An erupting, massive star in the Milky Way. NASA's Hubble Space Telescope has identified one of the most massive stars known, emitting as much as 10 million times the power of our Sun and with a radius larger than the distance between the Sun and the Earth.
Click on image for full size
Image courtesy of NASA, Space Telescope Institute

Fusion Inside the Stars

Fusion in the core of stars is reached when the density and temperature are high enough. There are different fusion cycles that occur in different phases of the life of a star. These different cycles make the different elements we know. The first fusion cycle is the fusion of Hydrogen into Helium. This is the stage that our Sun is in.

In stars with a very high temperature there are other fusion cycles that take place(CNO cycle). At higher temperatures, Helium burning produces Carbon. Finally, at even higher temperatures the heavier elements like Iron are formed.

The fusion reactions occurring in stars makes neutrinos that reach Earth. By detecting these neutrinos, scientists learn about fusion inside the stars.


Shop Windows to the Universe Science Store!

Cool It! is the new card game from the Union of Concerned Scientists that teaches kids about the choices we have when it comes to climate change—and how policy and technology decisions made today will matter. Cool It! is available in our online store.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Hematite with Rutile

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Fusion Reactions

Nuclear fusion is a process where two or more nuclei combine to form an element with a higher atomic number (more protons in the nucleus). Fusion is the reverse process of nuclear fission. Fusion reactions...more

The Hydrogen Fusion Process

In the basic Hydrogen fusion cycle, four Hydrogen nuclei (protons) come together to make a Helium nucleus. This is the simple version of the story. There are actually electrons, neutrinos and photons involved...more

Neutrino detectors

Neutrino interactions with matter are extremely rare, so detecting a neutrino is very hard. Neutrino detectors are typically large, underground tanks filled with a fluid that reacts to the passage of neutrinos....more

Diagnostics for the Solar Interior

The Sun releases energy. The processes that make this energy take place in the center of the Sun. We can't see past the surface of the Sun. But scientists use indirect ways (diagnostics) to figure out...more

Fusion Inside the Stars

Fusion in the core of stars is reached when the density and temperature are high enough. There are different fusion cycles that occur in different phases of the life of a star. These different cycles make...more

The Neutron Capture Process

Neutron capture can occur when a neutron approaches a nucleus close enough for nuclear forces to be effective. The neutron is captured and forms a heavier isotope of the capturing element. When the new...more

The Supernova

A Supernova is a very massive star that explodes at the end of its life cycle. The supernova is the furnace where the heavy elements (heavier than iron) are formed. ...more

Shop Windows to the Universe

Fossil shark's teeth are available in our online store, along with other minerals and fossils, books, activities, jewelry, and household items.

Generous sponsorship of Windows to the Universe is provided by the Hewlett Foundation, the American Geological Institute, the American Geophysical Union, the National Science Foundation, NASA, NCAR, and the CISM and CMMAP projects. NASA CMMAP AGU CISM NCAR Hewlett AGI NSF