Journal Express, Knoxville, IA

CNHI/SE Iowa

July 18, 2013

Origin of gold found in rare neutron-star collisions

(Continued)

Most of these cosmic fruitcakes are solitary wanderers, but some are paired up, as remnants of binary stars. They will orbit a common point in space and gradually drift closer and closer, spiraling toward one another in obedience to Einstein's laws of general relativity. One day, they will collide.

In the Milky Way galaxy, with hundreds of billions of stars, such a neutron-star collision is likely to happen about once every 100,000 years, Berger said.

Astronomers are fortunate in that the universe is so vast, containing many billions of galaxies, that any all-sky survey might possibly see something even as rare as a neutron-star collision. So it was that on June 3, NASA's Swift space telescope observed a flash of light, called a short gamma-ray burst (GRB), in an extremely distant galaxy in the constellation Leo.

Astronomers scrambled to reobserve that tiny patch of space with a powerful telescope in Chile and with the Hubble Space Telescope.

They saw something glowing where they'd earlier seen the GRB. After comparing their observations with theoretical models, the astronomers concluded that they were seeing the radioactive afterglow from a huge quantity of heavy metals formed by a neutron-star smashup.

This observation potentially explains this type of short-duration GRB. These flashes of light can briefly outshine an entire galaxy. The June event, in a galaxy 3.9 billion light-years away, lasted only two-tenths of a second.

Although neutron-star collisions had been proposed as a source of such GRBs, now there is a direct observation.

"When they make contact, several exciting things happen very quickly," Berger said. "Most of the material actually collapses to form a black hole. Some of the material then gets sucked into the black hole. That is the event that causes the gamma-ray burst. Some of the material gets spewed out into space. That material, since it came from neutron stars, is very rich in neutrons, and as a result, is very efficient at forming these heavy elements, including gold."

Text Only
CNHI/SE Iowa
  • Sunburn isn't the only sign of summer that can leave you itchy and blistered

    You've got a rash. You quickly rule out the usual suspects: You haven't been gardening or hiking or even picnicking, so it's probably not a plant irritant such as poison ivy or wild parsnip; likewise, it's probably not chiggers or ticks carrying Lyme disease; and you haven't been swimming in a pond, which can harbor the parasite that causes swimmer's itch.

    July 30, 2014

  • Survey results in legislation to battle sexual assault on campus

    Missouri U.S. Sen. Claire McCaskill joined a bipartisan group of senators Wednesday to announce legislation that aims to reduce the number of sexual assaults on college campuses.

    July 30, 2014

  • An alarming threat to airlines that no one's talking about

    It's been an abysmal year for the flying public. Planes have crashed in bad weather, disappeared over the Indian Ocean and tragically crossed paths with anti-aircraft missiles over Ukraine.

    July 30, 2014

  • Sharknado.jpg Sharknado 2 set to attack viewers tonight

    In the face of another "Sharknado" TV movie (the even-more-inane "Sharknado 2: The Second One," premiering Wednesday night on Syfy), there isn't much for a critic to say except to echo what the characters themselves so frequently scream when confronted by a great white shark spinning toward them in a funnel cloud:
    "LOOK OUT!!"

    July 30, 2014 1 Photo

  • Former Centerville teacher drowns in Creston

    A long-time Centerville Community School District teacher and coach has been identified as the man dive teams recovered from a southeast Iowa lake on Tuesday morning.

    July 30, 2014

  • 20140729-AMX-GIVHAN292.jpg Spanx stretches into new territory with jeans, but promised magic is elusive

    The Spanx empire of stomach-flattening, thigh-slimming, jiggle-reducing foundation garments has expanded to include what the brand promises is the mother of all body-shaping miracles: Spanx jeans.

    July 29, 2014 1 Photo

  • Medical marijuana opponents' most powerful argument is at odds with a mountain of research

    Opponents of marijuana legalization are rapidly losing the battle for hearts and minds. Simply put, the public understands that however you measure the consequences of marijuana use, the drug is significantly less harmful to users and society than tobacco or alcohol.

    July 29, 2014

  • linda-ronstadt.jpg Obama had crush on First Lady of Rock

    Linda Ronstadt remained composed as she walked up to claim her National Medal of Arts at a White House ceremony Monday afternoon.

    July 29, 2014 1 Photo

  • Can black women have it all?

    In a powerful new essay for the National Journal, my friend Michel Martin makes a compelling case for why we need to continue the having-it-all conversation.

    July 29, 2014

  • 0729 OTT Picture veteran -T -M Veteran finally receives his medals OTTUMWA — A World War II injury may have saved the life of a U.S. Coast Guardsman from Iowa, but he lost friends and a box of military awards. Francis Hardy Harbour was born on Dec.16, 1919, in Drakesville. He joined the Coast Guard in 1941 as a mach

    July 29, 2014 1 Photo

Features
AP Video
Dangerous Bacteria Kills One in Florida Visitors Feel Part of the Pack at Wolf Preserve 3 People Killed, Deputies Wounded in NC Shootout Suing Obama: GOP-led House Gives the Go-ahead Obama: 'Blood of Africa Runs Through My Veins' Amid Drought, UCLA Sees Only Water Texas Scientists Study Ebola Virus Smartphone Powered Paper Plane Debuts at Airshow Air Force: Stowaway Triggers Security Review Minnesota Fire Engulfs Home, Two Garages Southern Accent Reduction Class Cancelled in TN Obama Chides House GOP for Pursuing Lawsuit New Bill Aims to Curb Sexual Assault on Campus 3Doodler Bring 3-D Printing to Your Hand Six PA Cops Indicted for Robbing Drug Dealers Officials Unsure of UCLA Flood Repair Date At Least 20 Chikungunya Cases in New Jersey Raw: Obama Eats Ribs in Kansas City Broken Water Main Floods UCLA Raw: Amphibious Landing Practice in Hawaii
Facebook
Hyperlocal Search
Premier Guide
Find a business

Walking Fingers
Maps, Menus, Store hours, Coupons, and more...
Premier Guide
Poll

Upon completion and reopening of Third Street, should the City of Knoxville wait to start the next stage of the Streetscape and Infrastructure project until 2015?

Yes
No
     View Results