in one of our recent videos we talked
about how a collision between two
neutron stars or a neutron star and a
black hole could be catastrophic for the
entire universe
such an event is called a kilonova or a
macro nova or sometimes an r process
supernova
in 2013 hubble telescope revealed a new
type of stellar explosion produced by
the merger of two compact objects which
were discerned to be either two neutron
stars or a neutron star and a black hole
this was perhaps the first time we
clearly saw the cosmic objects colliding
in a gamma-ray burst
but the first kilonova was quite
possibly observed in 2008
welcome the fact nominal and let's look
at all the images that nasa's hubble
telescope has managed to capture of
kilonovas
[Music]
the images taken by nasa's hubble space
telescope revealed a new type of stellar
explosion produced by the merger of two
compact objects
it was either two neutron stars or a
neutron star and a black hole
the galaxy in the center of the left
image produced the gamma-ray burst whose
lingering effects were visible on june
13th but had faded by july 3.
nasa scientists called the new type of
short but intense cosmic collision and
conflagration a kilonova
that's an explosion so powerful it is
one 000 times stronger than a typical
star explosion called anova
the discovery possibly shed light on the
origin of heavy elements such as gold
and platinum
the wide view of the gamma-ray burst
130603b showed its host galaxy and the
surrounding area and they are nearly 4
billion light years away from the earth
the image shows at least two more
adjacent galaxies making the space gate
look as magnificent as curiosity
inducing it is
however the next pair of the image shows
the galaxy in a close-up focusing on it
exclusively also displaying it before
and after the explosion
gamma-ray bursts are the most intense
outbursts ever detected giving off as
much energy in an instant as our sun
will beam out during its entire 10
billion year lifetime
there are two kinds of gamma-ray bursts
ones that are longer lived lasting more
than two seconds and less common
short-lived ones lasting about 2 seconds
or less
nasa's swift satellite measured
grb130603b
as 0.18 seconds long
while nasa's wind spacecraft determined
that it lasted only 0.09 seconds
nasa's hubble space telescope revealed
that the near infrared afterglow that
accompanied grb130603b
was the kind one would expect from a
kilonova
this is smoking gun evidence that an
explosive merger caused the gamma-ray
burst
however according to nasa scientists the
evidence wasn't enough citing that they
will have to search and study more about
kilonovas to be completely sure
but the 2013 images sure promised a lot
about the kilonova process
on 17 august 2017 the laser
interferometer gravitational wave
observatory ligo and the virgo
interferometer both alerted astronomical
observers all over the globe about the
detection of a gravitational wave event
named gw170817
about two seconds after the detection of
the gravitational wave esa's integral
telescope and nasa's fermi gamma-ray
space telescope observed a short gamma
ray burst in the same direction
in the night following the initial
discovery a fleet of telescopes
commenced their hunt to find the source
of this particular event
astronomers located it in the lenticular
galaxy ngc 4993 that is about 130
million light years away a point of
light was shining where nothing was
visible before and this set off one of
the largest multi-telescopes observing
campaigns ever
but of course the nasa esa hubble space
telescope was among these telescopes as
well
several different teams of scientists
used hubble over the two weeks following
the gravitational wave event alert to
observe ngc 4993
praised the hubble's high resolution
imaging capabilities they managed to get
the first observational proof of a
kilonova
hubble captured images of the galaxy
invisible and infrared light witnessing
a new bright object within ngc 4993 that
was brighter than a nova but fainter
than a supernova
the images you are watching now
displayed that the object faded
noticeably over the next six days of the
hubble observations
using hubble's spectroscopic
capabilities the teams also found
indications of material being ejected by
the kilonova as fast as one-fifth of the
speed of light
in may 2020 a team of scientists
observed what is potentially the
brightest kilonova detected so far
this one was associated with a short
gamma-ray burst labeled grb200522a
hubble space telescope observation
showed that the radiation from this
distant cosmological event didn't fit
the profile scientists had come to
expect from typical kilonova
according to the paper published on the
observed event the infrared light
associated with grb200522a
was significantly more luminous than any
kilonova candidate for which comparable
observations exist
the team was assigned to collect and
combine observations from the hubble the
very large array the las cumbres
observatory global telescope and the wm
keck observatory was led by wen phi fong
she stated that hubble was the deciding
factor as it was the only telescope to
detect infrared light
amazingly hubble was able to take an
image only three days after the burst
hubble's spectacular resolution was also
key in quantifying the amount of light
coming from the merger
the hubble observations were designed to
search for infrared emissions that
resulted from the creation of heavy
elements like gold platinum and uranium
during a neutron star collision
to the team's surprise they found a much
brighter infrared emission than anything
anybody had expected
the reading indicated that there was an
additional energy input from perhaps a
magnetar
magnetars are neutron stars that have an
insanely super strong magnetic field
clearly this magnetar was the remnant of
the observed merger
according to a co-author on the team the
kilonova discovered in 2020 outshines
the one discovered in 2017 by miles
it was astounding for the team because
most of them had been studying this
phenomenon for more than 10 years and
yet the very first one they discovered
left them feeling like they know very
little
this information made grb200522a
different from all other potential
kilinovae because given what scientists
know about the radio and x-ray emissions
from this particular blast
numbers were not matching up
hubble's read on the infrared emissions
was over the roof with brightness
simply there was a piece in this puzzle
that didn't mean to go with the rest of
the picture
according to fong these observations do
not fit traditional explanations for
short gamma-ray bursts
in order to understand the exact levels
of brightness and the distance of the
origin the team used wm keck observatory
on mauna kea in hawaii
in such cases distances are important in
calculating the burst's true brightness
as opposed to its apparent brightness as
seen from earth
it is kind of similar to how the
brightness of a light bulb depends on
both its luminosity and its distance
from the eye for how much time it will
take to reach it
a gamma ray burst could be really bright
because either it is intrinsically
luminous and distant or not as luminous
but much closer to the earth
thanks to the keck observatory the team
was able to determine the true
brightness of the burst and thus the
energy scale
they found that this kilonova was much
more energetic than they originally
determined
the biggest mystery that is intriguing
scientists fraternity is what is left
behind in such a collision
could it be a more massive neutron star
or perhaps a newborn black hole the fact
that we see this infrared emission and
that it is so bright shows that short
gamma-ray bursts indeed form from
neutron star collisions but surprisingly
the aftermath of the collision may not
be a black hole but rather likely a
magnetar
however unlike 2017 this kilonova didn't
give us a splash of gravity waves so the
magnetar theory definitely needs more
evidence
a magnetar is part of the neutron star
family as it is an ultra dense star with
a magnetic field stronger than earth's
by a trillion times
magnetars are sadly short-lived well at
least by cosmic standards with an age of
perhaps 10 000 years only that could be
very well defined as ephemeral when it
comes to star life spans
but they are probably the best source of
fast radio bursts aka frbs
hopefully follow-up observations in
radio a few years down the line we'll be
able to confirm whether there is indeed
a magnetar behind this unexpectedly
bright observation
and with james webb telescope's launch
things are going to be way brighter in
the future for space exploration
tell us in the comments how excited you
are for the webb telescope and the human
presence in space and once again thanks
for watching fact nominal