Skip Navigation

14.4: Star Formation

Difficulty Level: Basic Created by: CK-12
Atoms Practice
Estimated1 minsto complete
Practice Star Formation
This indicates how strong in your memory this concept is
Estimated1 minsto complete
Estimated1 minsto complete
Practice Now
This indicates how strong in your memory this concept is
Turn In

Can you see stars being born?

On a dark night you can practically watch stars being born. The fuzzy area in the sword in the constellation Orion is the Orion nebula. A close up shows the nebula with around 3,000 stars. New stars are being born there.

Star Lives

Stars have a life cycle, just like people. Stars are born, grow, change over time, and eventually grow old and die. Most stars change in size, color, and class at least once in their lifetime. What astronomers know about the life cycles of stars comes from data gathered from visual, radio, and X-ray telescopes.


Stars are born in a cloud of gas and dust called a nebula (Figure below). Our Sun and solar system formed out of a nebula.

Stars form inside the Rosette Nebula

Stars are forming in the Rosette Nebula.

The Pillars of Creation (Figure below) are within the Eagle Nebula. The pillars are thought to be a large region where stars are forming. The dark areas may be stars that are about to begin.

The Pillars of Creation is an active region of the Eagle Nebula where new stars are being formed

In the Pillars of Creation, gas and dust come together as a stellar nursery.

Star Formation

For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star!

Our Sun was probably born in a nebula, like Orion in the top image.


  • Stars form in a nebula.
  • A nebula is a cloud of dust and gas.
  • Nebulae can be spotted with the naked eye or simple telescopes.


  1. What is a nebula?
  2. How do stars form?
  3. Why do scientists think the Pillars of Creation are where stars are forming?

Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes
Show More


nebula Cloud of dust and gas where stars form.

Image Attributions

Show Hide Details
Difficulty Level:
6 , 7
Date Created:
Jan 04, 2013
Last Modified:
Aug 29, 2016
Save or share your relevant files like activites, homework and worksheet.
To add resources, you must be the owner of the Modality. Click Customize to make your own copy.
Please wait...
Please wait...
Image Detail
Sizes: Medium | Original