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Scientists: our gold came from colliding neutron stars

July 19, 2013
Courtesy of the Har­vard-Smith­son­ian 
Cen­ter for As­t­ro­phys­ics
and World Science staff

The gold on Earth was probably formed in an ex­plo­sive col­li­sion be­tween neu­tron stars—the dead cores of spent stars, ac­cord­ing to a new stu­dy.

Gold is rare on Earth in part be­cause it’s al­so rare in the uni­verse. Un­like el­e­ments like car­bon or iron, it can­not be cre­at­ed with­in a star. In­stead, it must be born in a more cat­a­clys­mic event, sci­en­tists say—like one that oc­curred last month known as a short gam­ma-ray burst. 

Artist's con­cep­tion of two neu­tron stars col­lid­ing (Cour­te­sy CfA)


Ob­serva­t­ions of the burst pro­vide ev­i­dence that it re­sulted from the crash of two neu­tron stars, ob­jects that them­selves are left over from dy­ing, ex­plod­ed stars, phys­i­cists say.

A un­ique glow that per­sisted for days at the burst loca­t­ion po­ten­tially sig­ni­fies the crea­t­ion of sub­stanti­al amounts of heavy el­e­ments, in­clud­ing gold, they add.

“We es­ti­mate that the amount of gold pro­duced and ejected dur­ing the merg­er of the two neu­tron stars may be as large as 10 moon mass­es—quite a lot of bling!” said lead au­thor Ed­o Berger of the Har­vard-Smith­son­ian Cen­ter for As­t­ro­phys­ics.

Berger pre­sented the find­ing July 17 at a press con­fer­ence in Cam­bridge, Mass.

A gam­ma-ray burst is a flash of high-energy light (gam­ma rays) from an ex­tremely en­er­get­ic ex­plo­sion. Most are found in the dis­tant uni­verse. Berger and his col­leagues stud­ied GRB 130603B which, at a dis­tance of 3.9 bil­lion light-years from Earth, is one of the near­est bursts seen to date.

“To par­a­phrase Carl Sagan, we are all star stuff, and our jew­el­ry is colliding-star stuff,” said Berger. The team’s re­sults have been sub­mit­ted for pub­lica­t­ion in The As­t­ro­phys­i­cal Jour­nal Let­ters and are avail­a­ble on­line.


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The gold on Earth was probably formed in an explosive collision between neutron stars—the dead cores of spent stars, according to a new study. Gold is rare on Earth in part because it’s also rare in the universe. Unlike elements like carbon or iron, it cannot be created within a star. Instead, it must be born in a more cataclysmic event, scientists say—like one that occurred last month known as a short gamma-ray burst. Observations of the burst provide evidence that it resulted from the crash of two neutron stars, objects that themselves are left over from dying, exploded stars, physicists say. A unique glow that persisted for days at the burst location potentially signifies the creation of substantial amounts of heavy elements, including gold, they add. “We estimate that the amount of gold produced and ejected during the merger of the two neutron stars may be as large as 10 moon masses—quite a lot of bling!” said lead author Edo Berger of the Harvard-Smithsonian Center for Astrophysics. Berger presented the finding July 17 at a press conference in Cambridge, Mass. A gamma-ray burst is a flash of high-energy light (gamma rays) from an extremely energetic explosion. Most are found in the distant universe. Berger and his colleagues studied GRB 130603B which, at a distance of 3.9 billion light-years from Earth, is one of the nearest bursts seen to date. “To paraphrase Carl Sagan, we are all star stuff, and our jewelry is colliding-star stuff,” said Berger. The team’s results have been submitted for publication in The Astrophysical Journal Letters and are available online.