Life Cycle of a Star Worksheet

Tara Kunesh
boy gazing at star

Stars may be balls of gas and dust held together by gravity, but they are also the iconic lights of the night. Learning about stars will add understanding to the sense of awe you feel as you gaze up into the sky. Stars are "born," age and die and the study of their life cycle unlocks one of the mysteries of astronomy.

Star Life Cycle Worksheet

These printables on the star life cycle include a vocabulary worksheet and a diagram of the start life cycle that you can fill out, along with answer keys. To download the printable, click on the link and it will open in a new tab. From there, you can download or print the lesson. This guide can help you troubleshoot if you get stuck.

Lesson Ideas

You can incorporate this worksheet into several lesson plans covering astronomy. The worksheet itself is suitable for third graders and up, but can be adapted to suit different grade levels and abilities. For those requiring a more challenging middle or high school plan, the life cycle chart and vocabulary can form part of a longer astronomy unit. The NASA website contains a variety of high-level plans suitable for grades six to twelve which also incorporate math and other scientific principles into the lesson ideas.

Star Life Cycle Lesson

Stars are born in nebulae; clouds of gas and dust located in space. Turbulence and gravity instigate a fusing effect, causing the center of the dust and gas area to heat up and become what is known as a protostar. This brand new beginning of a star will, in time, become a full star which will then age and die according to the dictates of the star life cycle.

The Star Life Cycle

This star chart demonstrates the two main life cycle pathways which stars follow, depending on their mass and size. The stars which follow the left-hand pathway are those which are approximately the same size as the Earth's sun. The Earth's sun is an average-sized, middle-aged star which should remain stable for billions of years.

Star Live Cycle Diagram

Stars which are much bigger than the sun; those, according to NASA, with a mass of over eight solar masses, or eight times the mass of the Earth's sun, will follow the right-hand pathway. These rare giant stars will, when they die, become supernovae. Then, depending on the mass of their core, they will become either neutron stars or black holes. As with any life cycle, the debris formed from the supernovae will result in the eventual formation of new stars. The NASA science website explains this process in great depth.

Vocabulary to Know

  • Black Dwarf - a white dwarf star that has cooled down to the temperature of the background and has become invisible
  • Black Hole - a region of space with a gravitational field so strong that no matter or radiation can escape from it
  • Nebula - a cloud of dust and gasses in space. The plural of nebula is nebulae
  • Neutron Star - a type of star sometimes created when giant stars die in supernovae, and their cores collapse
  • Protostar - the earliest formation of a star
  • Red Dwarf - a small, aging, and relatively cool star
  • Red Giant Star - a large, dying star in the last stages of its evolution
  • Red Super Giant Star - a star in the last stage of its evolution
  • Stellar Nursery - an area in space where new stars are formed
  • Supernova - an explosion that takes place at the end of a binary (two stars together) or a giant star's life cycle
  • White Dwarf - a low or medium mass star in the last stages of its evolution

Additional Resources has a helpful list of activities and experiments for all different ages. For example, there is an activity for high school students in which the life cycles of humans and stars are observed, compared and classified. For elementary students and above, a fun and adaptable enhancement idea is Stanford Solar Center's "Interview Mr. Sol Activity."

Go Outside

For an authentic and rewarding experience, add learning about constellations to your study of stars and their life cycles. Find Orion, the North Star, Ursa Major and more from the comfort of your backyard. has a helpful site containing pictures of various constellations you can spot without the use of equipment. It is organized by whether you live in the Northern or Southern Hemisphere, what season you are in, and the direction of your view.

Life Cycle of a Star Worksheet