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A dense, glowing ball of hydrogen, helium, and trace quantities of heavier elements that shines with energy released from a hydrogen thermonuclear fusion reaction in the center, or core. Our Sun is an example of a star. Stars can appear red, orange, yellow, blue, or white, according to their masses and effective temperatures. Stars are born from clouds of gas and dust, live for millions or billions of years, depending on their masses, and die sometimes spectacular deaths. Stars usually exist in very large collections called galaxies.


Cosmic Beacons May 21, 2010

Featured Images

hubble space telescope image of the heart of the star cluster M10

A Plethora of Stars June 26, 2023

simulation depicting the merger of two neutron stars

Defying Gravity May 8, 2023

Young Hothead September 30, 2022

ek draconis

Breathing Fire March 16, 2022

A black hole rips apart a star

The Death of a Star October 14, 2020

Giant bubbles of hot gas form bright splotches on the surface of a red-giant star

Blobby Star December 26, 2017

Sakurai's Object

Flashy Star August 13, 2017

VLT image of three galactic nebulae: M17, M16, and Sharpless 2-54

Galactic Nurseries June 29, 2017

Betelgeuse, Aldebaran, and the Sun

Seeing Orange April 1, 2017

Protoplanetary disks around three young stars

Swirling Planets November 9, 2016

R136, a massive star cluster in the Large Magellanic Cloud

Biggest of the Big July 6, 2016

A star-forming region in the Large Magellanic Cloud

Busy Nursery June 18, 2016

V1331 Cygni, a newly forming star

Almost There June 14, 2016

Infrared image of a bow shock in front of a fast star

Shocking Star January 7, 2016

Jets from a protostar in Serpens

Huffing and Puffng November 6, 2015

Artist's concept of Scholz's Star passing close to the solar system

Former Neighbor May 7, 2015

M3, a globular star cluster

Reborn Stars March 17, 2015

Hubble Space Telescope view of V838 Monocerotis in 2006

Brilliant Echo February 11, 2015

Radio Programs

Deneb Circling around a giant star June 25, 2023

Magnetic Blemishes Blemishes on the face of a star June 12, 2023

Moon and Regulus Spinning off clouds of stardust May 26, 2023

Przybylski’s Star The oddest of odd stars May 20, 2023

A Big Collapse? Small explosions, big black holes September 27, 2022

Moon and Aldebaran “Jiggling” the weight of a star July 22, 2022

Missing Stars Tracking down missing stars April 12, 2022

EK Draconis A fiery outburst from the dragon March 17, 2022

Active Stars Stars with “active” lifestyles March 16, 2022

Strange Matter “Strange” goings-on inside dead stars March 10, 2022

Beta Cassiopeia A star that twirls in a hurry February 11, 2022

Bright Merger A brilliant lightshow from a pair of stars January 6, 2022

Moon and Aldebaran A star that’s losing weight in a hurry December 16, 2021

Big Fades A mysterious fading star December 13, 2021

Age of the Milky Way Measuring the age of the Milky Way November 29, 2021

Moon and Aldebaran A bright star slashes across the sky October 23, 2021

Anti-Stars Looking for anti-stars August 18, 2021

Gliese 710 A possible future menace gets closer June 16, 2021

Hercules Cluster A starry realm that never gets dark June 2, 2021

Moving South A star that’s moving south April 3, 2021

Arcturus Measuring the girth of a big star March 12, 2021

Denebola A bright youngster at the lion’s tail March 7, 2021

Minimal Star A star that’s barely a star January 6, 2021

Population II Stars Stars young and old in the Milky Way August 11, 2020

Faint Neighbors Faint neighbors in the swan July 3, 2020

Moon and Antares The scorpion’s giant heart July 2, 2020

The Stinger The scorpion’s impressive stinger June 25, 2020

Speedy Stars Sending a star on a wild ride May 14, 2020

Counting Candles Counting stellar birthday candles March 20, 2020

Mintaka Big stars with bigger futures March 13, 2020

Moon and Aldebaran Much ado about almost nothing March 1, 2020

Moon and Aldebaran Keeping a star in balance February 3, 2020

More Tabbies Ways to make a star “flicker” December 9, 2019

Solar Twin A star that looks familiar August 26, 2019

Ancient Star An ancient but speedy star June 2, 2019

Zeta Puppis A rare stellar hothead April 7, 2019

Chara Looking into the Sun’s future March 25, 2019

Moon and Aldebaran Squeezing the heart of a star March 12, 2019

Zeta Hydrae Measuring the size of a star February 24, 2019

Starry Treats A bag of goodies for astronomers December 22, 2018

Stars Old and Young Stars old and young December 9, 2018

Speedy Star Speeding through the neighborhood November 2, 2018

Asteroseismology Listening to the beat of the stars September 25, 2018

51 Ophiuchi Squishing a big star September 2, 2018

Ancient Star Looking deep into the past June 17, 2018

Solar Twin A young “twin” of the Sun June 1, 2018

Moon and Antares A stellar weight-loss plan May 29, 2018

Cor Caroli Dark blemishes on a big star April 22, 2018

More ‘O’ Stars Big stars with a big influence April 13, 2018

‘O’ Stars The showiest stars in the galaxy April 12, 2018

Twinkling Twinkle, twinkle, little star December 23, 2017

Rho Cassiopeia Practicing for a big blast November 22, 2017

Close Encounters A dangerous encounter with a star November 1, 2017

Moon and Companions Cranking up a giant star September 25, 2017

Moon and Aldebaran The “shifty” eye of the bull September 11, 2017

Giant Magellan Telescope II Getting to know distant planets August 10, 2017

Future Fireworks Getting ready for some fireworks June 29, 2017

Red Nova An exploding star turns red June 28, 2017

Orange Triplets Three orange stars for the price of one June 24, 2017

Messier 5 Some of the oldest stars in the galaxy June 11, 2017

Menkent An over-represented class of stars June 1, 2017

Closing In A busy, far-away source of radio waves May 23, 2017

Gienah Stirring up a star’s ingredients April 16, 2017

Seeing Orange Puffing up like orange balloons April 1, 2017

Making Elements III Heavy stars make heavy elements March 8, 2017

Making Elements II Making elements in the hearts of stars March 7, 2017

Counting Starspots Counting spots on a small star March 3, 2017

Heartbeat Stars Watching stars change shape February 6, 2017

Gomeisa Spinning out a stellar cloud February 4, 2017

Moon and Regulus Learning about a familiar star January 14, 2017