Hi, I'm Alex Mccoan and you're watching
Astramm. Hubble has released the zip
file on their website containing the top
100 pictures Hubble has ever taken. What
I will do over the course of this series
is go through these pictures one by one
and explain what it is you're looking
at. And believe me, some of these
pictures require an explanation.
Number 22, NGC 4449.
At first glance, I thought this was one
of the magnanic clouds, but it's
actually a small irregular galaxy in a
galaxy group called Keen Venatasai about
12 million light-years away.
This means like us, it is part of the
Virgo supercluster, otherwise known as
the local supercluster of galaxies.
It is similar to the large magnanic
cloud in that it has a general bar
shape. But the big difference is this is
considered a starburst galaxy. It is
very active in producing new stars as
can be seen here in these pinkish
regions. Pink or red areas in a galaxy
are generally a telltale sign of star
formation as stars surrounded by
hydrogen gas ionize the hydrogen to glow
red with intense radiation.
Another telltale sign of high rates of
star formation is the many blue stars
you see in this picture.
Blue stars are extremely hot, young, and
often massive stars that will burn out
quickly because they get through their
fuel so fast. Because these stars can
only live to a certain age, they must
have only been produced within the last
few million years. And as we can see,
there are many blue star clusters in
this galaxy.
This starburst is thought to be because
of galaxies interacting with NGC 4449.
If we zoom out a bit, we can see this
trail of red stars. Perhaps the remains
of a spheroid galaxy passing through NGC
4449. And it's stretched by this tidal
effect.
Looking at the galaxy center, we see a
bright white group of stars with some
dark clouds of dust around it. Stars can
form within clouds like these.
This galaxy is 19,000 lighty years
across.
Number 23, HD97950.
This spectacular superstar cluster is
found within NGC 363,
an H2 nebula.
It is incredibly pretty and has been
studied a lot because it's found in the
Karina spiral arm of the Milky Way
roughly 20,000 lighty years away.
NGC 3630
is interesting to astronomers because it
is the most massive visible cloud of
glowing gas and plasma known as an H2
region in the Milky Way. And the
superstar cluster has the densest
concentration of stars known in our
galaxy. The UV radiation and stellar
winds have carved into this surrounding
dust, producing these beautiful shapes,
but also given us an unobscured view of
the superstar cluster. Stars of note in
this cluster are share 25, a star 60
times the mass of our sun and reaching
the end of its life cycle. It's expected
to go supernova any time now as it's
already thrown off matter in a similar
manner to what has been seen in other
supernova.
We also have the three main stars in the
heart of the cluster, barely
distinguishable in the center of these
images here. All three are wolf ray
stars, each about 100 times the mass of
the sun and millions of times more
luminous.
Two of them are incredibly close
together as part of a binary star
system, taking only 3.5 days to orbit
one another.
This means they are practically
touching, no doubt exchanging a lot of
mass as well as having an incredible
tidal influence on each other. Zooming
out a bit, we see that visually NGC 3630
is right next to another nebula, NGC
3576.
But in actual fact, this other nebula is
much closer, only about half the
distance to us. They just so happen to
be visually aligned.
Number 24, Messia 74.
On first glance at this image, I thought
it was another viewpoint on the famous
galaxy we've already looked at, the
Whirlpool Galaxy.
When putting them side by side, these
galaxies do look remarkably similar.
They are both grand design spiral
galaxies for a start and have similar
dust patterns weaving through their
arms.
But putting them side by side, you can
tell that there are slight variations in
these two galaxies. M74's arms are lined
with hot blue stars with pink and red
star forming regions dotted all over.
You may think the arms of the galaxies
like this are static arms rotating
around the nucleus of the galaxy, but
actually they are the visual effect of
density waves. As gas and dust orbits
the galaxy, they pass through the
galaxy's density waves, which compresses
the gas and dust and causes stars to
form. Existing orbiting stars also clump
up in these density waves.
A lot of these stars will be blue and
only short-lived, perhaps completing
their life cycle in only a few million
years.
M74 is about 32 million lighty years
away and has a low surface brightness,
making it one of the most difficult
messier objects for amateur astronomers
to observe and given it the nickname the
phantom galaxy. It is probably just a
little smaller than our own Milky Way
galaxy, containing about 100 billion
stars and being 95,000 lightyear across.
It sits in the M74 group, a small little
remote group of galaxies.
Number 25, AR48.
So, first impressions, what do you think
this could be? Pause the video and take
a guess in the comments if you want.
Well, this bizarre shape found a
staggering 500 million lighty years away
is a galaxy and is nicknamed males
object. It is in fact most likely to be
two merging galaxies. The initial
collision theorized to have created a
shock wave which drew matter into the
center before it propagated out into
this ring. You see the tail is a
streamer of stars from one of the
galaxies, further suggesting this is an
ongoing collision. Interestingly, and on
a little side note, the ARP catalog is
the Atlas of peculiar galaxies.
Number 26, Able 2218.
Now, if you thought the last image was
an impressive distance away, have a look
at this one. Able 2218 is an impressive
cluster of galaxies 2.1 billion lighty
years away. Clusters like these are
particularly scientifically interesting
because these galaxies immense gravity
bends the light around them acting as a
magnifying glass to see galaxies even
further behind them. These long arcs you
see in the image are actually distant
galaxies light stretched and warped by
the gravity of the nearer galaxy
cluster.
In this image is perhaps the most
distant galaxy known at an estimated 13
billion light years away. In this image
is barely visible but in an enhanced
version we can make out its stretched
appearance. Because of this lensing
effect, the galaxy appears twice in this
image. Here as well as here,
we see it from Earth as it was only 750
million years after the Big Bang,
meaning we're looking back in time to
really the early universe.
There are around 10,000 galaxies in this
image.
Number 27, Able 1703.
This is another galaxy cluster doing the
same lensing effect we looked at in the
previous image. I want to explain in a
little more detail about how this
lensing effect works. Firstly, we look
at a distant massive object. Gravity is
theorized to warp spaceime. Perhaps a
topic I'll come to in another video. But
often elliptical galaxies are the
biggest galaxies in existence. And the
more massive the galaxy, the bigger the
warping effect on spacetime. You can see
this with the lensing effect around the
big elliptical galaxy in the middle of
this image. As spacetime is warped,
light is bent around the galaxy. And if
it's aligned right, it gives us a
magnified view of the other side of the
galaxy.
It's a natural handy magnifying glass
just floating in space. And about this
galaxy cluster, AEL 1703 is around 3
billion lighty years away.
So without further ado, here's number 29
of the series, NGC6960
or the Veil Nebula.
This astonishingly colored web of
filaments is in fact a small portion of
the Witch's Broom Nebula, which in turn
is part of the huge nearby nebula known
as Signis Loop. Signis Loop is only
1,500 lighty years away from us, very
close by astronomical standards. It is a
giant supernova remnant or the remains
of a dead star that exploded about
10,000 years ago. Since then, it has
expanded to cover an area that is as
wide as six full moons in the night sky.
Sadly though, this nebula is also quite
faint and is not visible with the naked
eye.
As always with Hubble images, the bright
colors here are representative of the
ionized atoms in the image. Blue is
oxygen, green is sulfur, and red is
hydrogen. The ionization of the atoms
comes from the shock wave of the
supernova, blasting debris 600,000 kmh
into surrounding gas, heating it to
millions of degrees.
As this gas cools, it releases
wavelengths of light that are then
picked up by Hubble.
To me, this nebula is a masterpiece. I'm
not one to be able to analyze art.
Perhaps some of you can do better in the
comments, but the colors are just so
vibrant and the filaments are so
intricate. I'm just blown away by this
image.
Number 30, NGC1275.
Now, this is a really odd looking
galaxy.
I'm much more used to seeing pretty
bands in a spiral galaxy, or at least
galaxies that are somewhat symmetrical.
These filamentary structures here though
are just randomly going wherever they
please, seemingly disconnected from
their parent galaxy. Well, it seems
disconnected because this part of the
image here is in fact a separate galaxy
roughly 200,000 lightyear in front of
the larger background galaxy. The
smaller galaxy is known as a high
velocity system, speeding towards the
background galaxy at 3,000 km a second.
At one point in the future, there's
going to be an almighty collision
between the two.
Going back to the filaments, scientists
are puzzled as to why and how they exist
without either warming up, dissipating,
or forming stars.
It's thought this can only be due to the
super massive black hole at the center
of the galaxy. A monster black hole at
800 million solar masses. The black hole
may be able to suspend the gas in the
filaments using its huge magnetic field
which according to models have survived
for 100 million years. The galaxy itself
is massive, one of the biggest types
that we know of. This image is about
260,000
lightyears across and NGC1275
is found 237 million lighty years away.
Number 31. I see 2497
or honey's for
the galaxy itself looks normal enough,
but what's all this green at the bottom
of the image? Now, this explanation is
seriously bizarre. The green blobs or
Han's forbear, which means Han's object
in Dutch, is the visible part of a gas
streamer that stretches 300,000 light
years around the galaxy. I say visible
part because what is thought to be a
flashlight beam of light from the
galaxy's core has illuminated this
section. This flashlight is thought to
have come from a quazar, a first for
this series. Very basically, a quazar is
a super massive black hole that is
emitting an absolutely huge amount of
electromagnetic radiation in all the
different wavelengths. We're talking 10
^ 41 watt, thousands of times greater
than the whole Milky Way combined.
In this image, it is theorized that a
smaller galaxy bumped into IC2497,
causing a lot of gas to fall into its
super massive black hole. This sudden
increase in gas falling into the black
hole causes it to turn on as a quazar,
emitting a beam of light like cone onto
Han's for gas also streams away from the
parent galaxy, impacting Han's for
triggering star formation. This star
formation is actually why the tips of
this gas cloud are a different color.
The gas itself is green because in this
image it is ionized oxygen atoms.
The quazar has since shut down so it's
not visible anymore but the light is
still reflecting off Hanis Warv as we
speak. The quazar is the closest one
that we know of although it is still 730
million lighty years away. The most
active one is 1.7 billion lighty years
away.
Number 31. And oh wow. This is the Twin
Jet Nebula or PN M29.
And although I've seen this image lots
in the research for this video, I'm
still amazed that there is something
like this in space right now.
This is a planetary nebula and it is the
result of what happens when one star in
a binary star system ejects its outer
shell.
Astronomers theorize that the gravity of
one star pulls some of the gas from the
surface of the other and flings it into
a thin dense disc extending into space.
This time-lapse sequence shows a jet
move within the structure over the
course of several years.
It's this jet which is thought to give
the nebula its shape. The star which
ejected its shell is now a cooling off
red giant which eventually will become a
white dwarf.
The twin jet nebula is about 2,100
lighty years away from us.
Number 32 is a giant space bubble known
as NGC 7635.
To me, this looks like a giant marble
many light years across.
Somehow, you just don't expect to find
bubbles in space, but here is one, and
it is gorgeous.
The area is known as an H2 region or a
star forming area. This whole nebula
around the bubble is in fact a molecular
cloud, which is cold gas and dust. The
bubble itself is caused by stellar wind
from this massive and hot star in the
center of the bubble pushing the gas and
dust in the nebula away from the star.
But the molecular cloud is resisting
with its own internal pressure. What we
are witnessing here is a pushing contest
between the molecular cloud and the
stellar wind. The edge of the bubble is
ionized atoms of the cloud, the front
line of where this battle is taking
place. Put into this perspective, the
star is trying to free itself from the
nebula by blasting it away.
In a few million years, we will see what
becomes of this battle.
NGC7635
is about 10,000 lighty years away.
Number 33, and we are coming to an
exceptionally oddlooking galaxy called
NGC1512.
Now, this image is really pixelated
because I've zoomed in a lot. But this
looks like it could be the whole galaxy,
right? Well, it's not. Zooming out
reveals this is not the only part of the
galaxy. It's got another outer ring all
the way out here. This by itself looks
weird enough. You have a halo of stars
around the inner ring, which dims the
further you go out to this outer ring.
They also have these two bars of dust
seemingly connecting the rings together.
And it looks like a giant eyeball. But
wait, there's more.
There's a neighbor galaxy called NGC1510
right here next to it. Or is it next to
it? Zooming out again reveals we are
still only looking at half of NGC1512
in that last image. It is crazy. The
galaxy has another section of spiral
arms outside of the outer ring, which
means the smaller galaxy is actually
within the bigger one, and they are
really in the process of merging. This
has been going on for 400 million years
already, and explains why the outer arms
are so extended, and why the galaxy
looks as weird as it does.
Eventually, the smaller galaxy will
merge with the bigger one and they will
become one. NGC512
is about 39 million lighty years away
from us.
Number 34 and the last image for this
episode. Now, what do you think this
could be? The birth of a star, maybe?
Well, while it's not known with
certainty, it is thought this
spectacular image is in fact a star
shortly before it ejects its outermost
shell into a planetary nebula. What we
are looking at here is the egg nebula or
a protolanetary nebula. This stage of a
star's life is short, only lasting for a
few thousand years. Plus, it's very dim,
which means there are only a few of them
that we know of.
What you will notice is this disc of
dust surrounding the central star. And
where there are gaps in the disc, the
star shines through like spotlights
illuminating the nebula.
The onion layers in the surrounding
nebula are thought to be parts of the
outer layer of the dying star that have
been ejected every couple of hundred
years.
The nebula's layers only reach out for a
tenth of a light year. So, this object
really is small. The Egg Nebula is found
2,000 lighty years away.
This is Andromeda,
our closest galactic neighbor.
So many stars.
It's like sand in the sea.
But just think,
every single one of these dots is a
giant star.
Individually visible to us 2 and a half
million lighty years away.
Each star likely has its own planets,
comets, asteroids,
its own story.
The Hubble Space Telescope has just
created the most indepth and complete
image we have ever seen of the Andromeda
galaxy.
And we're seeing it in a new light.
A light so brilliant and bright that by
the time we get to the galactic nucleus,
the stars are so densely packed together
that they appear like a brilliant solid
golden glow.
This is no gentle spiral in the night
sky.
Andromeda is home to violence,
a place whose presence has cataclysmic
consequences for those nearby. including
us.
I'm Alex Mccoan and you're watching
Astramm.
Join me today as we take a trip next
door to the Andromeda galaxy and explore
arguably the most impressive image of
another galaxy ever taken, including 200
million of its stars. We'll show how
Hubble's groundbreaking new portrait is
being used to piece together Andromeda's
turbulent past and predict what violence
might be on the cards in its future.
We've been observing Andromeda for more
than a thousand years. It was first
spotted in 964 AD by Persian astronomer
Abdul Rayman, who described what he saw
as a nebulous smear. We didn't really
get a better look than that until nearly
700 years later when on the 15th of
December 1612, Simon Marius became the
first ever person to observe the
Andromeda galaxy through a telescope.
Slowly but surely, more details of this
seemingly fuzzy nebula emerged. Charles
Messier officially classified it M31 in
1764.
But one of the most important
breakthroughs came 100 years later. The
third Earl of Ross, William Parsons, was
a keen yet eccentric amateur astronomer.
He had the massive 72in Leviathan of
Parson'stown telescope built in the
garden of his Burr Castle in Ireland. It
remained the largest telescope in the
world for some 70 years. Parsons used
this beast of a scope to spot the spiral
structure of a nebula named M51,
or as it's known to most of us, the
Whirlpool Galaxy. It was the first time
a spiral structure had ever been seen in
a nebula and the discovery sparked a
flurry of interest from astronomers of
the time. As they turned their attention
to other nebula, it resulted in the
first ever photograph of the Andromeda
galaxy taken by amateur British
astronomer Isaac Roberts in 1888.
And that photo, as you can see, shows a
clear spiral structure.
Even with this photographic evidence,
scientists weren't sure what Andromeda
was. But they classified it alongside
thousands of other spiral nebula that
all had something else in common. They
didn't move like the rest of the stars
in the night sky do. This realization
inspired one of the major debates among
astronomers in the late 19th century.
Were spiral nebula part of our own Milky
Way galaxy? or could there possibly be
other island universes beyond?
In 1925, Edwin Hubble resolved the
issue. Hubble identified two seared
variables in the Andromeda Nebula known
as standard candles. These variable
stars can be used to measure galactic
distances thanks to the correlation
between their period and luminosity.
Hubble calculated that these seafoods
were about 1 million lighty years away.
Far too far for them to lie within the
bounds of the Milky Way, which at the
time was estimated to be no wider than
300,000 lighty years across.
Since Hubble's discovery that the
universe extends beyond the Milky Way,
we've discovered countless galaxies. But
we still share a special relationship
with the one that opened our eyes to the
vastness of space, our cosmological
nextoor neighbor. Andromeda has arguably
taught us more about how galaxies work
than even our own. You see, it's tricky
to study galactic structure in the Milky
Way because we're inside it. There's
quite a lot of stuff to get in the way.
Interstellar dust can scatter light so
that objects look redder than they
should. It's tricky to measure accurate
distances and sometimes details are
blocked by noise in the foreground.
Andromeda or M31, however, doesn't have
many of these issues. At around 2.5
million lighty years away, it's a place
where we can study galaxy formation and
evolution relatively unimpeded.
But to make the best use of this
laboratory, we need clear images.
Experts and amateurs, groundbased and
space telescopes have all taken a look
at Andromeda from a number of different
angles, resolutions, and wavelengths.
But on the 16th of January, 2025, the
Hubble Space Telescope released an image
that put all our previous efforts to
shame. After 10 painstaking years of
observing Andromeda, it has created the
largest photo mosaic ever assembled.
Taken over 1,000 Hubble orbits, it
encompasses more than 600 snapshots and
2.5 billion pixels. The result is the
most in-depth and complete view of
Andromeda we have ever seen. So without
further ado, let's take a look.
This image shows Andromeda nearly edge
on, tilted 77° relative to our view from
Earth. In it, you can see the northern
region to the right and the southern
region to the left. Astronomers predict
that Andromeda could be home to as many
as 1 trillion stars, but most are too
dim to be detected even by a powerful
telescope like Hubble. Nevertheless, it
was able to resolve a whopping 200
million stars, making it the most
detailed image ever taken of any galaxy
anywhere in the universe. With such a
stunning census of our closest neighbor,
scientists have been able to reveal more
about its history, how it compares to
our own cosmic home, and how it may
evolve in the future.
We know Andromeda is a spiral galaxy
measuring around 150,000 light-years
across with arms that extend out from
its nucleus across the sky. Despite this
classification, many of its features are
pretty unusual. And thanks to this new
image, we are starting to understand
why.
Created in 2015 with the conclusion of
the FAT program or pancromatic Hubble
Andromeda Treasury, this image is highly
zoomable, and so it should be. Hubble
spent more than three years
photographing a third of Andromeda's
star forming disc. These images were
taken across six spectral bands ranging
from near ultraviolet to near infrared.
If you take a look at the outer region,
you can see an elliptical ring of star
formation found roughly 10 kiloparex
from Andromeda's nucleus. These newborn
stars are bluer and therefore hotter
than most other stars in this region.
They are also metalrich, meaning they
contain elements heavier than helium or
hydrogen. The more you zoom in, the more
of these individual stars appear. There
are so many. The Hubble team say they
look like grains of sand on a beach. The
resolution is truly that good. This ring
of star formation puzzled astronomers.
And it wasn't the only thing. Using
images taken by the infrared array
camera on the Spitzer Space Telescope in
2006, researchers found a second inner
dust ring situated about half a kiloparc
from Andromeda center. This one was
hiding in plain sight. Initially,
scientists had assumed it was a mini
spiral related to dense regions of
overlapping stellar orbits. Two rings
meant that what scientists were seeing
couldn't just be an anomaly. But where
did they come from? These rings were
about to unlock Andromeda's past.
For decades, scientists had looked at
the galaxy and found little evidence to
suggest a violent history. But these
rings showed a different story. As
astronomer and author of the 2006 study,
David Block put it, "These dust rings
are like ripples in a pond." And where
do ripples come from? A point of impact.
That's right. Scientists concluded the
rings were the remnants of a collision
between Andromeda and one of its
companion galaxies around 210 million
years ago. Just like a stone being
dropped into a pond, the impact between
Andromeda and this other galaxy produced
shock waves of dust that radiated
through the disc, leaving behind two
ghostly trails we can still observe
today.
Block and his colleagues blame dwarf
galaxy Messia 32 for this impact. Today
it appears as a bright fuzzy haze of
stars found just 5 kiloparex from
Andromeda's center. When they ran
numerical simulations to recreate the
impact, the authors found that a headon
collision was able to reproduce the
rings we see today. There is a
conspicuous hole in the outer ring that
was formed when it interlaced with
Andromeda spiral. And the simulations
were even able to recreate this feature.
Since that discovery in 2006, many
thought that we had revealed the extent
of our galactic neighbors trauma. But
thanks to Hubble, Andromeda was about to
give up more of its secrets.
You see, the 2025 image of Andromeda was
made from the combined efforts of not
only the fat survey, but also the fast
survey. This extended the original
program to photograph Andromeda's
southern region and ran from 2021 to
2024. FAST added a further 90 million
stars to the census and expanded its
scope to cover 2/3 of the galaxy's star
forming disc. The need for this southern
focus survey was born out of the
realization that Andromeda's polar
regions are almost nothing alike. The
southern region appears to be far more
disturbed than the north and therefore
carries more evidence of Andromeda's
violent history, and there's plenty of
battle scars to find. You can't really
make it out in the Hubble image because
it's too dim, but the giant southern
stream is a mammoth feature of Andromeda
that spans around 150 kiloparex from the
galaxy's southern disc into the halo.
You can think of it as a stream of
debris from a galaxy that was stripped
of its stars by Andromeda's gravity. The
GSS is dissipationless,
meaning the stars in it are cold and
hold no significant amount of gas. Their
paths are still dictated by
gravitational forces, but they don't
radiate heat or collide with other stars
in the stream. It's like a group of
marbles rolling down separate
frictionless tracks. The GSS along with
M32 and the inner halo are three of the
most prominent metalrich features found
in Andromeda. For some astronomers,
their shared metallicity suggests they
are all products of another major
collision event in Andromeda's history,
even larger than the one that produced
the rings. But this event has a familiar
antagonist.
A study in 2018 sought to investigate
this bigger collision and put the
spotlight back on M32.
Well, M32's ancestor. Cosmological
simulations named Andromeda's most
likely victim as an earlier version of
M32 named M32P.
In its heyday, this ancient metalrich
galaxy had a mass of 25 billion suns and
merged with Andromeda between five and
two billion years ago. Its gas would
have been vacuumed up by the greater
force of Andromeda's gravity, triggering
a burst of star formation, which created
about a fifth of the stars we see in our
galactic neighbor today. And what's
more, we think we know which ones they
are. Andromeda contains several billion
stars that are of intermediate age. And
astronomers had been struggling for
years to explain why. They expected
Andromeda's stellar population to look
more like that of our Milky Way,
distinct regions of much older stars in
the Bulge and Halo and younger stars in
the thin disc. However, if these
middle-age stars formed during the
merger with M32P,
then we finally have an answer for where
Andromeda's second wind of star
formation came from. For more proof, we
just have to look at M32 in Hubble's new
image. If we go with the theory, then
what we are seeing is the stripped core
of M32P.
And that description seems to fit. M32
has a central black hole with a
relatively low mass between 1.8 and 5
million solar masses. And astronomers
can use this to work out how big its
central bulge might have been before it
merged with Andromeda. These
calculations show that M32P's central
bulge was small, which explains why the
galaxy did not sink completely into the
center of Andromeda during the merger.
Instead, the stripped core was able to
survive on the outskirts of the galaxy,
where it remains to this day. As I said,
this is still a theory, but it appears
to answer a lot of questions about
Andromeda's troubled past and unites
several of its most unusual features
together. But things might still be more
complicated than that.
Andromeda has 36 different dwarf
galaxies surrounding it. And any one of
these galaxies may have interacted with
it in the past. It's only now that we
have such a highresolution view of our
neighbor, thanks Hubble, that we can
start to look for signs of smallcale
interactions with it satellites. Who
knows what we'll find?
But it's not all about the past. This
spectacular image can also tell us about
the future. our future.
As the two biggest gravitationally bound
members of the local group, Andromeda
and the Milky Way are often thought to
be the most likely candidates for a
collision. It was estimated in 2012 that
Andromeda is falling towards our home
galaxy at a rate of 110 km/s
and will hit in about 4 billion years.
Of course, this is probably not a threat
that the human race will ever have to
worry about. But it's fascinating to
think about how these two beloved
galaxies could change if a collision
ever comes to light. But before you
start imagining what Milkomeda would
look like, it's important to highlight
that this is still a debate. Thanks to
the new image from Hubble, we have
reason to believe that our galaxy could
live to fight another day. In a paper
published this year, Till Savala from
the University of Helsinki and his
colleagues used the Hubble data on
Andromeda to refine the models of the
local group. Specifically, the FAT
survey measured distances to 55 seafids
within Andromeda. These combined with
the orbit of other local group galaxies
like the large melanic cloud showed that
the fate of our galaxy was much more
uncertain with only a 50% chance of a
merger with Andromeda in the next 10
billion years. Predicting what will
happen to our galactic neighborhood in
billions of years is no mean feat, but
it will be much easier now that we can
see its current state so clearly.
The 10-year endeavor of the fat and fast
programs has now come to an end. But the
work doesn't stop there. With enough
detail to cover 75 8K ultra
highdefinition screens, scientists are
nowhere near done finding the secrets
hidden within this image. And it's just
one of a seemingly neverending stream of
clues. Hubble may have turned its
attention somewhere else for now, but in
June this year, more images were
released from the Shandra X-ray
Observatory, showing Andromeda's super
massive black hole in unprecedented
detail. With each observation adding
ever more detail, the story of Andromeda
will become even more complete over the
next few years. And so far, it's shaping
up to be a good one. I can't wait to see
what Hubble's scientists piece together
next. But in the meantime, I hope this
video has brought you closer to
Andromeda. After all, we are neighbors
and we could be getting a lot closer in
a few billion years.
Light may seem instantaneous to us, but
over astronomical distances, it's really
quite slow. RS Papus is a variable star
tucked into a nebula. And being a
variable star means it pulsates in
brightness over time. In this case, 41
days. And incredibly, because light is
so slow over these vast distances, you
can watch the light move through the
surrounding nebula in what is called a
light echo. Every time the star peaks
and dips in brightness, you'll see a new
crest of light move away from the star
through the nebula. This is a real
Hubble time lapse taken over several
weeks. This is not CGI.
Number 21, the Karina Nebula.
It hardly needs to be said, but this is
a gorgeous image. It looks to me like an
artist has flick painted the canvas in a
spectacular way. But incredibly, the
colors and shapes we see are actually
representative of something real. Now,
hold on to your seats because it's the
only image we're going to look at today.
There's simply too much to talk about,
and I don't want to have to cut out any
interesting details, which is good for
me and for you. So, to start off, where
is it? The Karina Nebula is actually
brighter and bigger at 200 lightyears
across than the famous Orion Nebula we
discussed in the previous episode, but
it isn't as well known. This is because
it's only visible from the southern
hemisphere, meaning us up north won't be
able to see it in the sky. It's found
near the Kina constellation and is in
the disc of the Milky Way galaxy. is
only 6,500 light-years away from Earth,
yet can be seen with surprising clarity
with a long exposure camera or a small
telescope.
What we're seeing in this image is like
the other nebula we've seen so far, the
effects of extremely hot, young, massive
stars blasting away at the dust and gas
of the nebula. This, as we know,
encourages star formation. And this
nebula has plenty of star forming
regions. Just off this main image here
is the most luminous star in the Milky
Way, WR25.
Thankfully, it's easy to find because
this dust structure known as the finger
of God is pointing at it.
It's a staggering 6.3 million times more
luminous than our sun. It's part of a
binary star system, but the two stars
can't be distinguished in this image. We
have to zoom in further to see them. The
companion is thought to contribute about
15% WR25's total luminosity.
It is absolutely blasting away at this
nebula.
The Finger and surrounding globules are
being evaporated into space, possibly
even causing star formation there, too.
Even though it's reasonably close to us
and is the brightest star in the galaxy,
can't actually be seen with the naked
eye. There's too much dust and gas
deflecting and absorbing its light. This
image we're looking at included infrared
data, which can see through dust and gas
a lot easier than visible light.
The colors of this image are
significant, too. Red represents sulfur,
green is hydrogen, and blue is oxygen.
This whole region of stars is the star
cluster known as Trumpus 16. Also
contained within this cluster is the
massive and famous Eta Karina. Although
not quite as bright as WR25, it's still
over 4 million times more luminous than
our sun and over 100 times more massive.
It again is part of a binary star
system. The other star making total
luminosity over 5 million times that of
the sun. Now imagine the sun and then
imagine it 5 million times brighter.
If you're doing it right, what you
should be doing is imagining instantly
and spontaneously combusting.
Let's see why. So, this is a
hypothetical but similar binary star
system. And this is a hypothetical
planet which is a little further away
than what Neptune is to our sun. Its
surface temperature is 500° centigrade.
On Neptune, it's -200.
The sun looks tiny in comparison and
Neptune really is this dim.
So Eta Karina is pretty impressive then.
It is a luminous blue variable star
meaning its brightness is changing over
time. Only 150 years ago it was the
second brightest star in our sky before
fading to below naked eye visibility.
The reason for this is because the star
almost went supernova.
This image of the star is the most
detailed and highest resolution of an
extended object ever captured by Hubble.
Structures only 10 billion km across can
be seen with surprising clarity. What
we're looking at here is the ejected
mass of the star when it brightened 150
years ago. It actually got as bright as
a supernova explosion, but somehow
survived. During the explosion though,
it did release mass in the form of two
polar loes and an equatoral disc, all
moving outward at a speed of 2 million
km an hour.
Since the explosion 150 years ago, it
has increased in brightness and is now
comfortably visible to the naked eye.
Chances are it will still go supernova
as it really is at the end of its life
and could do so at any moment. Now there
are three possibilities of the fate of
this star. First is it can go supernova
in a typical manner where its core
collapses and it would temporarily
appear as bright as Venus in the sky.
It could also go hypernova potentially
being the brightest supernova in
recorded history and a long duration
gammaray burst would knock out all of
the satellites in our space. Although we
humans with our feet firmly on Earth
would be protected by the atmosphere.
The last and most unlikely possibility
is that it collapses into a black hole.
Now fun/horrifying fact if it did that
and one of ETA Karina's polar axis was
aimed at Earth collapsing into a black
hole would likely give off a gammaray
burst which would strike the Earth's
atmosphere.
This would be the equivalent to 1
kiloton of TNT per square kilometer over
the entire hemisphere facing the star.
Effectively meaning the end of the
world. Don't worry though, its axis
isn't currently facing us and it's not
really expected to give off a gammaray
burst. But it is food for thought
nonetheless.
Near etc is the keyhole nebula. A
structure of dark cool gas and dust and
also bright fluorescent gas. Etcarina
has a big effect on the nebula ionizing
gas and pushing against the surrounding
dust.
These bubbles and lines you see are due
to the effects of this star.
Also in the Karina Nebula is the famous
Mystic Mountain, which you've probably
seen before, and it is an image we'll
discuss later in this series. To me,
though, it looks more like a man with a
wizard's hat going on a leisurely
stroll, but maybe that's just me.
The last thing we'll look at today is
Trump 14, the other big star cluster in
this image. It's one of the youngest
known clusters, and it contains about
2,000 stars. They are thought to be only
300 to 500,000 years old, which is very
young for astronomical standards.
They're extremely hot and will only be
short-lived. They will likely dissipate
in the next few hundred million years,
so enjoy them while you can.
The Hubble Space Telescope has been in
operation for an astonishing 28 years,
and during this time, it has imaged some
spectacular sights of our galaxy and
beyond.
It is truly a marvel of technology and
has helped us improve our knowledge of
the universe we live in to no end. This
includes understanding the many
different types of stars in our galaxy
in various stages of their development.
In this episode, we are going to have a
look at some of the most special and
peculiar stars it has seen. And believe
me when I say that some of these are
simply breathtaking.
Number 35, HH34.
This amazing site found near the Orion
Nebula is a Herbig Harrow object or an
emission jet from an extremely young
star that is still in the earliest
stages of its formation. You can see the
star here still tucked inside this
molecular cloud.
The Orion Nebula is one of the closest
H2 nebula or star forming region to us,
which means we can see stars in the
process of being formed reasonably close
up.
The star is releasing this extremely hot
jet of gas from one of its poles, which
speeds through space at hundreds to
thousands of kilometers/ second.
Eventually, this jet hits colder
material, heating it up, which is what
you can see here at the bottom left.
For astronomical standards, this is a
very short-lived event, only lasting a
few thousand years.
Number 36. More stars in the process of
being formed. This is XZ Tori and its
neighbor stars HL Tori and V1213
Tori. To me, this image is one of the
most mindblowing images Hubble has ever
taken. The birth of stars taken against
this backdrop of a dark molecular cloud.
Let's have a look at what's going on.
This is XZ Tori, a star system
containing two stars about the distance
of our sun and Pluto apart.
For reasons unknown to scientists, these
stars have ejected a huge bubble of hot
gas seen here. This bubble is expanding
at a rapid rate as seen over the course
of 5 years.
This over here is HL Tori. Another very
young Tori star. This star has a
protolanetary disc surrounding it,
meaning planets are likely still in the
process of forming here.
It's also ejecting another herb big
harrow object number 150 shooting over
in this direction.
And finally, we find V1213
Tori, a variable star with a spectacular
disc surrounding it. At a sideon angle
to us, the disc obscures the view of the
star itself,
but its reflected light comes off the
surrounding gases and HH30, the hair big
harrow object shooting off in both
directions away from the star.
An amazing image found near the Taurus
constellation
number 37. Okay, just one more protoar
HH24.
The star itself is again hidden away by
the blanket of the molecular cloud it is
surrounded and being fed by. But what is
clearly evident is the lightsaberlike
jet of gas being blasted away from the
star in both directions.
It shares a lot of similarities to the
other herbic harrow objects in this
episode, but the image itself is so
impressive nonetheless.
This protoar is also found near the
Orion Nebula.
Number 38, LL Pegasy. We're moving on
now to stars near the end of their
lives. Nope, not this bright star, but
rather this dark and mysterious spiral
next to it. This is one of the most
perfect geometrical objects formed in
space. But what is it?
This is actually a pre-planetary nebula.
Basically, a massive star found behind
all this dust in the center is shedding
some of its mass potentially before it
erupts into a planetary nebula.
The difference between a pre-planetary
nebula and a planetary nebula is that
pre-planetary nebula is a reflection
nebula. Meaning it is illuminated by the
light reflecting off it. Whereas a
planetary nebula consists of extremely
hot ionized atoms which produces its own
light.
In this image, the material forming the
spiral is moving at 50,000 kmh.
And by combining this speed with a
distance between the layers is estimated
to produce a ring roughly every 800
years.
They believe this is directly related to
the fact that this is a binary star
system. The orbital period of which is
thought to also be 800 years. This means
the spiral is the result of the orbital
motion between the two stars as one
sheds its mass.
Number 39. Another pre-planetary nebula
is HD44179.
A unique nebula with a rectangular or an
X shape. This nebula is really hard to
see from a ground telescope due to the
Earth's atmosphere and is one of the
situations where having Hubble in space
is really useful.
This pre-planetary nebula has really
baffled scientists who don't know the
exact mechanics of how this structure
formed.
But there is evidence that this is due
to another close binary star system with
a star about the mass of our sun
shedding its mass before it turns into a
white dwarf.
It's the remaining white dwarf that will
eventually radiate UV light, ionizing
the ejected gas to become a planetary
nebula.
Number 40. Let's have a look at a
completely different type of star with
RS Papus. This bright star at the center
of the image is our focus in this image.
And there is something very unusual
about this star. It is a variable star
known as a sephiide variable.
This means it varies in brightness by a
factor of five once every 40 or so days.
Because this star is surrounded by a
beautiful dust structure, we can see the
variable nature of this star through a
light echo. Light travels extremely
fast, but it still takes a long time to
get across astronomical distances.
This means we can see the procession of
light traveling away from the star with
some rings being dark as the star was
dimmer and some rings being brighter as
the star brightened.
Hubble imaged RS Papis over a 5-week
period, and you can actually see this
light echo pulsing.
All in all, a ghostly yet beautiful
image.
Number 41, AG Karina.
This star is another variable star, but
it is one of the brightest in the Milky
Way. Because it is so bright, it is also
short-lived as it is shedding its mass
through solar winds at an incredible
rate and at speeds of up to 7 million
kmh.
Much of the surrounding material around
this star is part of the ejected mass of
the star being further sculpted by the
solar winds. As you can see,
one day this star will become a wolf ray
star, a type of star millions of times
more luminous than our sun. However,
right now it's so hot that it isn't
visible to the naked eye as much of its
output is in the ultraviolet.
Number 42, NGC4993.
So far, all the stars we've looked at
have been found in our own galaxy.
Outside the galaxy, individual stars are
pretty hard to observe typically.
But sometimes cataclysmic events happen
in other galaxies that are so big we can
observe it millions of light years away.
And this is what happened with NGC 4993
where something even more spectacular
than a supernova happened. A killer
nova. In August 2017, LIGO detected
gravitational waves from the collision
of two neutron stars. And within 12
hours, the source of these gravitational
waves had been discovered. Considering
it is so bright and evident 140 million
lighty years away, I can't imagine what
it would have been like from within the
same galaxy. These neutron stars will
have combined to form a black hole and
the resultant kilanova explosion will
have emitted electromagnetic radiation
in every frequency from radio waves to
gamma rays. Interestingly, it is
believed that neutron stars colliding
could be the main source of heavier
elements such as gold in the universe.
If that is true, it gives your jewelry a
bit of a new perspective, I think.
Number one, this spectacular collection
of stars is the NGC1850
double star cluster found in the large
magnanic cloud, a satellite galaxy to
our own Milky Way.
NGC1850
consists of a main globular cluster in
the center and a younger, smaller
cluster seen below and to the right. The
main cluster is about 50 million years
old. The smaller cluster is only 4
million years old. It's composed of
extremely hot blue OB stars and fainter
red Tori stars. Tori stars are younger
stars that are still forming. So young
in fact that they may not have even
started converting hydrogen to helium
which is how our sun produces its
energy. Instead they radiate energy
released by their own gravitational
contraction. You see, when a star cools,
the cooling causes the pressure to drop
and the star shrinks as a result. This
compression in turn heats up the core of
the star. OB stars, on the other hand,
are some of the brightest and most
massive stars out there. In this image,
you can also see the remnants of stars
that have gone supernova, leaving behind
this super bubble of diffused gas known
as N103,
which looks similar to the well-known
supernova remnant Signis Loop in our own
Milky Way. It is believed that the birth
of new stars can be triggered by the
enormous forces in the shock fronts
where the supernova blast waves hit and
compress the gas. Hence why you find
these very young stars in these
clusters.
Number two, the Red Spider Nebula, also
known as NGC6537.
It's a planetary nebula found near the
heart of the Milky Way. What produces
nebula is often when a red star is
dying, the outer layers of the star
shoot off into space by strong stellar
winds. Once the atmosphere has
dissipated, the hot and bright core of
the star emits UV radiation, which
ionizes the ejected outer layers. The
absorbed UV radiation energizes the gas
of the planetary nebula, which produces
all sorts of different colors.
This two-lobed symmetric planetary
nebula definitely looks like a spider
and houses one of the hottest white
dwarfs ever observed, probably as part
of a binary star system. The star itself
is not visible in the image because it's
so hot. Most of the light it radiates is
in the ultraviolet.
Internal winds emanating from the
central stars have been measured in
excess of 1,000 km/ second. These winds
expand the nebula, flow along the
nebula's walls, and cause waves of hot
gas and dust to collide.
Number three, this planetary nebula,
NGC2080,
or the Ghost Head Nebula, is another
member of the Large Magleanic Cloud
Satellite Galaxy. It's called the Ghost
Head Nebula because of the two distinct
white patches it possesses, which look
like ghost size. The western patch
called A1 has a bubble in the center
which was created by the young massive
star it contains. The eastern patch
called A2 has several young stars in a
newly formed cluster, but they are still
obscured by their originating dust
cloud. Because the dust clouds are still
around the two sets of stars,
astronomers believe these stars are not
more than 10,000 years old. The nebula
is 50 light years across. And if you
look to the left of the picture, you'll
see a lot of green. This is due to
ionized oxygen atoms. Whereas with the
rest of the nebula, you find ionized
hydrogen atoms producing this reddish
color.
Number four, the Tadpole Galaxy. Now,
I've already covered that galaxy in my
top 10 most beautiful galaxies video.
So, if you want to find out more about
this remarkable galaxy, I'll leave a
link in the description. So, check it
out.
Number five, NGC4676
or the mice galaxies.
Nicknamed so because of the long tail of
stars and gas emanating from each of the
spiral galaxies. They're both very
irregularly shaped as they in the middle
of colliding with each other. Although
it is thought that they will eventually
form one single spiral galaxy. They are
a massive 290
million lighty years away.
Interestingly, in the zip file of the
top 100 Hubble images, the image of the
mice galaxies appears to have another
galaxy just above it. After some
research and with the help of Reddit, it
seems this galaxy is there by accident.
I couldn't find anything else on it. So,
it seems someone in the Hubble team was
just a little trigger happy with the
clone tool as this galaxy is not in any
other picture I found of it. Number six.
This is the cone nebula, part of the
bigger NGC2264
or the Christmas tree cluster. If we
rotate the image, you can see why. It
definitely has a Christmas tree shape.
Plus, the star clusters could be seen as
Bbles or Christmas lights. This star at
the trunk of the Christmas tree is a
massive Otype star.
Looking at the infrared makes the cone
nebula stand out very clearly.
The nebula is about 2,700 lighty years
away from us. And this section of the
nebula is about 7 lighty years long. The
structure and color of the nebula comes
from ionized hydrogen. The UV radiation
coming from the clusters young stars.
Number seven. This is the Hubble ultra
deep field. Another picture we have
already looked at in another video.
Since then though, I have found a very
cool animation giving us a 3D view of
what the ultra deep field would look
like. Each one of these dots is a
galaxy. Each one containing millions
upon billions of stars. In fact,
astronomers have counted around 6,000
galaxies in this one image alone. And
what is even more interesting to me is
that we are actually looking at
different times right now. The closer
galaxies we see come towards us first in
the animation are maybe only millions of
light years away from us. Whereas at the
back of this image are galaxies which
are billions of light years away. They
may not even exist now. It's just that
all the light from these galaxies hit
the telescope's lens at the same time.
But in actual fact, the further back the
galaxy, the further back in time we are
looking.
Number eight, and we're visiting the
large magnanic cloud again. This star
forming nebula is part of a region
within this galaxy called N11 and is one
of the most active star formation
regions in the nearby universe. Zooming
out a bit, you can see why there are so
many densely packed star clusters full
of young stars made up of the dust and
gas of this giant nebula. Zoom out again
and we can see where the original
picture fits in. It's hard to think that
we can resolve the individual stars in
another galaxy, but I'm glad we can
because the end result is breathtaking.
The colors of the different pictures are
because they were taken with different
telescopes which pick up different light
wavelengths, for example, infrared or
ultraviolet.
Number nine, V838 Monoserotus.
This is a red variable star 20,000
lightyears away from us. In February of
2002, it underwent a huge eruption,
increasing in brightness massively
before dimming again, as is expected
with these kind of eruptions. But then
in early March, it increased in
brightness again before dimming once
more. And again in April, it increased
in brightness before dimming again to
its previous level before the eruption.
It is unlike anything that has ever been
witnessed before. At its peak, it was
one of the brightest and biggest stars
in the Milky Way galaxy at over 1
million times more luminous than our
sun. We don't know what caused the
eruption, but theories abound, ranging
from nova outbursts to two stars
colliding or even the star swallowing
one of its giant planets.
The structure you see around the star is
its light echo.
Because light to us seems very
instantaneous, it's quite hard for us to
wrap our heads around a light echo. But
it is very much like a sound echo. And
uh the best way I can show you is
through this. This marble represents
Earth and the ripple represents the
pulse of light which shot out from this
star. Unobstructed, the ripple would
look like this. But because there was a
lot of dust around this star, when the
light shot out in all directions, it
bounced off the dust and created a
second ripple which then reached the
Earth. Now, this is still in the process
of happening, which is why the structure
looks like it's expanding.
Interestingly, when the star first
increased in apparent magnitude, it was
so bright that it was shining in blue,
as you can see from the outside of the
light echo.
Number 10, M51, the Whirlpool Galaxy.
This was also featured in the Galaxy's
video, so I'll leave a link in the
description if you want to know more
about that, too.
Number 11, the Spire.
The object is actually a tower of cold
gas and dust, part of the Eagle Nebula
Stella Nursery. The Spire is a massive
9.5 lightyear high.
The spire is actually being eroded by
thousands of hot young stars found in a
cluster just off this image. This haze
around the structure is hydrogen gas
being boiled off by ultraviolet light.
Whereas the black regions are denser,
more resistant gas. This process may
well be producing more stars too, as
seen here where the bright heated gas
pushes against the dark colder gas. This
pressure may well cause stars to form.
Stars are also formed within the tower
where dense gas collapses under gravity.
These bumps may appear small, but they
are actually the size of our entire
solar system. The stars will continue to
grow as long as there is gas around to
feed it. The background of the image is
more distant illuminated gas. Blue is
ultraviolet light interacting with
oxygen and red is hydrogen.
12 NGC 346.
We're now traveling 210,000 lighty years
away to a satellite galaxy of ours, the
small maganic cloud.
NGC 346 is one of the most dynamic and
intricately detailed star forming
regions in known space. In the center of
this region is an intense and brilliant
cluster of stars surrounded by a jagged
arch of dark cool gas.
As in the last image, the UV light from
these stars is blasting against this gas
structure. You can see the wind trail
left behind these denser globules.
This star cluster also houses the
brightest star in the small maganic
cloud.
Number 13, the Crab Nebula.
This nebula is the remnant of a star
going supernova.
Interestingly, it is documented that
ancient Japanese and Chinese astronomers
saw this explosion in 1054.
What you're looking at here is the
remains of that star being mostly
hydrogen gas. Barely visible at the
center of this picture is a neutron
star, the ultra dense core of the
exploded star.
It is only 30 km across and rotates an
amazing 30 times per second. As it
rotates, it shoots off two streams of
highowered X-ray beams into space. This
is why when observing the star, it looks
like it's pulsating.
This star is the cause of the bluish
glow of the nebula.
Number 14, the Orion Nebula. I must say
this is one of my favorite pictures
Hubble has ever released. The colors are
gorgeous. It looks like it should be in
an art gallery. Plus, there's so much
going on. The Orion Nebula houses about
3,000 stars, some of which weren't
discovered until this picture was taken.
In the center of the bright patch are
the four biggest stars in the nebula,
arranged into a trapezoid, and they're
aptly named the trapezium.
Around these stars are extremely young
stars that likely still have their
protolanetary discs. As you can see
here, these discs of condensing gas
could well form into planets in the
distant future. At the top left here, we
have one star illuminating the
surrounding dust, a region called M43.
We have more dense gas resisting erosion
by UV light
and gas reacting to it.
You can visibly see the bow shock from
some stars as they resist the stellar
wind of the biggest stars. On the left
is a cavity wall of the nebula. And
interestingly, the dim red stars you see
here. These tiny pixels really are brown
dwarfs, sometimes referred to as failed
stars. Brown dwarfs are stars that
cannot sustain nuclear fusion in their
cores like our sun does. As a result,
they're comparably cool, less massive,
and not as bright. And finally, the
Orion Nebula is the closest star forming
region to us, being over 1,300 light
years away. Number 15, the Pinwheel
Galaxy. We're having a little break from
Nebula now and looking at something a
lot bigger. The Pinwheel, also known as
M101, is what is known as a grand design
spiral galaxy. The image itself is
massive and we can take a detailed
journey from one side to the other. It
is a reasonably close neighbor galaxy to
our own being only 21 million lighty
years away and is also a similar size to
the Milky Way. It has very distinct arms
and an unusually high ratio of star
forming regions for a galaxy seen where
the colors are strongest. This means
it's a very active galaxy. The reason
for this is because of exploded stars,
superheated gas, and material falling
towards black holes.
Number 16, the Cigar Galaxy, also known
as M82. This magnificent starburst
galaxy is remarkable for its ejected
flamelike red hydrogen gas. Young stars
are being born 10 times faster in this
galaxy than they are inside our own
Milky Way.
This is thought to be because of
interactions with its close neighbor
M81. They are only 300,000 lightyears
apart and because of their immense
gravity, they have these tidal effects
on each other.
M82 houses the brightest known X-ray
pulsar called M82X2,
which is the big pink dot in the middle
of this picture. It's left astronomers
scratching their heads as it's pumping
out 100 times more X-ray radiation than
something of its mass should be able to
do. As a comparison, X2's binary system
companion M82X1,
which is the pink dot to the bottom
right of X2,
is a black hole, but surprisingly it
emits less X-ray radiation.
Number 17, Cassiopia A.
This is the colorful aftermath of a
supernova explosion of a star. It is the
youngest remnant of a supernova
explosion in our galaxy and is only
11,000 lighty years away. The light
hitting Earth from this explosion would
have happened about 300 years ago.
Although there is no record of any
sightings. This could be because the
outer layers of the star were already
ejected and so absorbed the light from
the explosion. But it's not really known
why. Incredibly, the explosion shell is
still incredibly hot, about 30 million°
centigrade,
and is still expanding at 6,000 km per
second. This shell is about 10 lighty
years across by now.
Number 18, the Lobster Nebula. This is
another beautiful nebula found in the
Milky Way around 11,000 lighty years
away from us. It also contains a lot of
protostars found with dark discs and
cocoons of gas obscuring the stars view.
This star cluster is known as Pismus 24.
Pismus 241 was thought to be the most
massive star on record at 300 solar
masses. It turns out though this is
actually a multi-star system and is in
fact at least three stars each about 100
solar masses. Even with this reduction
in size though, they are still some of
the most massive stars that we know
about.
Number 19, NGC602.
This picture is not just beautiful for
its shapes, blues, and oranges, but also
because of all the galaxies in the
background. The reason these galaxies
are so clear is because NGC 602 is found
away from the center of the small
maganic cloud, meaning there's not so
many stars to distort the view. This
also makes the nebula a lot easier to
study. In the center is a cluster of
young bright stars eroding the dust
walls away.
Finally, number 20, NGC1672.
This is the last image for this episode.
And what we have here is a bar spiral
galaxy. It has these two arms which come
away from the rest of the galaxy. The
one on the left being a lot more
prominent than the other. This galaxy
actually has four arms. The final two
that's not so defined and they're tucked
away inside the galaxy. And
interestingly, these arms do not join at
the nucleus, but rather at the end of
this straight bar of stars. This is
actually why it's referred to as a bar
spiral galaxy. Around the bar, the
galaxy is experiencing starburst, an
extreme amount of star formation.
NGC 1672 is an impressive 60 million
lighty years away.
Number 28, Dadus 30 or the Tarantula
Nebula. This image is a small section of
what is known as the Tarantula Nebula.
The Tarantula Nebula is a huge,
impressive nebula found in the large
magnanic cloud, a satellite galaxy to
our own. Some may argue it isn't as
pretty as some of the other nebula we've
looked at so far. But I must say it does
look good in its own right. But if it
isn't its looks that make this nebula
stand out, what is it and what sets it
apart from anything we've looked at so
far? Well, we'll come back to that.
Let's first of all give you some
context.
So where is it? Well, this is the large
magnanic cloud. The largest of the Milky
Way satellite galaxies. And as you see,
it has a lot of nebula. The one we're
focusing on, the Tarantula Nebula, is
the brightest and biggest nebula in this
galaxy. And it really is bright. I
selected this image because it still
shows some of its details. Most other
images I found show it as this bright
overexposed spot. It's so bright that if
this nebula was as close to us as the
Orion Nebula in our own Milky Way, it
would cast shadows at night. Let's zoom
in to find out why.
The Tarantula Nebula is currently
undergoing extreme star formation. In
fact, it's the most active star forming
region in the whole local cluster of
galaxies. To its center is a region of
stars
known as NGC2070.
The central concentration of stars known
as R136.
It's this star cluster that produces
most of the energy to make this nebula
visible. It's a really big cluster with
an estimated 450,000
solar masses contained within it. Now,
if you've ever wondered what the most
massive and brightest known star was,
look no further. One of the stars in
this cluster known as R136A1
is the most massive and brightest star
on record with some pretty incredible
statistics. It's a Wolf Ray star, 315
times the mass of the sun and 8.7
million times more luminous. It is also
one of the hottest stars at 53,000°.
While it is the most massive star, it
isn't the biggest, although its size
still dwarfs the sun. As always with
these massive stars, it will only be
short-lived, and it will almost
certainly become a black hole at the end
of its life. In the meantime, it's
shedding its mass through solar wind at
a very fast rate. Since its birth, it's
thought it's already lost 50 solar
masses to space. Overall, the R136 star
cluster is thought to be only about 2
million years old. It's currently
merging with another close by cluster.
The two clusters together making up
NGC2070.
You may not think that there are enough
stars in this image to make up 450,000
solar masses, but these blue stars you
see in this image are only the very
brightest O type stars in the cluster.
Interestingly, there is a star that
belongs to this cluster which isn't
found anywhere in the area. If we zoom
out a bit, you'll find this star over
here. It's called 30 Datus016.
And the young star only 1 to two million
years old may have traveled about 375
lighty years from its suspected home in
the star cluster R136.
And it's still traveling about 400,000
kmh. But how did it get all the way out
here? The theory is that it was part of
a binary star system when another even
more massive star entered the system and
kicked out the now homeless star. These
other stars would have had to have been
extremely massive as 30 Duratus016
is no minnow at a suspected 90 solar
masses.
It is now an explorer destined to travel
the far reaches of the large maganic
cloud.
There is another old star cluster found
in the Tarantula Nebula called Hodgej
301.
It is roughly 20 million years old with
some stars 10 times as old as those
found in R136.
Within this star cluster, there are
thought to have been at least 40 stars
that have gone supernova, whereas in
R136, there have been none. This is
because of the age of Hodgej 301. Some
of the shortest lived stars have already
gone through their entire life cycle.
More stars in this cluster are on the
verge of exploding in a supernova, too.
So, watch this space.
The original image we looked at is
further away still from the center of
the Tarantula Nebula, although it's
still part of it in an area called
NGC2060
found over here. It's a star cluster 2,
although the stars here are much more
loosely dispersed than in R136 and
Hodgej 301.
In fact, these stars are no longer
gravitationally bound to each other, and
in a few million years, the stellar
group will disperse completely. It's
currently about 10 million years old,
and there are some very interesting
things found in this area. The first
I'll mention is that the whole of
NGC2060
is a supernova remnant about 165 lighty
years across. It's estimated that the
supernova occurred about 4 to 5,000
years ago. And consistent with this
theory, a pulsar neutron star is found
in this area here around the same age as
the supernova. It's not really visible
in visible light as it emits X-rays,
which means you need the X-ray telescope
Chandra to see it. And it's right in the
middle of this bubble. The bubble itself
is the supernova remnant.
The pulsar rotates exceptionally fast,
once every 16 milliseconds.
Interestingly, it's not the fastest
rotating star in this region. That
accolade belongs to this runaway blue
super giant VFTS102.
It's actually the fastest rotating star
that we know of, rotating a speedy 2
million kmh.
This is 100 times faster than the
rotational speed of our sun. It spins so
fast that the star is flattened with an
equatorial disc extending out due to
centrifugal forces.
It is suspected that this runaway star
actually was part of the same system as
the pulsar and would have had a hand in
its supernova explosion. Before the
supernova, they would have been two blue
stars orbiting one another. One would
have evolved into a red super giant and
as it expanded it would have started
feeding its mass into the other star
speeding the rotation of the other. Once
the red super giant exploded in a
supernova it ejected the other star at a
tremendous speed into space. VFTts 102
fits this model as it's spinning rapidly
whilst also hurtling through space in
relation to its stellar neighborhood.
Zooming out further again, we are
getting to the edge of the Tarantula
Nebula. At its longest points, the
Tarantula Nebula is an incredible 1,000
lightyear across. I already mentioned
this nebula is the most active star
forming nebula, known as an H2 region in
our local cluster of galaxies, but it is
also the biggest. If it was as close to
us as the Orion Nebula, it would be
twice as big in the sky as the Big
Dipper. And because it's so bright, it
would even be visible during the day. At
the far edge of this nebula is perhaps
its most remarkable visual spectacle.
It's called SN 1987A,
and it's a supernova remnant. It is a
lot younger than any of the other
supernova we've looked at so far. In
fact, it's less than 30 years old. The
light from this supernova hit Earth in
1987 and was visible to the naked eye.
It was the first supernova observed
since the 1600s and the only supernova
observed that we've had a close look at
using modern-day telescopes. When it
exploded, it was a blue super giant,
which means it was only about 1/10enth
of the brightness of a red super giant
supernova. Haven't had the chance to
look at it now? I bet you're wondering
what these rings could be. Well, they
are the mass thrown off by the star
through stellar winds, coughing and
spluttering its inards out thousands of
years before the supernova. The initial
flash from the explosion lit the rings
up at first, but when the supernova
shock wave hit them a few years later,
they lit up again due to interactions
with the rings and the debris from the
shock wave. SN1 1987A is now a true
supernova remnant in the vein of
Cassiopia A, illuminated not by the
explosion of the star, but by continual
processes between the debris of the
supernova and the material beyond it.
This artist's illustration of SN1 1987A
is based on real data and reveals the
cold inner regions of the exploded stars
remnants. this patch here in red where
tremendous amounts of dust were detected
and imaged by the ALMA telescope. It's
in this dust that the leftover pulsar
could be hiding because nothing has been
detected where the pulsar should be.
Another option could be that it didn't
turn into a pulsar at all, but is
actually now a black hole.
I'm happy to announce we have a weekly
newsletter to keep up with all the
discoveries in our cosmos. And our
designer, Peter, has made the most
beautiful email you'll ever receive.
Sign up with the link down below. It's
the best way to stay connected between
videos. Short, focused updates on what's
new and fascinating in space each week.
No spam, no filler, just the good stuff.
You'll get the latest news, visuals, and
insights delivered straight into your
inbox. If you enjoy Astramm videos,
you'll love this. Join the newsletter
and stay curious with us.