Have you ever looked up at the night sky and wondered
all the time just how many different kinds of stars are out there?
I mean, they all look like tiny, tiny little like pinpricks of light.
Right. But yeah, there's there's a whole universe of variety hidden in that in that twinkling.
Absolutely. Yeah, we we tend to lump them all together as stars, but but they're incredibly diverse.
Some are massive and burn bright, bright and fast. Oh, wow.
While others are small and cool and lasting for billions of years.
OK, so let's dive into this. I've got a stack of research here on all sorts of different stars,
and I'm ready for my mind to be blown. What's the what's the most interesting thing you think
we'll uncover in this deep dive? Well, we're going to journey from our own sun all the way to
a star so large that it would engulf Saturn if it were in our solar system. Whoa. Along the way,
we'll we'll explore the incredible power of nuclear fusion. OK, the mysteries of the sun's corona
and the the dramatic deaths of stars that that seed the galaxy for new life.
Welcome to Cosmos and a Pod Space and Astronomy series. All right, you've you've hooked me.
So let's start with the basics. I know stars vary in size and temperature, but what else makes them
so different? Well, their lifespans are dramatically different and and those lifespans are determined
by their mass. So a star's mass dictates how much fuel it has and how quickly it burns through it.
The bigger the star, the faster it lives and the more spectacular its death. So it's like a cosmic
race against time. Exactly. A massive star might live for millions of years. Wow. While a smaller
one can shine for billions, even trillions of years. Trillions. Wow. Yeah. That makes our sun's
10 billion year lifespan seem like a blink of an eye. Yeah, it's it's pretty incredible. Let's
talk about our own star, the sun. Sure. You know, I know it's it's a pretty average star. It is. But
still it's still pretty amazing to me. What makes our sun tick? So the sun is what's called a main
sequence star, which means it's in the prime of its life, steadily fusing hydrogen into helium in
its core. And that fusion is a is a powerful process, releasing a tremendous amount of energy.
Right. That we feel as light and heat here on Earth. It's it's mind blowing to think that all
the energy that powers our planet comes from that nuclear furnace. Yeah. Millions of miles away.
Absolutely. Yeah. It's our it's our lifeblood. And it's not just, you know, a uniform ball of
fire either. Right. The sun has layers. It does. Each with its own. Absolutely. Unique characteristics
and processes. Exactly. Right. I remember reading about the sun's corona. It's like a giant mystery,
isn't it? It is. The corona is the outermost layer of the sun's atmosphere. And what's bizarre is
that it's millions of degrees hotter than the sun's surface. And scientists are still trying to
understand why. I mean, it's it's a it's a like standing closer to a campfire and feeling colder
than someone further away. That's right. It just doesn't make sense. It really doesn't. Yeah,
there are a lot of theories. But the Parker Solar Probe is out there right now collecting data,
trying to unravel this coronal heating mystery. I read that the Parker Solar Probe is the fastest
human made object ever built. It's it's getting closer to the sun than anything we've ever sent
before. Yeah. What's it what's it hoping to find out? So it's it's measuring the solar wind,
which is the stream of charged particles that's constantly flowing from the sun.
It's also studying the sun's magnetic field, which plays a big role in shaping the corona
right and driving those solar winds. So it's not just about understanding our own sun,
but also how stars in general interact with their with their surroundings. Precisely. What we learn
from the Parker Solar Probe will help us understand the dynamics of other stars
and how they impact the planets that orbit them. OK, that's that's a perfect segue to our next
topic. Yeah. Other stars. So we've talked about our sun. But what about what about those red
dwarfs I keep hearing about? Are they are they just miniature versions of the sun? Not quite.
They're they're much smaller. OK. And cooler. And they burn their fuel much more slowly. OK.
That means they have incredibly long lifespans. In fact, some red dwarfs are thought to live for
trillions of years. Trillions. Trillions with a T. Wow. That that makes our sun's 10 billion
year lifespan seem like a blink of an eye. Yeah. Yeah. It's it's amazing, isn't it? Yeah. And
because they're because they're so long lived, some scientists believe red dwarfs might be ideal
places to look for life. Right. Beyond Earth. Exactly. Because they provide a stable environment
for planets to evolve over vast stretches of time, vast stretches of time. One example is Barnard Star,
a nearby red dwarf. OK. Scientists believe there might be a planetary system around it. Oh, yeah.
They are actively searching for signs of habitable worlds. It's fascinating to think about what
what those planets might might be like. So we've got these small long lived red dwarfs on one end
of the spectrum. What about the other end? What are some of the biggest, most powerful stars out
there? Well, let's jump over to the Sirius binary system. You've probably seen Sirius A in the night
sky. It's the brightest star visible from Earth. I think I have. It has a sort of bluish white glow.
Yes. Right. It's a it's a much hotter and more massive star than our sun. But its companion,
Sirius B, is a white dwarf. I remember reading about white dwarfs. They're the remnants of dead
stars, aren't they? They are. Sirius B was once a star much larger than our sun, but it's now
shrunk down to about the size of Earth. So it's incredibly dense. Extremely. A teaspoonful of
white dwarf material would weigh tons on Earth. OK, that's that's mind boggling. So Sirius A is
this blazing hot giant. Right. And Sirius B is its tiny, super dense companion. Right. It's like a
tiny but heavy. Cosmic odd couple. That's a great analogy. And together, they illustrate the different
stages of a star's life cycle. Sirius A is in its prime, while Sirius B is what's left after a star
has burned through its fuel and shed its outer layers. Speaking of shedding layers. Yeah. I
remember reading about a star called WR 102. Right. It's one of those incredibly rare and hot
wolf-rayed stars. It is. It's a it's a it's a beast. Right. What's what's so special about it?
Well, first of all, it's massive, much larger than our sun. But what's really fascinating is
that it's in the process of shedding its outer layers. OK. Spewing out heavy elements. Heavy
elements. What kind of elements are we are we talking about? Things like carbon and oxygen.
The very elements that make up you, me and everything around us. Wait, so we owe our
existence to these massive dying stars. In a way, yes. That's that's pretty profound. It is. It's a
beautiful kind of cosmic connection. And WR 102 is. WR 102 is. Nearing the end of its life. It's
nearing the end of its life. It's burning through its fuel at an incredible rate. And eventually
it's going to explode as a supernova. A supernova. Yeah. Like one of those incredibly bright
explosions that can outshine an entire galaxy. Exactly. And when it does, it will scatter all
those heavy elements. OK. It's been creating out into space. Right. Seeding the galaxy for the
formation of new stars and planets. So it's like a cosmic recycling program. You got it. Death
leading to new life. Exactly. I'm sensing a theme here. Yeah, you're right. There is a theme. The
death of a star is a is a spectacular event. Right. But it's also crucial for the evolution
of the galaxy. Yeah. And WR 102 is just one example. OK. There are many other stars out there
headed for a similar fate. Like Betelgeuse, right? Like Betelgeuse. Exactly. The famous red
supergiant in Orion. The famous red supergiant in Orion, which is a massive star that's nearing the
end of its life. Right. And it's one of the prime candidates for a supernova in the near future,
astronomically speaking, of course. Well, I'm hoping it happens soon. Right. It would be
amazing to witness a supernova. It would be an incredible sight. Betelgeuse would suddenly
become one of the brightest objects in the night sky. Wow. Visible even during the day.
So WR 102 and Betelgeuse are both giants. Yes. Headed for spectacular supernova explosions.
Absolutely. But I remember reading about another another red giant, CW Leonis. What's its story?
CW Leonis is a fascinating star because it's in the process of dying. OK. But in a more gradual
way. It's shedding its outer layers, forming a beautiful planetary nebula. So it's like a
cosmic artist painting the galaxy with stardust. Exactly. And as it sheds its layers, CW Leonis is
enriching the surrounding space with all sorts of elements, including carbon, oxygen and nitrogen.
So it's it's contributing to the cosmic recycling program in in a different way. Exactly. Both
Betelgeuse with its future supernova and CW Leonis with its gentle shedding of layers are showing us
how stellar death is not an ending, but a new beginning. OK, you've you convinced me. No more
no more morning dead stars. They're they're just moving on to a new a new chapter in the in the
cosmic story. That's a great way to think about it. But but we haven't even talked about the real
giants yet. We haven't. Right. You mentioned a star so large it would engulf Saturn. Right. If
it were in our solar system. Tell me more about that. We're talking about Stevenson 218. OK. One
of the largest known stars in the universe. Oh, it's a red supergent located in the Constellation
Scutum. OK. And it's it's so vast it makes Betelgeuse look tiny. I can't even wrap my head around
around that size. It's it's hard to fathom, isn't it? How how do stars like like Stevenson 218 even
get so big? It's all about those incredible thermonuclear reactions happening in their cores.
OK. Stars like Betelgeuse and Stevenson 218 aren't just fusing hydrogen into helium. Right. They've
moved on to heavier elements like carbon and oxygen. So so they've leveled up in the cosmic
fusion game. They have. And these heavier elements require even higher temperatures and pressures
to fuse. OK. That that intense energy output. Yeah. Causes the star to swell to enormous
proportions. But I'm I'm guessing there's a limit to how big a star can get. Right. They can't just
keep, you know, expanding forever. Right. Eventually, even these supergents run out of fuel.
Right. And when that happens, gravity takes over, causing the star's core to collapse. And and that's
what leads to a supernova. Often, yes. But for the most massive stars, the core collapse can be so
powerful that it forms a black hole. OK. Now we're now we're getting into some seriously heavy cosmic
territory. I think I think we need to take a break here and let all this information sink in. I agree.
We've we've covered a lot of ground from our own sun all the way to supergents and black holes.
Yeah. It's it's amazing to think about the incredible variety of stars that populate the universe.
Well, we're only halfway through our stack of research, so I'm sure there are many more surprises
in store. Absolutely. There's still so much to explore in this deep dive into the lives and
deaths of stars. Before we were talking about how even the largest stars eventually run out of fuel,
it's it's like a cosmic balancing act, isn't it? Gravity versus fusion, creation versus destruction.
It really is. It makes me wonder with all this talk about about supergents stars and and their
dramatic deaths, can can planets even exist around them? I mean, wouldn't they just get swallowed up
or blasted away? That's a that's a great question, and it's one that astronomers are still trying to
answer. We haven't confirmed any exoplanets around supergents yet, but that doesn't mean they're not
out there. So it's still possible. It's still possible. What about what about those intense
stellar winds we talked about earlier? Wouldn't wouldn't they just strip away any planets that
try to form? It's it's definitely a challenge. Those stellar winds are incredibly powerful
and they they carry away a lot of material from the stars outer layers. Right. But remember,
the universe is is full of surprises. We're constantly discovering new planets in unexpected
places. So you're saying there's hope. I'm saying there's hope. I love that. I mean, it would be it
would be incredible to to think about like what a planet would be like orbiting a supergents star.
It would be a truly alien world. That's for sure. Imagine the sky. Yeah. Dominated by this colossal
star. Yeah. Constantly changing as the star pulsates and sheds its layers. And what about
what about the radiation? Wouldn't it be incredibly intense? Absolutely. Life as we know it
would likely struggle and survive under such under such extreme conditions. Yeah. But who knows what
kind of exotic life forms might evolve in such a harsh environment? Okay. Now you're just teasing
me with with possibilities. But you mentioned that we haven't actually found any planets around
supergents yet. So where where have we found planets? We've we've had a lot more success
finding planets around smaller, cooler stars like red dwarfs. Right. In fact, one of the most
promising systems is around a star called Wolf 1061. Wolf 1061. That that rings a bell. Isn't
that the one with a with a planet in the habitable zone? You got it. Wolf 1061 c. Okay. Is a rocky
planet. Okay. That orbits within its star's habitable zone. Right. The the region where
temperatures are just right for liquid water to exist on the surface. So there's a chance for life
as we know it on this planet. There's a chance. It's it's definitely an exciting target for future
study. That's amazing. But I'm curious. Wouldn't wouldn't a planet around a red dwarf? Yeah.
Experience some some unique challenges? It would. Red dwarfs are much cooler and fainter than our
sun. So the habitable zone is much closer in. Okay. That means planets in the habitable zone
are what we call tidally locked. Okay. With one side always facing the star and the other side
always in darkness. So permanent daylight on one side and permanent night on the other. Pretty much.
Yeah. That would make for some some extreme weather patterns. It would. Yeah. And red dwarfs are also
known for their their frequent and powerful flares. Okay. Which could be harmful to life.
So so it's a mixed bag, right? Potential for for habitability but also some some serious challenges.
Exactly. It just goes to show that that finding another earth out there is going to be a lot more
complicated than just looking for, you know, planets in the habitable zone. Right. There
there's so many factors to consider. Yeah. From the type of star to the planet's atmosphere
and magnetic field. It makes you appreciate. It does. Just how how special our own planet is.
It really does. But let's not get too distracted by the the search for life. Okay. We still have
a lot more to uncover about stars themselves. Right. Before we were talking about Stevenson
218. Right. One of the largest known stars. Enormous. It's it's mind-boggling to think about a star
that vast. It is. And and it raises an important question. Yeah. Where where do stars like that
even come from? Right. How are they born? So we know stars form from clouds of of gas and dust.
Right. But I'm guessing it takes a lot more. Yeah. Than just a little cloud to create a
supergiant. Yeah. Supergiant are born in vast dense clouds of gas and dust. Okay. Called stellar
nurseries. Stellar nurseries. And one of the closest and most active stellar nurseries is
the Orion cloud. Oh I've heard of the the Orion cloud. It's it's visible to the naked eye isn't
it? It is. If you look at the constellation Orion. Okay. The Orion cloud appears as a fuzzy patch
below Orion's belt. So so when I'm when I'm looking at that at that fuzzy patch. Yeah. I'm
I'm actually seeing a place. You're seeing. Where stars are being born. Where stars are being born.
That's incredible. But what's what's actually happening inside that cloud. Right. How how does
a star go from a cloud of gas and dust to a blazing ball of fire? It starts with gravity. Over millions
of years gravity pulls the gas and dust in the cloud together causing it to collapse. Okay. As
the cloud collapses it heats up and eventually the core gets hot enough to ignite nuclear fusion.
So it's it's like a cosmic pressure cooker squeezing the cloud until a star ignites. That's
a great analogy. And the birth of a star. Yeah. Is anything but quiet. Right. These these stellar
nurseries are filled with all sorts of amazing phenomena like herbig harrow objects. Herbig
harrow objects. I remember reading about those. They're like cosmic jets. Right. Exactly. As the
newborn star spins. Yeah. It shoots out powerful jets of material from its poles. Okay. These
jets slam into the surrounding gas. Right. Creating shock waves. Right. That heat up the gas and make
it glow. So so it's like the the star is clearing a a path for itself announcing its its arrival to
the universe. In a way. Yes. It's a spectacular sight. It is. These herbig harrow objects can
stretch for light years carving carving their way through the nebula illuminating it with with
viagra colors. It's beautiful. It's like the universe is is putting on a fireworks display
to celebrate the birth of a of a new star. A cosmic celebration indeed. Yeah. And it's happening
all the time. What? In stellar nurseries across the galaxy. But the Orion cloud isn't just a
a birthplace for stars. That's right. It's also a graveyard. It's also a graveyard. A graveyard.
But we were just talking about about stellar nurseries. It's both within the Orion cloud.
You'll find remnants of stars that have already lived their lives and exploded as supernovas.
Right. One of the most striking features is something called Barad's Loop. Barad's Loop.
That name sounds sounds familiar. Yeah. What what is it? It's a it's a massive looping structure of
gas and dust. Okay. That was shaped by multiple supernova explosions over millions of years. So
the the shock waves from from those explosions sculpted the cloud into this into this loop.
Exactly. It's a testament to the immense power of of supernovae and how they can they can shape the
very structure of the galaxy. But but Barad's Loop isn't just a static structure. It's it's still
evolving. Okay. As new stars form within it. And the shock waves from past supernovae continue to
to ripple through the cloud. It's it's like a cosmic dance. It is. With creation and destruction.
Yeah. Constantly interacting and influencing each other. Beautifully put. The Orion cloud is a
dynamic. Yeah. Ever changing region of space. Right. A microcosm of the universe itself.
This has been an incredible journey so far. From our own sun to to giant stars and supernova
explosions. Yeah. Stellar nurseries and even even the possibility of of planets around. Yeah.
Around other stars. Yeah. We've we've covered so much ground. But but I know we're not done yet.
Right. What what else is in store for us in this in this deep dive into the world of stars.
Yeah. So we've talked about you know stars being born living their lives and eventually dying
sometimes in those in those spectacular supernova explosions. Right. But what happens after a
supernova. Yeah. What what's left behind. Well that depends on the mass of the star. Okay.
For smaller stars like our sun. Right. The the core collapses into a white dwarf. We we talked
about Sirius B earlier. Yeah. Which is a great example of a white dwarf. Right. Those incredibly
dense remnants about the size of Earth. Exactly. But what about what about those supergents the
ones that go supernova. What what happens to their cores. So for those massive stars the core
collapse is is much more violent. Okay. It can create a neutron star an even denser object packed
with neutrons. Okay. Imagine imagine cramming the mass of the sun into something the size of a city.
Okay. My mind is officially blown. Yeah. They're they're pretty incredible. A a teaspoon full of
neutron star material would weigh billions of tons. Right. You got it. Neutron stars are are
some of the most extreme objects in the universe. Wow. They have incredibly strong magnetic fields.
Yeah. And spin rapidly emitting beams of radiation that that sweep across space like a lighthouse.
We we detect these beams as pulsars. So those those rapidly flashing stars we sometimes see
are actually neutron stars. Exactly. Each flash is a is a pulse of radiation from the
rotating neutron star. Okay. It's it's like a cosmic beacon. Yeah. Sending out signals across
vast distances. That's amazing. But you mentioned that there's something even more extreme than a
than a neutron star. Right. What what happens when the core collapses so powerful that it it
goes beyond even a neutron star. That's when we get a black hole. Yeah. It's a region of space time
where gravity is so strong that nothing not even light can escape. Black holes are always a bit
mind boggling to me. Yeah. They're they're hard to wrap your head around. They're like like cosmic
vacuum cleaners sucking in everything that gets too close. Well that's that's a common misconception.
Black holes don't actually suck things in. Oh they have a strong gravitational pull. But it's
it's the same kind of gravity that keeps us on earth. Right. And the earth orbiting the sun. So
if I were to like get too close to a black hole I wouldn't I wouldn't get sucked in like spaghetti.
Not exactly. You would you would experience extreme tidal forces. Okay. That would stretch
you out. Okay. A process known as spaghettification. But it's it's the intense gravity. Yeah. That
would be the problem. Not any kind of sucking force. Okay. Well that's that's slightly reassuring
but still I think I'll keep my keep my distance from from black holes. I think that's a wise
decision. But but black holes are are an integral part of the universe that play a role in the
evolution of galaxies and the distribution of matter throughout space. It's amazing how everything
is is interconnected. It is. From the smallest particles to the to the largest structures in
the universe. Right. And it all goes back to to stars. They're the building blocks the engines
that that drive the evolution of the cosmos. Beautifully said. And this deep dive has has
only scratched the surface. Right. Of what we know about stars. There's there's still so much to
explore so many mysteries to unravel. I completely agree. And I have a feeling we'll be we'll be
revisiting the topic of stars many times in future episodes. I'm sure we will. Yeah. There's there's
always something new to discover something new to learn about these celestial wonders. Well this
deep dive has been a truly incredible journey. It has. We've we've learned about the diversity of
stars. Right. Their life cycles their dramatic deaths and and the remnants they they leave
behind. It's it's left me with a with a sense of awe and wonder about the the vastness and complexity
of the universe. And and that's what we we hope to inspire with Cosmos in a pod. A sense of curiosity
a desire to learn more about the cosmos and our place within it. Absolutely. So to our listeners
if you've enjoyed this journey through the world of stars be sure to follow and subscribe to Cosmos
in a pod. And don't forget to check out our YouTube channel for even more cosmic adventures.
As always we'd we'd love to hear from you. Absolutely. Leave us a review share your thoughts
on this episode and and let us know what cosmic mysteries you'd like us to explore next. So until
next time keep looking up keep asking questions and keep exploring the vast awe inspiring universe
around us. Clear skies.