Neutron star collision produces gold and platinum
Mon Oct 16, 2017 10:27pm


Burning elements have identification marks in spectrographs of their light. Gold and platinum are detected in the light from an event in NGC 4993, about 130 million light years distant. Read the NY Times article. This isn't "fake news."

(CNN)For the first time, two neutron stars in a nearby galaxy have been observed engaging in a spiral death dance around one another until they collided. What resulted from that collision is being called an "unprecedented" discovery that is ushering in a new era of astronomy, scientists announced Monday.

"We can now fill in a few more tiles in the jigsaw puzzle that is the story of our universe," said Laura Cadonati, deputy spokeswoman for the LIGO Scientific Collaboration and professor in the school of physics at Georgia Tech.

The collision created the first observed instance of a single source emitting ripples in space-time, known as gravitational waves, as well as light, which was released in the form of a two-second gamma ray burst. The collision also created heavy elements such as gold, platinum and lead, scattering them across the universe in a kilonova -- similar to a supernova -- after the initial fireball.

It is being hailed as the first known instance of multi-messenger astrophysics: one source in the universe emitting two kinds of waves, gravitational and electromagnetic.

News conferences were held around the world and a multitude of research papers were published Monday to detail the discovery, which was captured by space and Earth-based telescopes on August 17. These papers and conferences include representatives for the thousands of scientists, 70 observatories and gravitational wave detectors LIGO and Virgo that participated in one of the most-observed and -studied astronomical events of our time. One paper includes thousands of authors making up 35% of the global astronomy community.

Gravitational waves were first directly detected two years ago, proving Albert Einstein's theory of general relativity, and recently, three scientists were awarded the Nobel Prize in Physics for their work on that first detection. Those gravitational waves were the result of two black holes colliding, and the signal lasted for only a fraction of a second. Because black holes don't emit light, these waves were invisible and only "heard" as thumps.

This discovery of two neutron stars colliding to create the same type of waves, in addition to light, allowed astronomers to study gravitational waves in a new way. The signal lasted for 100 seconds, providing them with even more data and insight. It revealed that light and gravitational waves travel at the same speed.

Vicky Kalogera, leading astrophysicist for the LIGO Scientific Collaboration, compared previous detections of gravitational waves to experiencing a thunderstorm in a room with no windows -- only hearing the thunder. This detection was like experiencing a storm in a room with windows, changing everything scientists thought they knew.

Kalogera is also co-founder and the current director of CIERA, the Center for Interdisciplinary Exploration and Research in Astrophysics, an endowed research center at Northwestern University.

'How we made the gravitational wave discovery'
'How we made the gravitational wave discovery'
"The impact for astrophysics is equivalent to the transition from watching a set of still pictures in black and white to sitting in a 3-D-IMAX movie theater: It is a multisensory experience of the universe," Cadonati said.

"Now, we can use this type of event to measure the rate of expansion of the universe," said Marcelle Soares-Santos, assistant professor at Brandeis University and research associate at the Fermilab Center for Particle Astrophysics.