Mr Calaski

Home » Science » Astronomy » Stars & Galaxies

Stars & Galaxies



1) After watching Wonders of the Universe – Stardust, I can…

a.) …estimate the number of stars in a typical galaxy.

b.) …illustrate the life cycles of  low mass and high mass stars.

c.) …identify how and where chemical elements are produced.

2a.) After the spectral analysis lab, I can analyze a light spectrum from a star to determine what elements the star contains.

Learning Standard

ES 12. Recognize that the universe contains many billions of galaxies, and that each galaxy contains many billions of stars.


Main Ideas

  1. There are approximately 100 billion stars in the Milky Way galaxy, and billions of galaxies in the universe.
  2. Chemical elements are the basic ingredients of all life and matter, and they are forged in the furnace of stars.
  3. The entire universe, including Earth, contains the same 92 natural elements.
  4. Scientists can analyze the absorption lines of starlight on a spectrogram to determine which elements are present in a star.
  5. The first 26 elements are created in small to average sized stars like our Sun, but these stars do not produce the temperatures high enough to forge heavier elements.
  6. The heaviest elements, like gold, platinum, uranium, can only be produced in high mass stars because these stars are the only place in the universe that can reach 100 billion degrees Celsius (during a supernova).
  7. After a supernova, elements forged in a dying star are dispersed in an enormous chemical cloud of gas, dust, and elements called a nebula.
  8. Complex chemistry occurs in a nebula forming new molecules and compounds that will eventually become new stars, planets, celestial objects, and solar systems; just like the chemistry that occurred from the nebula that helped form our Sun and solar system.


Life Cycle of Star / Evolution of Stars





Jump To:

Space Technology

Electromagnetic Spectrum (EMS)

Solar System


Earth’s Seasons

Moon Phases



Stars & Galaxies

Study Guide:  Unit Test


%d bloggers like this: