Once again, the two LIGO and the Advanced Virgo gravity-wave observatories have jointly recorded a cataclysmic event, but this time it’s two neutron stars colliding instead of a pair of black holes—and this time, the event was visible! A paper published yesterday in Physical Review Letters by the LIGO Scientific Collaboration and the Virgo Collaboration titled “GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral” starts out by saying “On August 17, 2017, the LIGO-Virgo detector network observed a gravitational-wave signal from the inspiral of two low-mass compact objects consistent with a binary neutron star (BNS) merger.” Although this new ripple in spacetime was recorded on August 17, it occurred about 130 million years ago. Two seconds after the gravity waves were detected, NASA’s Fermi satellite and ESA’s INTEGRAL satellite both detected a gamma-ray burst from the same direction. Astrophysicists have theorized that neutron-star collisions would produce gamma-ray bursts and the Integral and Fermi observations tend to support that theory.
Using triangulation data from these observations, the LIGO team quickly alerted astronomers around the world and told them where to look. Optical, ground-based observatories were able to image the event visibly and for days after. The Hubble Space Telescope was brought to bear on the event and it captured this image:
Neutron Binary Star Merger Captured by the Hubble Space Telescope
Photo credit: NASA and ESA
This event doesn’t just confirm the gravity-wave observatories’ ability to capture heretofore undetected astronomical phenomena; it has also produced new data that tends to confirm some theoretical models of the universe including the manufacture of heavier elements including silver, gold, platinum, and uranium from the collision. Here’s Dan Kasen, a theoretical physicist at UC Berkeley, to explain this in a riveting 3-minute video:
And why discuss this huge leap in astrophysics in an Xcell Daily blog post? Because Xilinx Spartan FPGAs are incorporated into the design of the gravity-wave observatories and therefore play a role in the discoveries. For more information about this, see: