LIGO's hits just keep on coming.
After its first detection of merging black holes,
swiftly followed by finding 3 more,
and then a Nobel Prize,
the pair of gravitational wave detectors
has made yet another huge discovery.
The observatory detected gravitational waves
from 2 neutron stars spiralling together and merging.
Just 2 seconds later
a so-called gamma-ray burst was detected
by NASA's orbiting Fermi gamma-ray space telescope
and the Swift space telescope.
12 hours after the wave was detected,
a team from Las Campanas Observatory in Chile
reported a new glowing optical source
in galaxy NGC 4 993
--that was consistent with these findings.
And with the advanced tip from LIGO,
radio and x-ray emissions were found a few days later--
coming from the same neighborhood.
Not only is this the first time
LIGO has detected gravitational waves from
a neutron star collision,
it's also the first time that electromagnetic observations
from conventional telescopes
accompany the gravitational waves,
at wavelengths ranging from ultra-short gamma rays
to very long radio waves
the event was seen by observatories
around the world.
Because we now have "visual" information to go
along with the gravitational waves,
new discoveries are being made about the
nature of neutron stars.
The light coming from the collision showed spectral
traces of lanthanides
a group of heavier elements
towards the bottom of the periodic table.
This strongly suggests that merging neutron stars have
been responsible for the creation of heavy elements
such as gold and platinum--
a long-held theory.
Not only that but the shape of the gamma ray burst was
unusually weak.
Gamma-ray bursts are usually so strong that
researchers assume that the gamma rays emerge from
two back-to-back jets, that shoot out
like narrow spotlights.
The weaker gamma-ray burst suggests it was
produced when broader jets slammed into
a cocoon of matter, surrounding the
merged neutron stars.
While this finding is home to a lot of firsts
it won't be the last.
Researchers are positive that
with the large amount of gamma-ray events out there
and the increase in both gravitational
and electromagnetic detector sensitivity
we'll be seeing a lot more of these combination events
in the future.
