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Nuclear Fusion

A reaction that involves two atomic nuclei merging to create the nucleus of a new atom. The reaction is accompanied by a tremendous release of energy. The Sun’s energy, as with all stars, comes from nuclear fusion reactions that happen in its core. The reactions fuse hydrogen nuclei into helium nuclei. About 0.7 percent of the mass of the hydrogen is converted to energy, which makes the star shine.


Aries, the ram

Aries, the Ram October 4, 2011

Sun cutaway

Star Color and Energy May 21, 2010

Radio Programs

Moon and Aldebaran Things get complicated for a star September 20, 2016

More Hydrogen The most abundant element in the universe May 29, 2016

R Sculptoris Stirring up a stellar bubble December 11, 2015

Confirmation Particles from the heart of the Sun October 28, 2015

Alpha Persei A young star ages in a hurry October 8, 2015

The First Stars Whipping up the first stars July 15, 2015

Moon and Aldebaran Igniting the core of a star July 10, 2015

Fred Hoyle Unlocking the secrets of the stars June 23, 2015

Vega A middle-aged star with a difference June 5, 2015

Brighter Sun The Sun gets a lot brighter April 27, 2015

Solar Fusion The Sun shines on and on and on April 26, 2015

Iron Ironing out a heavy element February 4, 2015

Moon and Aldebaran Making carbon and oxygen in a star November 6, 2014

Great Square The above-average stars of the Great Square September 8, 2014

Outcast Star A stellar outcast in the Big Dipper July 21, 2014

Moon and Aldebaran Changing a delicate balancing act July 20, 2014

Oxygen Breathing a creation of the stars June 18, 2014

Making Nitrogen Breathing the “ash” of dead stars February 16, 2014

Z Machine II The power source of the stars February 3, 2014

Wezen Dumping chemicals into space January 28, 2014

Moon and Jupiter Heating up a giant planet December 17, 2013

Capella A pair of bright, “puffy” stars November 18, 2013

Moon and Aldebaran The beginning of the end July 3, 2013

Colorful Arcturus Adding some color to a bright star June 22, 2013

Gamma-2 Velorum A star exposes its inner workings April 4, 2013

Polaris II The un-steady beat of the North Star February 19, 2013

Moon and Antares Building a stellar onion January 6, 2013

The Sun II The long trip before the journey begins December 17, 2012

The Sun Powering up the Sun December 16, 2012

Triangulum Aging stars in the triangle November 2, 2012

Unproductive Sun Outshining the Sun — sort of June 17, 2012

Capella A quick exit for a “heavy” star April 26, 2012

Star in a Bottle Making a bottleful of starstuff April 12, 2012

Supernova 1987A Blasting a giant star to bits February 20, 2012

White Dwarfs Squeezing the heart of a dead star January 31, 2012

Betelgeuse A superstar among supergiants November 30, 2011

Alpha Persei A young but aging star October 7, 2011

Pollux Forging the element of life May 14, 2011

Gienah A young-but-old star April 1, 2011

Denebola Shining through the moonlight March 17, 2011

Stellar Factory Forging elements in a stellar factory February 14, 2011

Featured Images

Abell 78, a planetary nebula

Last Round July 28, 2015

Rings and bubbles from a dying star

Jumping Through Hoops August 5, 2010

A Dose of Magnesium January 20, 2010