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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

Radio Programs

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

Moon and Spica Making stellar companions December 22, 2016

Achernar A star with a bulging waistline November 27, 2016

Bellatrix A truly “bewitching” star November 26, 2016

Twinkling Twinkle, twinkle, every star October 30, 2016

VV Cephei A “kingly” star in the northern sky October 26, 2016

Old Clusters Scanning for the distant past September 30, 2016

Moon and Aldebaran Moving toward a moving target August 24, 2016

Few Suns A lack of Sun-like stars in the night sky August 20, 2016

Altair Spinning up a big, young star July 17, 2016

Heaviest Star A star with a weight problem July 6, 2016

Delta Lyrae Contrasting colors in the harp June 25, 2016

Moon and Regulus Spinning off a colorful cloud June 9, 2016

Eltanin “Shifty” drops of starlight June 4, 2016

Vega Getting the right angle on a star June 1, 2016

Bigger and Hotter Jacking up a star’s brightness — after this. January 11, 2016

Sheratan The hidden nature of a binary star October 24, 2015

Mirach Stars at opposite ends of the scale September 28, 2015

Quick Change A star that’s changing in a hurry August 7, 2015

Moon and Aldebaran Similar but different lights near the Moon August 6, 2015

First Stars II Brilliant clusters in the early universe July 16, 2015

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

Stellar Metals A difference between young and old stars July 14, 2015

M92 An ancient family of stars May 12, 2015

M13 A cluster of old, faint stars May 11, 2015

Fast Neighbor A “runaway train” in the stars May 5, 2015

Alphard A long but barren constellation March 22, 2015

MY Camelopardalis A brilliant duet for the giraffe March 14, 2015

Fewer New Stars A decline in the stellar birth rate February 25, 2015

Bright Merger The fireworks of a hostile takeover February 10, 2015

Filling the Void Filling the intergalactic void January 18, 2015

Trapezium Lighting up a galactic trapeze January 16, 2015

Sirius Rising The Dog Star climbs into winter evenings January 3, 2015

Superflares A big outburst from a tiny star December 2, 2014

Rara Avis II Dancing with the firebird November 29, 2014

Doomed Giant A big star with a brilliant future September 23, 2014

Biggest of the Big The monsters of the Milky Way September 22, 2014

Moon and Companions The little dog leads the big dog September 17, 2014

EQ Pegasi A pair of juvenile stellar neighbors September 11, 2014

The Neighborhood Getting to know the neighbors August 6, 2014

RECONS Taking a census of our stellar neighborhood August 5, 2014

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

Moon and Antares Siblings that age at different rates July 7, 2014

Alphecca Stellar siblings with different futures June 27, 2014

Moon and Spica Violent scenarios for a binary star May 10, 2014

Beta Coma Berenices A star that’s a lot like our own April 25, 2014

Runaway Stars Stars that are leaving home in a hurry April 10, 2014

Zeta Cas A star that's far above average... February 22, 2014

Moon and Aldebaran Taking the measure of the bull’s eye February 6, 2014

Life of Procyon The life of the Little Dog Star December 27, 2013

More Aquarius A pair of yellow supergiants December 7, 2013

Fomalhaut Surprises from a well-studied star October 13, 2013

Equuleus Two stars whose fates are intertwined August 23, 2013

Counting Stars Counting the stars in the Milky Way July 25, 2013

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

Solar Twins A star that looks familiar May 31, 2013

Twinkling Jewels Up-and-down stars in the northern crown May 29, 2013

Messy Giant Kicking up dust around a giant star April 11, 2013

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

Groombridge 1830 An interloper from a distant realm March 30, 2013

Ringing Beat The beat of vibrating stars March 5, 2013

Moon and Antares A hot-but-cool stellar supergiant February 3, 2013

Superflares Super explosions on other stars January 22, 2013

Epsilon Geminorum A star by the numbers January 16, 2013

Pollux Younger but “older” than the Sun January 15, 2013

Moon and Spica Giant tides on giant stars January 3, 2013

Star Populations Segregating the stars of the Milky Way December 2, 2012

Halloween Star A two-headed stellar demon October 29, 2012

Aries II Taking the measure of a nearby star October 27, 2012

Alpha and Beta Aquarii Rare supergiant stars October 22, 2012

Arcturus Tracing a star’s origins August 27, 2012

M11 A flock of young stars August 8, 2012

Spinning Hearts The spinning hearts of giant stars August 1, 2012

Equuleus Drawing up a little horse July 28, 2012

Moon and Scorpius Scoping out a solar twin July 26, 2012

H-R Diagram Drawing the lives of the stars July 6, 2012

Faint But Steady Stars that are faint but long-lived July 4, 2012

The Keystone Four stars, four stories May 24, 2012

Moon, Mars, and Regulus Different pinpoints of light April 1, 2012

Featured Images

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

Superflare on one of the stars of DG Canum Venaticorum

Tiny Star, Big Outburst December 3, 2014

A rare yellow hypergiant star in Centaurus

Jolly Yellow Giant March 13, 2014

A discharge of energy from the Z Machine at Sandia National Laboratories

Zapped! February 3, 2014

The star Gamma Cas blows away gas from a nearby nebula

Star Blaster August 18, 2013

View of the 30 Doradus star cluster and the massive binary system R144

Megastars July 9, 2013

Artist's concept of the Sun's structure

Powerhouse December 17, 2012

H-R Diagram

Stellar Plot July 7, 2012

Rings and bubbles from a dying star

Jumping Through Hoops August 5, 2010

Youthful Oldies March 4, 2010