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Origin and Nature of the Sun

Infographic showing possible paths of the stellar life cycle, with two main pathways: Sun-like Stars (left) and Massive Stars (right). Both paths begin and end with a red cloud labeled "Star-Forming Nebula." The Sun-like Star path runs counterclockwise from "Star-Forming Nebula" in the middle to "Protostars," then "Sun-like Star," then "Red Giant," and then to “Planetary Nebula." Two paths lead off from "Planetary Nebula," one to "White Dwarf" and the other back to "Star-Forming Nebula." The Massive Star path runs clockwise from "Star-Forming Nebula" to "Protostars," then "Massive Star," then "Red Supergiant," and then to "Supernova." Three paths lead off from "Supernova": "Black Hole," "Neutron Star," and "Star-Forming Nebula." The Sun-like Star path is longer than the Massive Star path. Labels along the paths indicate that the time between the formation of a Sun-like star and a Red Giant star is billions of years, and the time between the formation of a massive star and a Red Supergiant is millions of years
A star's life is a constant struggle against the force of gravity. Gravity constantly works to try and cause the star to collapse. The star's core, however, is very hot, which creates pressure within the gas. This pressure counteracts the force of gravity, putting the star into what is called hydrostatic equilibrium. A star is okay as long as the star has this equilibrium between gravity pulling the star inwards and pressure pushing the star outwards. During most of a star's lifetime, the interior heat and radiation is provided by nuclear reactions in the star's core. This phase of the star's life is called the main sequence. Before a star reaches the main sequence, the star is contracting and its core is not yet hot or dense enough to begin nuclear reactions. So, until it reaches the main sequence, hydrostatic support is provided by the heat generated from the contraction. At some point, the star will run out of material in its core for those nuclear reactions. When the star runs out of nuclear fuel, it comes to the end of its time on the main sequence. If the star is large enough, it can go through a series of less-efficient nuclear reactions to produce internal heat. However, eventually these reactions will no longer generate sufficient heat to support the star against its own gravity and the star will collapse.
Levels
  • Advanced (9-12+)
Material Type
  • Activity/Hands-on
  • Lesson Plan
  • Interactive/Game/Simulation
Heliophysics Big Ideas
  • Big Idea 3.3 - Our Sun, like all stars, has a life cycle.
NGSS
  • PS2 - Motion and Stability: Forces and Interactions
  • PS3 - Energy
  • ESS1 - Earth's Place in the Universe
Heliophysics Topics
  • Magnetic Field
  • Sunspot
  • Sun
  • Solar Cycle
  • Solar Flare
Heliophysics Missions
  • Solar Dynamics Observatory (SDO)
  • Parker Solar Probe
Material Cost per Learner Free
Language English

In this 5E lesson, middle school students explore the origin of the Sun using scientific and traditional ways of tracing how the Sun came into existence.

Find The Full Lesson Plan Here