A lot of places celebrate the New Year with firework displays.
But let’s face it, even all the fireworks on Earth
are no match for the light show that space is ready
to put on at the drop of a very large cosmic hat.
And massive explosions aren't the only
astronomical wonders we discovered in 2023.
Scientists also detected one of the universe's
oldest galaxies and the most magnetic star.
Here are just a few of the space superlatives we found in 2023.
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We’re starting off with a bang!
AT2021lwx, nicknamed Barbie or Scary Barbie,
is the most energetic explosion we’ve ever witnessed.
This massive explosion pumps out more than
ten times as much light as a typical supernova.
And the weird thing is, we’re not even sure what it is.
This event was first discovered back in 2020,
but it’s still going on, leading researchers to realize
it’s something we have never seen before.
Unlike quasars, which are supermassive black holes
at the center of galaxies that feed off of the material around them,
this explosion is transient, meaning it doesn’t last
for very long in astronomical terms.
But, so far, Barbie has lasted a lot longer than other transients
like supernovas, which are usually only visible for a few months
before fading into the background light of their host galaxies.
Barbie is more luminous than any other known similar transient,
outshining most by orders of magnitude.
The amount of light or energy something gives off
per second is called its luminosity.
But the amount of light we end up
seeing is called its apparent brightness.
The brightness depends on how far away it is.
When scientists know the distance to an object or event
and its brightness, they can calculate how much light it is giving off.
Scientists originally thought Barbie might be a Tidal Disruption Event,
which is when a star gets too close to a black hole
and is destroyed by its gravity.
But research published this year suggests that instead of a single star,
it may actually be caused by a cloud of gas millions of times
the mass of our sun being ripped apart by a supermassive black hole.
There’s still a lot scientists don’t understand,
but they hope future studies will continue
to shed new light on what’s up with Barbie.
Now, we’re going from the biggest explosions
to the faintest galaxy in the early universe.
Because sometimes, it’s the dimmest flickers of light
that can tell us the most.
In 2023, scientists used data from the James Webb
Space Telescope to take a peek at JD1,
one of the observable universe’s faintest galaxies.
JD1 was originally discovered in 2014,
but to tell just how little light it was giving off,
astronomers needed to pin down its distance.
To measure JD1’s distance, they needed to determine its redshift.
When an object that gives off light is moving away from us,
those waves of light get stretched, causing the object
to look redder than if it were still.
Because the universe is expanding, the farther away a galaxy is,
the faster it is moving away from us.
Which then means, it’ll look more red.
Scientists use how red something is to figure out how far away it is,
and if they know how far away it is,
they know how far back in time they are looking.
In the case of JD1, they’re looking so far back in time -
a mere 480 million years after the Big Bang -
that the light has been so stretched it has become infrared.
And that’s why the JWST was needed to confirm its distance,
because it can detect that infrared light so well.
With the new measurements of distance and brightness,
scientists were able to determine its luminosity,
confirming it really is the faintest galaxy
we have ever seen from that time period.
Galaxies like JD1 aren’t just dim because they are so far away,
but also because their stars are in the early stages
and only beginning to develop.
Studying dim galaxies like JD1 can help astronomers
understand the development of the early universe.
The period of time this baby galaxy is from is called
The Epoch of Reionization, right after the infamous Cosmic Dark Ages.
In those dark days, the universe would have been filled with
intergalactic hydrogen, preventing light from traveling
very far before being absorbed.
If the photons of light were absorbed,
they wouldn’t be able to zoom out across the universe
to eventually wind up in our telescopes.
So the universe was considered opaque.
Scientists think early galaxies and the stars
within them produced ultraviolet radiation with very high energy.
So much so that when it hit hydrogen gas,
it knocked off electrons or ionized it.
That allowed light to travel more easily,
making the universe transparent.
Although big bright galaxies in the
early universe are the easiest to spot,
scientists think it was smaller, faint galaxies like JD1
that played the biggest role in clearing up the haze.
So, studying those galaxies will give us a window into
how our universe evolved and came to be the way it is today.
For number three, let’s talk about magnetars.
And no, that’s not a Pokemon; it’s a kind of neutron star
with a gigantic magnetic field that’s created
after a massive star goes supernova.
While magnetars are relatively easy to spot, they’re also rare.
So it’s been hard to tell what the exact
celestial recipe to produce one is.
That’s why scientists are excited to have found HD 45166 -
the most massive magnetic star ever observed.
Its magnetic field is over 100,000 times as powerful as Earth’s.
But apparently that much magnetism isn’t enough
to make this star a true magnetar - not yet, anyway.
A study from this year suggests that HD 45166 is not a magnetar now,
but it might be on its way to becoming one.
The typical life of a massive star starts as a ginormous
cloud of gas and dust that gets pulled together by gravity into a ball.
As the ball of material grows, the gravity becomes greater and greater,
increasing the pressure and temperature at its core.
When it becomes hot enough, atoms are forced to slam into each
other, fusing into heavier elements and releasing extra energy.
The pressure from fusion keeps the star from collapsing in on itself
for millions to billions of years.
But eventually, the star fuses through
all its available fuel, collapses in on itself, and rebounds back
outward in a giant explosion known as a supernova.
After they do this, most massive stars leave behind neutron stars,
which are ultra-compact objects with all the mass of a star,
but only the size of a single city.
For unknown reasons,
some of those dead stars have powerful magnetic fields,
which makes them magnetars.
Scientists think that HD 45166 might be
the missing piece of that puzzle.
Maybe the star has to already have a powerful
magnetic field to produce one after it blows.
But, this star isn’t just interesting because of its magnetic field.
It also resembles a Wolf-Rayet, a rare type of massive star
that has lost its outer hydrogen layer, revealing the helium
that’s normally buried deep inside.
Interestingly enough, it isn’t as massive or
luminous as a typical Wolf-Rayet star.
And unlike other Wolf-Rayets,
it may have even formed from the merger of
two smaller helium-rich stars.
It ‘s not clear yet if all future magnetars have to have
the same conditions as HD 45166,
but studying this star may be a first step in unraveling the mystery.
To wrap it up, let’s look at something a little closer to home.
Scientists discovered evidence of the largest known solar storm
to ever hit Earth, and they didn’t even need to fire up
their telescopes to do it.
So where did the details come from?
Tree rings.
While studying ancient trees in the French Alps,
researchers found a huge spike in radiocarbon,
or Carbon-14, levels from about 14,300 years ago.
Normally scientists use carbon-14 to help date
bones or other remains of living things.
But in this case, they were able to learn about
what was happening in the sky.
One way this carbon isotope is produced is by
interactions with charged particles
from the Sun in our upper atmosphere.
If a massive storm hit the planet, large amounts
of the isotope would have been produced
and then incorporated into the tree’s tissue through photosynthesis.
Our Sun goes through 11-year cycles of waning and waxing activity.
During active periods, it can send huge
blasts of charged particles out into space.
Most of the time, these solar tantrums don’t end up hitting our Earth,
but sometimes they slam into our magnetic field and atmosphere,
causing auroras and making lots of radiocarbon.
For our ancestors living in the ice age,
this would have been beautiful, not dangerous.
Today, however, our global infrastructure can be
majorly impacted by these solar events.
They can damage satellites, disrupt communication,
and induce electrical currents in structures like power lines.
They’ve got the potential to cause large-scale blackouts,
and cause billions of dollars in damage.
So, better understanding and tracking these storms
is increasingly important to our modern world.
The more we learn about the universe—its explosions, its storms,
its ancient galaxies—the more we learn about the things
that help us survive on our little blue dot.
And sometimes,
we get one heck of a light show along with it.
I for one, can’t wait to see what we find out in 2024.
Happy New Year, astrophiles!
Space merch - 2024 is going to be a BIG year for space stuff -
for instance, in North America we’ll be able to see a solar eclipse -
get our glasses!
Or stickers!
And speaking of cool space stuff in 2024,
have you heard there’s going to be a solar eclipse on April 8th, 2024?
It’ll be visible across North America,
and it’s the last total solar eclipse we’ll be able to see
in the United States until 2044.
So if you want to make the most of it,
make sure you wear protection–
specifically, our SciShow eclipse glasses.
You can find them, and a whole bunch of great SciShow Space merch,
at store.dftba.com, or using the link in the description.
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