the main sequence stage?

  White dwarf
• Nebulae are primarily composed of gas and dust.

  True
• What is the temperature range shown in the image?

  • Temperature range shown is from 3000K to 10000K
• What happens when a main sequence star runs out of hydrogen fuel in its core?

  Nuclear fusion stops
• A denser core within a nebula is the precursor to a protostar.

  True
• What type of astronomical object or phenomenon is being observed in the bottom row of images?

  Star-forming regions
• What causes the core of a nebula to heat up during gravitational collapse?

  Gravitational collapse
• How does the position of a star on the color-magnitude diagram relate to its evolutionary stage?

  Stars on the main sequence are in their normal hydrogen-burning stage, while stars above and below the main sequence are in later evolutionary stages
• How can the absolute magnitude of a star be determined from the information in the image?

  • The absolute magnitude of a star can be determined from its position on the color-magnitude diagram (Hertzsprung-Russell diagram) shown in the image.
• Steps in the transformation of a main sequence star into a red giant

  1️⃣ Main sequence star uses hydrogen fuel

  2️⃣ Nuclear fusion stops in the core

  3️⃣ Outer layers expand

  4️⃣ Star becomes a red giant
• What is the primary nuclear fusion reaction in main sequence stars?

  $4H \rightarrow He +$$energy$
• The main sequence band on the Hertzsprung-Russell diagram shows the relationship between luminosity and temperature for stable stars.

  True
• What is the formula to calculate the absolute magnitude (M) of a star?

  $M =$$m - 5\log_{10}(d) +$$5$
• If a star has an absolute magnitude of 5 and is located at a distance of 10 parsecs, what is its apparent magnitude?

  $m =$$M +$$5\log_{10}(d) - 5 =$$5 +$$5\log_{10}(10) - 5 =$$10$
• What is the primary source of energy for main sequence stars?

  Nuclear fusion
• What is the name given to a star before it becomes a main sequence star?

  Protostar
• What is the first stage in the life cycle of a star?

  Stellar Nebula
• How does the life cycle of a high mass main sequence star (e.g. Rigel) differ from a low mass star (e.g. the Sun)?

  High mass star becomes a red supergiant instead of a red giant
• What type of star will our Sun eventually become?

  White Dwarf
• Why are the different spectral classes of stars labeled on the color-magnitude diagram?

  To show how the properties of stars, such as temperature and luminosity, vary across the different spectral classes
• How do red giants and supergiants differ from their main sequence forms in size and temperature?

  Larger and cooler
• A supernova explosion blasts away a massive star's outer layers.

  True
• What triggers nuclear fusion in the outer layers of a massive star during a supernova event?

  Core collapse
• What are the main stages of stellar evolution for low- and medium-mass stars?

  • Main sequence
  • Red giant
  • "Planetary" nebula
  • White dwarf
• What are the main stages of stellar evolution for high-mass stars?

  • Main sequence
  • Red supergiant
  • Supernova
  • Neutron star or black hole
• How does the mass of a star determine its life cycle?

  • Low mass stars: Become Red Giants, then White Dwarfs
  • High mass stars: Become Supernovae, then Neutron Stars or Black Holes
• What is the purpose of the "planetary" nebula stage in the stellar evolution process?

  It is the stage where the star ejects its outer layers, forming a colorful nebula
• If a star has a radius of 5 cm, what is its area?

  $25\pi \text{ cm}^2$
• If a star is currently in the "planetary" nebula stage, what is the next stage in its evolution?

  White dwarf
• Neutron stars can rotate hundreds of times per second.

  True
• What is the formula to calculate the area of a circle?

  Area = $\pi r^2$
• How does the evolution of high-mass stars differ from low- and medium-mass stars?

  High-mass stars end their lives in a supernova explosion, while low- and medium-mass stars form a planetary nebula and become white dwarfs
• What is the event horizon of a black hole?

  Point beyond no escape
• What is the process that forms a black hole after a supernova?

  Gravitational collapse
• What is the density of a neutron star in kg/m³?

  $3 \times 10^{17}$
• Steps in the formation of a nebula leading to star birth

  1️⃣ Gravity pulls gas and dust together

  2️⃣ Nebula clumps and condenses

  3️⃣ A denser core forms