T Betelgeuse Is Acting Weird Again! What’s Happening.?
Betelgeuse has been giving us the “will it, will it not” tension since 2019, but it’s time we try
to understand what is going on with that star. The red giant has moved up from the 10th brightest
star to 7th in ranking, sparking talk of a possible supernova!
Could we be in for a stunning astronomical event? But wait, there's more! This supernova will be
such a big deal that it'll make headlines for weeks. And it's not just astronomers who will
be excited. The whole world will be buzzing about it! Wanna know why? Keep watching this video…
The best part is that we don't even have to worry about any harmful effects since
Betelgeuse is far enough away. So we can enjoy the show from the comfort of our balconies.
Let’s remember a few things about Betelgeuse together, what happened in 2019 and tell you
what’s been going on recently. And if you stay a little longer, you can even discover
the biggest and most powerful cosmic explosion we have ever discovered until today with us!
(roll intro) ---
Betelgeuse Properties Betelgeuse is a relatively young star,
only 10 million years old. In comparison, our Sun is more or less 5 billion years old.
But it’s youth does not imply that it will have a long life to live… Betelgeuse is very massive
and burns its material so much faster than the Sun. Meaning it is expect to die much sooner than
the Sun and is massive enough to turn it into a neutron star or a blackhole after its death.
Did you know that Betelgeuse hasn’t always been a red giant, you’ll be surprised!
Betelgeuse is a special kind of star that's not like most others, especially considering
it used to be a real monster. It used to be a blue-white O-type star, which is the heaviest
kind of star out there. These kinds of stars use up their hydrogen super fast. The Sun,
that is billions of years older, is only halfway through its lifetime of hydrogen-burning.
Betelgeuse's spectral type has changed because it's almost out of hydrogen.
Now, the red giant is fusing helium into carbon and oxygen and has gotten super big, about 764
times the size of the Sun and 16.5 to 19 times as heavy. It's so huge that if we swapped it with our
system’s star, it would reach beyond Jupiter's orbit! Eventually, it'll run out of fuel,
go supernova, and throw off its outer layers, leaving behind a tiny core called a neutron star.
Scientists knew that eventually, it would explode in a supernova,
but it might take another 100,000 years. In 2019, the star started to dim and by February 2020,
it had lost two-thirds of its normal brightness as seen from Earth. What happened then?
--- The Great Dimming 2019 Recap
Scientists studied the unusual dimming and found out that it was not because of
an imminent supernova but because of a giant dust cloud that had obscured some of the star's light.
They used the Hubble Space Telescope to discover that the dust cloud was caused
by an enormous ejection from the star's surface. It produced a shock that blew out a chunk of the
star's surface 400 million times larger than those usually seen in the sun's coronal mass ejections.
This new phenomenon is something that scientists have never seen before in star science.
Scientists are in fact watching stellar evolution in real-time.
The new research also incorporated information from different types
of data to put together a narrative of the blowout and its aftermath.
The eruption blew off a chunk of the star's lower atmosphere, called the photosphere of the star,
leaving behind a cool spot that was further occluded by the dust cloud from the blowout.
This neat patch of dust and cloud is the reason Betelgeuse's light got dimmer.
The star is still experiencing the aftermath of this event, according to scientists.
Before this happened, Betelgeuse had a regular pattern of getting dimmer and
brighter over a 400-day cycle. But that cycle had disappeared - at least we thought so for a while.
So what is going on now? What has changed? ---
New Discoveries The star has been acting very weird lately,
some might say that their hopes to witness a supernovae in their lifetime has been renewed..
The star’s brightness has been increasing up to 150% more than its average brightness, making it
harder and harder to find explanations based on what we know so far in stellar evolution.
It is without a doubt that Betelgeuse has had a long and wild history of brightness variability,
but so why are we so surprised? Well, it isn’t quite normal that
Betelgeuse increases so much in brightness in such little time,
so the only plausible conclusion to make is that the star’s 400-day cycle has been cut to half.
This pulsation cycle is basically us seeing the star when it expands and contracts.
We have found that a "convective plume" inside the star could be what is causing material to
break away from it, disrupting its 400-day cycle and giving it a new 200-day cycle.
This disruption could be linked to the recent extreme dimming that has happened to Betelgeuse.
Think of it like taking a chunk out of a cake; everything else starts moving around and doesn't
settle back into place right away. However, the team of experts studying the variable star think
that it will eventually return to normal and continue to live peacefully for a long time.
--- Supernovae Explosions
How will we know if it’s about to explode? The first sign of the supernova will be a wave
of ghostly neutrinos that will hit earth, lighting up detectors worldwide. Let’s go into details.
Did you know that there are two types of supernovas? The first, called Type I,
happens when a white dwarf star pulls material off a companion star until it explodes and sends
debris flying through space. Kepler's was a Type I. The second, called Type II or a core-collapse
supernova, happens when a star runs out of nuclear fuel and collapses under its own gravity, then
"bounces" and triggers an explosion. Both types can be super bright and outshine an entire galaxy,
but Type II supernovas are extra interesting because they release lots of neutrinos, and they
are the subject of our target star in this video. Neutrinos are particles that can start to
be released before the actual supernova explosion happens. If a star is close enough,
we might be able to observe these early neutrinos before the explosion even happens!
For example, if the red giant star Betelgeuse were to go supernova on us, we could detect its
neutrinos hours or even days before the explosion was visible, and this is how we know that it
won’t just explode randomly at any moment! When a galactic supernova happens and its
neutrinos reach Earth, astronomers will get an automatic alert from a system called SNEWS. Today,
they are working on "SNEWS 2.0," which will be even better at pinpointing the supernova's
location in the sky. The system will use data from seven different neutrino detectors around
the world to help optical instruments take a closer look. How cool is that?
--- Cosmic Explosion News Updates
Betelgeuse isn’t our only supernovae news, and frankly, it is starting to get messy and weird.
So let me change your ideas a little, get out of the subject and tell you about an actual recent
explosion that we were able to detect!! But not just any explosion, a cosmic one!
The explosion, called AT2021lwx, occurred over three years ago and is still ongoing.
It's 100 times the size of our Solar System and is comparable to a fireball. The scientists who
made this discovery believe that a gigantic cloud of gas, thousands of times larger than our sun,
was disrupted by a supermassive black hole, thus causing the explosion. The explosion is
so rare that it's still being studied to determine how and why it occurred.
Scientists from the University of Southampton led the investigation and named the explosion “Scary
Barbie” due to its energy levels. The explosion initially remained anonymous until astronomers
at the Zwicky Transient Facility in California discovered it. The Asteroid Terrestrial-impact
Last Alert System (ATLAS) in Hawaii then picked it up, and it has been studied ever since.
The explosion is approximately 8 billion light-years away from Earth and occurred
when the universe was only 6 billion years old. You might be confused as to why we only saw it
happen 3 years ago, but make the count! The Universe is 13.7 billion years ago,
it happened 6 billion years after the Big Bang and its light took 8 billion years to reach us!
The researchers believe that the explosion is far too bright to be a supernova, which usually lasts
a couple of months before fading away. It is estimated to be about 2 trillion times brighter
than the sun, and it has left astronomers baffled as they have never seen anything like this before.
Though AT2021lwx is comparable to a quasar, which occurs when supermassive black holes swallow gas,
there are significant differences. Quasars tend to flicker in brightness,
while AT2021lwx suddenly started flaring up from nothing, and it is still blazing away.
Scientists have looked at other possible explanations, but a tidal disruption event,
where a star is sucked into a black hole, does not explain the explosion's intensity.
Now that scientists know what to look for, they aim to search the skies to see if other
similar explosions have been missed. We may be on the verge of exciting new discoveries!
--- Outro
Well, there you have it, folks! Betelgeuse is still acting weird,
and we're not exactly sure what's going on, but we do know that we're in for a
spectacular show when it goes supernova. And if that's not enough, we've also got Scary Barbie,
the cosmic explosion that's still going strong three years later.
Who knows what other surprises the universe has in store for us? One thing's for sure,
we'll keep our eyes on the skies and be ready for anything. Until next time, keep looking up!
That’s the end of this video, thank you for joining us today, and don't forget to
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Don’t hesitate to let us know your questions and what you think!