Neutron star collision emit light, x-rays, gamma rays and gravity waves. They can directly tell us basic things about stars, the universe, gravity and physics.
What was learned
* the collision event confirmed that gamma rays bursts are from neutron stars merging
* also confirmed was the neutron star mergers generate most of the gold, uranium and platinum in the universe
* this single collision produced an amount of gold greater than the weight of the Earth.
* gravity waves travel at the speed of light
* direct measurement of the hubble constant – initial calculations from the collision suggest the universe is expanding at a rate of 70 kilometers per second per megaparsec.
Future observations of neutron-star mergers will settle more questions
* the internal structure of stars
* the stages and structure of the stars as they merge
* provide more and more accurate measurements of the Hubble constant (the rate of universal expansion)
* neutron-star mergers can test general relativity
* we will learn more about gravity and physics
By 2020, upgrades of LIGO and Virgo will enable one or two neutron star mergers to be detected every month.
Lucky to have the enough of the right tools working
Virgo, a new gravitational-wave observatory similar to LIGO’s two detectors, had just come online in Europe. The three gravitational-wave detectors together were able to triangulate the signal. Had the neutron-star merger occurred a month or two earlier, before Virgo started taking data, the “error box.” or area in the sky that the signal could have come from, would have been so large that follow-up observers would have had little chance of finding anything.
LIGO can only sense neutron-star mergers that occur within 300 million light-years. The GW170817 collision was a relatively close 130 million light years from Earth.
Astronomers waited until sunset in Chile in Aug 17 when they could use an instrument called the Dark Energy Camera mounted on the Victor M. Blanco telescope. It was able to survey a large section of sky. A new Kilonova stood out and was rapidly identified.
Dozens of papers have now been written which describe astrophysical processes that occurred during and after the merger.
Better telescopes and we could be spotting multiple neutron star collisions every day
The Large Synoptic Survey Telescope is currently under construction and will eventually photograph the whole sky every three nights. New instruments will mean that multiple collisions could be spotted every week.
Old telescope data could be re-examined to look for previously detected but unnoticed events.
With the Aug. 17 event, astronomers now know what to look for. Soon, they will be able to sift through many neutron-star mergers and other phenomena.
Astronomy has changed from slow surveys to rapidly spotting and then studying real time collision events.