Stellar Flares Near the Milky Way’s Black Hole

<v Speaker 1>Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
<v Speaker 1>with our soothing Bedtime Astronomie podcast. Each episode offers a
<v Speaker 1>gentle journey through the stars, planets, and beyond, perfect for
<v Speaker 1>unwinding after a long day. Let's travel through the mysteries
<v Speaker 1>of the universe as you drift off into a peaceful
<v Speaker 1>slumber under the night sky.
<v Speaker 2>Imagine, just for a moment, the absolute definition of isolation.
<v Speaker 2>I want you to close your eyes and just picture
<v Speaker 2>a place where the concept of hospitality doesn't even exist.
<v Speaker 3>Not even in the vocabulary, not at all.
<v Speaker 2>You are standing on a plateau of ice. It's two
<v Speaker 2>miles high, and the air is so thin it leaves
<v Speaker 2>you breathless just standing there. The temperature is hovering somewhere
<v Speaker 2>around I don't know, minus seventy maybe minus eighty degrees fahrenheit.
<v Speaker 3>And it is dark.
<v Speaker 2>And it's dark, not just nighttime dark, but a heavy, permanent,
<v Speaker 2>oppressive darkness that lasts for months on end. You are
<v Speaker 2>at the very bottom of the world.
<v Speaker 3>You're painting quite the visceral picture of the South Pole winter.
<v Speaker 3>It is physically speaking, probably the closest a human being
<v Speaker 3>can get to being on another planet without actually leaving
<v Speaker 3>Earth's orbit.
<v Speaker 2>It definitely feels that way, right that. Here's the paradox
<v Speaker 2>we're going to be wrestling with today. We're standing in
<v Speaker 2>this Ferzen silent, basically dead environment, but we aren't looking
<v Speaker 2>down at the ice. We're looking up. We're standing next
<v Speaker 2>to this massive machine, the South Pole Telescope or SPT,
<v Speaker 2>a ten meter wide dish that is just staring into
<v Speaker 2>the sky hunting for something.
<v Speaker 3>And it's certainly not hunting for peace and quiet.
<v Speaker 2>Far from it. That telescope shivering in the Antarctic cole Well, okay,
<v Speaker 2>the machine is fine. The humans are the ones shivering.
<v Speaker 2>It's focused on a region of space that is the
<v Speaker 2>polar opposite of where.
<v Speaker 3>It sits, literally the polar opposite.
<v Speaker 2>It's looking twenty six thousand light years away, directly at
<v Speaker 2>the center of our own galaxy, a place defined by heat, violin,
<v Speaker 2>chaotic gravity, and just unimaginable radiation.
<v Speaker 3>It's truly a tale of two extremes, isn't it. The
<v Speaker 3>coldest place on Earth is our best window for watching
<v Speaker 3>the hottest, most violent neighborhood in the Milky Way.
<v Speaker 2>And recently this telescope saw something. It wasn't just taking
<v Speaker 2>pretty pictures to put on tlendar. It caught a series
<v Speaker 2>of events, cataclysms really, that are changing how we understand
<v Speaker 2>the survival of stars near a super massive black hole.
<v Speaker 2>This is what we're exploring today, and it's all based
<v Speaker 2>on these incredible findings published in the Astrophysical.
<v Speaker 3>Journal, And it's really a detective story. It's about how
<v Speaker 3>we found these you could call them, screaming stars hiding
<v Speaker 3>behind a curtain of interstellar dust. And you know why
<v Speaker 3>we had to go to the literal end of the
<v Speaker 3>world just to hear them.
<v Speaker 2>So let's start with the mission. We aren't just here
<v Speaker 2>to say space is cool, though I mean it obviously
<v Speaker 2>is it is.
<v Speaker 3>That's a given.
<v Speaker 2>We're here to understand a specific discovery. What is the
<v Speaker 2>headline here? What did they find?
<v Speaker 3>The headline is that we have opened a new window.
<v Speaker 3>For decades, the center of our galaxy was it was
<v Speaker 3>like a locked room. We knew there was a monster
<v Speaker 3>inside the supermassive black hole Sagittarius A, but the door
<v Speaker 3>was blocked by this thick screen of dust.
<v Speaker 2>So you could hear things bumping around in there, but
<v Speaker 2>you couldn't see exactly.
<v Speaker 3>You could hear some knocking, maybe see a little bit
<v Speaker 3>of X ray light under the doorframe, but we couldn't
<v Speaker 3>actually see the action. The South Pole Telescope, using a
<v Speaker 3>very specific wavelength of light, just kicked the door.
<v Speaker 2>Down and what was inside.
<v Speaker 3>What it found inside was a population of stars undergoing
<v Speaker 3>these enormous magnetic eruptions, flares so violent they sort of
<v Speaker 3>defy our standard models of solar.
<v Speaker 2>Physics magnetic eruptions. That sounds intense. We're definitely going to
<v Speaker 2>unpack that mechanism in detail later, but before we get
<v Speaker 2>to the explosions themselves, I really want to understand the tool.
<v Speaker 2>We'll talk about the instrument. Why on Earth do you
<v Speaker 2>build a telescope in Antarctica?
<v Speaker 3>It is a very valid question. I mean, building a sensitive,
<v Speaker 3>multimillion dollar scientific instrument at the South Pole is a
<v Speaker 3>logistical nightmare.
<v Speaker 2>I can't even imagine.
<v Speaker 3>You can't just fly in a repair technician from Geek Squad.
<v Speaker 3>If a fuse blows in the middle of winter. The
<v Speaker 3>winter over crew is stuck there, completely isolated for six months.
<v Speaker 3>So why do it? Why go through all that trouble You.
<v Speaker 2>Mentioned when we were prepping for this, that it's all
<v Speaker 2>about water or more specifically, the lack of it.
<v Speaker 3>Precisely. To understand this, we have to talk a little
<v Speaker 3>bit about the electromagnetic spectrum. Light comes in many flavors.
<v Speaker 3>You know, you have the visible light, which are I.
<v Speaker 2>See, red, green, blue, all that exactly.
<v Speaker 3>Then you have high energy stuff like X rays and
<v Speaker 3>gamma rays, and low energy stuff like radio waves. The
<v Speaker 3>South Pole telescope operates in a very specific, very useful
<v Speaker 3>niche called millimeter wavelengths.
<v Speaker 2>Okay, so on the radio dial of the universe, where
<v Speaker 2>are we sitting with that.
<v Speaker 3>We're sitting right between infrared light, which you can think
<v Speaker 3>of as basically heat radiation, and traditional radio waves. We're
<v Speaker 3>talking about frequencies around ninety to one hundred and fifty gigahertz.
<v Speaker 3>Now here's the problem for astronomers on well most of
<v Speaker 3>the planet. Water molecules each two zero. They really really
<v Speaker 3>like to absorb light at these specific frequencies, eat the signal,
<v Speaker 3>They absolutely devour it. If you try to use a
<v Speaker 3>millimeter wave telescope in say Florida or even a temperate
<v Speaker 3>place like France, the humidity in the air would act
<v Speaker 3>like a brick wall.
<v Speaker 2>So it's like trying to listen to a concert from
<v Speaker 2>outside the stadium, but the walls are ten feet thick.
<v Speaker 3>That's a great analogy. The water vapor in the atmosphere
<v Speaker 3>would absorb all those beautiful signals coming from space before
<v Speaker 3>they ever reach your dish. You'd just be looking at
<v Speaker 3>noise from the atmosphere itself. It'd be like trying to
<v Speaker 3>stargaze through a thick, permanent fog bank.
<v Speaker 2>So you need a place where the air isn't just dry,
<v Speaker 2>it has to be bone dry.
<v Speaker 3>That's the term. Yes, and Antarctica is technically the largest
<v Speaker 3>desert on Earth because it is so profoundly cold, the
<v Speaker 3>air simply cannot hold moisture. The water freezes out of it.
<v Speaker 3>So the column of air directly above the south pole
<v Speaker 3>is incredibly stable and crucially incredibly transparent to these specific
<v Speaker 3>millimeter waves.
<v Speaker 2>So the extreme cold is actually a feature, not a bug.
<v Speaker 3>For this specific type of astronomy. The cold is the lens.
<v Speaker 3>It clears the fog, It provides a level of clarity
<v Speaker 3>that is basically unparalleled on the planet's surface. The only
<v Speaker 3>better place to put a telescope like this would be
<v Speaker 3>in space, which is, as you can imagine, significantly more expensive.
<v Speaker 2>I'm guessing just a little.
<v Speaker 3>Bit, a little bit.
<v Speaker 2>Yeah, Okay, so we've established that we're at the south
<v Speaker 2>pole to escape the water vapor. Now why do we
<v Speaker 2>care so much about millimeter waves? Why go through all
<v Speaker 2>this trouble to see in that specific frequency? Why not
<v Speaker 2>just use the Hubble or the James Web Space telescope.
<v Speaker 3>And that brings us to the curtain. The center of
<v Speaker 3>our galaxy is what twenty six thousand light years away.
<v Speaker 3>Between us and that center lies the main plane of
<v Speaker 3>the Milky Way, and it is filled with gas, debris
<v Speaker 3>and vast, vast clouds of interstellar dust.
<v Speaker 2>When you say dust, are we talking about the same
<v Speaker 2>stuff that's under my couch or is this something more exotic?
<v Speaker 3>Chemically it's not so different. You've got silicates, carbon, little
<v Speaker 3>bits of ice. But in space, over those kinds of distances,
<v Speaker 3>it acts like a smoke screen.
<v Speaker 2>Okay.
<v Speaker 3>Visible light, the kind that Hubble is famous foreseeing, has
<v Speaker 3>a very short wavelength. When that short wave of light
<v Speaker 3>hits a tiny dust particle, it bounces off or it
<v Speaker 3>gets absorbed. It scatters all over the place.
<v Speaker 2>Uh So it can't get through.
<v Speaker 3>It can't. If you look at the constellation Sagittarius toward
<v Speaker 3>the galactic center. With your naked eye or a normal telescope,
<v Speaker 3>you see these dark patches, these dark rifts. You're not
<v Speaker 3>actually seeing the core. You're seeing the shadow of the
<v Speaker 3>dust that's blocking the core.
<v Speaker 2>So visible light just hits the wall it gets blocked.
<v Speaker 3>It does. But milimeter waves are different. Their wavelength is
<v Speaker 3>much longer. Literally we measure it in millimeters, and this
<v Speaker 3>larger size allows them to well to sort of slip
<v Speaker 3>past the dust particles. They don't interact with the dust
<v Speaker 3>in the same way. They punch right through.
<v Speaker 2>I like the analogy of a forest. If I shoot
<v Speaker 2>a beaby gun into a really dense for or the bead,
<v Speaker 2>which represents the short wavelength of visible light, is going
<v Speaker 2>to hit a tree branch or a leaf almost immediately right.
<v Speaker 3>It's not getting far.
<v Speaker 2>But if I roll a bowling ball through that same forest.
<v Speaker 3>It's going to keep going. It might get deflected a little,
<v Speaker 3>but it's going to push through the underbrush. The millimeter
<v Speaker 3>waves are the bowling ball. They navigate the obstacle course
<v Speaker 3>of interstellar dust. So while an optical telescope sees a
<v Speaker 3>black wall of dust, the SBT sees right into the
<v Speaker 3>heart of the galaxy. It lifts the curtain.
<v Speaker 2>Okay, that makes perfect sense. So we have the location
<v Speaker 2>Antarctica to avoid water, and we have the wavelength millimeter
<v Speaker 2>to avoid dust. Now let's talk about the team and
<v Speaker 2>what they're actually looking for. This isn't just a guy
<v Speaker 2>with a joystick, right.
<v Speaker 3>Not at all. This is a massive collaboration led by
<v Speaker 3>researchers at the University of Illinois, Rabana Champagne and the
<v Speaker 3>National Center for Supercomputing Applications, and their methodology here is
<v Speaker 3>absolutely crucial. They weren't just taking a long exposure photograph,
<v Speaker 3>you know, static image. They were hunting for transience.
<v Speaker 2>Transience that sounds like people passing through a town. In astronomy,
<v Speaker 2>what does that mean In.
<v Speaker 3>The context of the sky. A transient is anything that
<v Speaker 3>changes brightness over a relatively short period. Most of the
<v Speaker 3>universe on a human timescale is well, it's pretty static.
<v Speaker 3>The SRUC tonight or the same brightness they were when
<v Speaker 3>the pyramids were built.
<v Speaker 2>More or less, they're constant.
<v Speaker 3>But a transient is a dynamic event. It's a flash,
<v Speaker 3>a pulse, an explosion, a flare, something that wasn't there yesterday.
<v Speaker 2>So they're looking for movies, not paintings.
<v Speaker 3>That's a perfect way to put it. Yes, they're looking
<v Speaker 3>for things that go bump in the cosmic night. And
<v Speaker 3>to do that, you can't just look once. You have
<v Speaker 3>to watch the same spot over and over and over again,
<v Speaker 3>comparing images, looking for a change. And that is exactly
<v Speaker 3>what the SPT did. It monitored the Galacted Center over
<v Speaker 3>multiple observing seasons, just waiting for a flicker in the
<v Speaker 3>millimeter band.
<v Speaker 2>And that waiting paid off, which brings us to the
<v Speaker 2>scene of the crime. Let's go to the destination and
<v Speaker 2>we're looking at the Galactic Center. Can you create a
<v Speaker 2>mental image for us if I could teleport to the
<v Speaker 2>neighborhood of Sagittarius A, What is the vibe? What does
<v Speaker 2>it feel like?
<v Speaker 3>Crowded and violent are the two words that come to
<v Speaker 3>mind immediately, and it's hard to overstate either of them. Okay, first,
<v Speaker 3>let's talk about the density in our neighborhood of the
<v Speaker 3>galaxy where the Sun lives. Space is profoundly empty. The
<v Speaker 3>nearest star to us, proximate centaury, is over four light
<v Speaker 3>years away.
<v Speaker 2>Which is an enormous distance.
<v Speaker 3>It's a staggering distance. Yeah, if the Sun were a
<v Speaker 3>great fruit in New York City, the nearest star would
<v Speaker 3>be another great food in San Francisco. That's the kind
<v Speaker 3>of emptiness we're.
<v Speaker 2>Used to, right, A lot of elbow room, spacious, comfortable.
<v Speaker 3>Very now in the galactic center, those grapefruits are all
<v Speaker 3>packed into the same stadium. The stellar density is millions
<v Speaker 3>of times higher than it is out here. Stars are
<v Speaker 3>everywhere you look, and because of the supermassive black hole
<v Speaker 3>at the center, they are all moving terrifyingly fast.
<v Speaker 2>And let's talk about the landlord of this stadium. Sagittarius,
<v Speaker 2>a star, sag a star as they call it, right, it's.
<v Speaker 3>The beast in the middle of it all. It has
<v Speaker 3>a mass of four million solar masses, four.
<v Speaker 2>Million times the mass of our sun.
<v Speaker 3>Yes, all of that gravitational pull compressed into a region
<v Speaker 3>smaller than the orbit of mercury. This absolutely dominates the environment.
<v Speaker 3>Stars aren't just drifting along in graceful orbits. They were
<v Speaker 3>being whipped around at thousands of kilometers per second. It
<v Speaker 3>is and this isn't an exaggeration, a cosmic demolition derby.
<v Speaker 2>And it's not just gravity that's the problem, right, The
<v Speaker 2>whole environment.
<v Speaker 3>Is messy, extremely messy. You have these powerful, tangled magnetic
<v Speaker 3>fields twisting through all the gas and plasma. You have
<v Speaker 3>shockwaves still propagating from ancient supernovae that went off nearby.
<v Speaker 3>You have intense scorching ultraviolet radiation from massive young stars
<v Speaker 3>that formed in that chaotic environment.
<v Speaker 2>So it's a terrible place to be a star.
<v Speaker 3>It's a terrible place to be anything. And on top
<v Speaker 3>of all that, you have the tidal forces from the
<v Speaker 3>black hole itself.
<v Speaker 2>Tidal forces. We hear that term a lot in science fiction. Captain,
<v Speaker 2>the tidal forces are tearing the ship apart. What does
<v Speaker 2>that actually mean in a physical sense.
<v Speaker 3>It's a great question, because it's a very real and
<v Speaker 3>powerful effect. It all comes down to the difference in
<v Speaker 3>the strength of gravity across an object. Gravity gets weaker
<v Speaker 3>with distance.
<v Speaker 2>Right the inverse square law exactly.
<v Speaker 3>So, if you are, say, falling feet first towards a
<v Speaker 3>black hole, the gravity pulling on your feet is much
<v Speaker 3>much stronger than the gravity pulling on your head. Because
<v Speaker 3>your feet are closer.
<v Speaker 2>It starts to stretch me.
<v Speaker 3>It stretches you violently. The technical term in extreme cases
<v Speaker 3>is bagetification. Now apply that to a giant ball of
<v Speaker 3>gas like a star. This means the black hole is
<v Speaker 3>constantly trying to pull the star into an oval, a
<v Speaker 3>football shape. It is squeezing and kneading.
<v Speaker 2>The star, eating it like dough precisely.
<v Speaker 3>And that constant mechanical needing adds an enormous amount of
<v Speaker 3>energy to the star. It turns up its interior, it
<v Speaker 3>drives convection currents, It creates turbulent heat and friction deep
<v Speaker 3>inside the star itself. It's not a peaceful existence.
<v Speaker 2>So you've got this crowded, high speed, high gravity, radiation
<v Speaker 2>soaked environment, and it's all hidden behind this thick curtain
<v Speaker 2>of dust, and the SPT is just watching it patiently.
<v Speaker 2>This leads us right to the discovery. What did they
<v Speaker 2>find in all that chaos?
<v Speaker 3>They found flares. But these weren't just any old standard
<v Speaker 3>solar flares. The paper describes them as powerful stellar flares
<v Speaker 3>that were so bright they were detectable in the millimeter
<v Speaker 3>band from twenty six thousand light years away.
<v Speaker 2>Okay, let's try and put that in perspective. I mean,
<v Speaker 2>our own sun has flares. How do these compare.
<v Speaker 3>It's almost not a fair comparison. If I let a
<v Speaker 3>mash in Los Angeles. You wouldn't see it in New York.
<v Speaker 3>The amount of energy you need to release to be
<v Speaker 3>visible across half the galaxy is it's incomprehensible.
<v Speaker 2>So these are not your garden variety flares.
<v Speaker 3>Not at all. The source material uses a comparison that
<v Speaker 3>I think is really effective. They make our Son's most
<v Speaker 3>dramatic outbursts look like flicker and candles. We were talking
<v Speaker 3>about energy releases that are many, many orders of magnitude
<v Speaker 3>stronger than anything we experience in our own solar system.
<v Speaker 2>There was a fascinating detail in the report about the
<v Speaker 2>images themselves, something about artifacts in the data. Can you
<v Speaker 2>explain that.
<v Speaker 3>Yes, this is a great detail for anyone who's into
<v Speaker 3>the tech side of this. The flares were so intense,
<v Speaker 3>so concentrated, that they completely saturated the detectors on the
<v Speaker 3>telescopes camera, so too much light, way too much. In
<v Speaker 3>the digital images. This overload created telltale diffraction spikes and
<v Speaker 3>vertical streaks. It's a lot like when you take a
<v Speaker 3>picture of the sun or a bright street light at
<v Speaker 3>night with your phone camera and you get those lines
<v Speaker 3>shooting out from the light source.
<v Speaker 2>Ah okay, I know exactly what you mean, it's.
<v Speaker 3>The same principle. The pixels, the little light buckets in
<v Speaker 3>the camera literally couldn't handle the fire hose of photons.
<v Speaker 3>The electual charge spilled over into the neighboring pixels. So
<v Speaker 3>finding these artifacts in the data was basically a smoking gun.
<v Speaker 3>It told the astronomers this isn't just random noise. This
<v Speaker 3>is a real point source of incredible power.
<v Speaker 2>And these weren't one off events. This wasn't just a
<v Speaker 2>single lucky shot. No.
<v Speaker 3>And that's a really key part of the study. They
<v Speaker 3>found about a dozen of these distinct events over the
<v Speaker 3>course of their survey. This implies that whatever is causing this,
<v Speaker 3>it's not a once in a billion year fluke. These
<v Speaker 3>stars are flaring regularly. It seems to be a chronic
<v Speaker 3>condition of living in that brutal neighborhood.
<v Speaker 2>Okay, so we have stars that are screaming, They're literally
<v Speaker 2>blasting out these enormous amounts of energy. The big question
<v Speaker 2>is how what is the physics here? What is the
<v Speaker 2>mechanism behind this?
<v Speaker 3>We believe the mechanism is a process called magnetic reconnection.
<v Speaker 2>Okay, I'm going to need this simple explanation on this one.
<v Speaker 2>Magnetic reconnection sounds like I'm fixing my Wi Fi router.
<v Speaker 3>It's a little bit more violent than that. I promise
<v Speaker 3>to understand this. You have to stop thinking of a
<v Speaker 3>star as just a solid ball of fire. A star
<v Speaker 3>is a fluid. It's made of plasma gas that's so
<v Speaker 3>hot the electrons have been ripped away from the atoms.
<v Speaker 2>It's a charged gas.
<v Speaker 3>It's a charge conducting gas. And because this plasma is
<v Speaker 3>constantly moving and churning, it generates incredibly powerful magnetic fields.
<v Speaker 3>The star is a giant, spinning fluid magnet.
<v Speaker 2>Okay, that makes sense, right, But.
<v Speaker 3>Here's the catch. Because the star is fluid, it doesn't
<v Speaker 3>spin like a solid ball. The equator of the star
<v Speaker 3>might spin faster than its poles. This is called differential rotation.
<v Speaker 2>So it's twisting itself up.
<v Speaker 3>It's twisting itself up exactly. The magnetic field lines, which
<v Speaker 3>are anchored deep inside the plasma, get dragged around by
<v Speaker 3>this uneven spinning. They get stretched and twisted and tangled
<v Speaker 3>up over time.
<v Speaker 2>I'm visualizing a big, messy ball of rubber bands.
<v Speaker 3>That is the perfect analogy. Imagine you're holding a bunch
<v Speaker 3>of rubber bands and you just keep twisting them. You're
<v Speaker 3>storing potential energy in that tangled mess. It gets tighter
<v Speaker 3>and tighter knots in Kink's form. Eventually the tension becomes
<v Speaker 3>too great for the rubber bands to hold. What happens snap,
<v Speaker 3>The rubber bands break and instantly release all that stored
<v Speaker 3>energy back into a simpler, lower energy shape. In a star,
<v Speaker 3>that snap is magnetic reconnection. The tangled magnetic field lines
<v Speaker 3>suddenly and violently reconfigure themselves into a simpler arrangement.
<v Speaker 2>And that process releases a ton of energy.
<v Speaker 3>An unbelievable amount of energy. In that instant of reconnection, particles, electrons,
<v Speaker 3>protons are accelerated to near the speed of light, and
<v Speaker 3>a massive blast of radiation is unleashed across the spectrum.
<v Speaker 2>And that's a solar flare.
<v Speaker 3>It is a solar flare. Now take that same basic mechanism,
<v Speaker 3>but put the star right next to a four million
<v Speaker 3>solar mass black hole.
<v Speaker 2>AH. The kneading, the tidal.
<v Speaker 3>Forces, the kneading, the tidal forces from Sagittarius A are
<v Speaker 3>constantly churning the interiors of these stars, twisting those magnetic
<v Speaker 3>fields much faster and much much tighter than a normal
<v Speaker 3>isolated star. Like our sun would ever experience.
<v Speaker 2>So the black hole is essentially winding up the rubber
<v Speaker 2>band ball for them, but winding it way tighter than
<v Speaker 2>the star could on its own.
<v Speaker 3>You've got it. It's super charging the magnetic dynamo. So
<v Speaker 3>when the snap of reconnection happens, it's not just a pop,
<v Speaker 3>it's a bomb. It releases a massive pulse of energy,
<v Speaker 3>and a significant portion of that energy comes out as
<v Speaker 3>millimeter wave radiation.
<v Speaker 2>The source also mentioned something called synchrotron radiation. Is that
<v Speaker 2>related to this whole process.
<v Speaker 3>It is directly related. Synchrotron radiation is the specific type
<v Speaker 3>of light that's produced in this scenario. It's what happens
<v Speaker 3>when charged particles. In this case, the electrons are moving
<v Speaker 3>at relativistic speeds near the speed of light, and they
<v Speaker 3>are forced to spiral around a magnetic field line. As
<v Speaker 3>they spiral, they scream out energy in the form of
<v Speaker 3>electromagnetic waves, and the signature of that process, the specific
<v Speaker 3>color of that light, is very strong in the radio
<v Speaker 3>and millimeter parts of the spectrum. The fact that the
<v Speaker 3>SPT saw these flares so clearly in millimeter waves is
<v Speaker 3>a huge conformation that this is the physical process at play.
<v Speaker 3>It tells us we were dealing with very high speed
<v Speaker 3>particles and very strong magnetic fields.
<v Speaker 2>So the whole chain of events lines up. The black
<v Speaker 2>hole distorts the star. That distortion tangles the star's magnetic fields.
<v Speaker 2>The fields snap in a reconnection event, particles get shot
<v Speaker 2>out at nearly the speed of light, and we see
<v Speaker 2>the resulting flash of synchrotron radiation in Antarctica.
<v Speaker 3>You just summarize a PhD thesis and a single sentence
<v Speaker 3>that is exactly the proposed chain of events.
<v Speaker 2>It's terrifying, but it's also it seems incredibly useful for astronomers.
<v Speaker 2>This leads us to the significance of all this. Why
<v Speaker 2>is this discovery being called a new window.
<v Speaker 3>It's significant for two main reasons, and they're both really important. First,
<v Speaker 3>it's about the method itself. Before this paper, we didn't
<v Speaker 3>really know for sure if we could use millimeter waves
<v Speaker 3>to effectively hunt for these stellar transients through all that dust.
<v Speaker 2>So this is a proof of concept.
<v Speaker 3>It absolutely is. It validates the tool and the technique.
<v Speaker 3>It means we can now start to look at other
<v Speaker 3>dust obscured regions of space, like the dense nurseries where
<v Speaker 3>new stars are born inside thick cloud of gas and dust,
<v Speaker 3>and we can watch for flares there too. It gives
<v Speaker 3>astronomers a whole new set of eyes.
<v Speaker 2>That's a huge deal.
<v Speaker 3>It is. Imagine you'd spent your whole life only able
<v Speaker 3>to hear. You'd know a lot about the world, but
<v Speaker 3>if you suddenly gain the abilities to see, your understanding
<v Speaker 3>of the world would expand infinitely. That is what malmeter
<v Speaker 3>wave of astronomy is starting to do for the study
<v Speaker 3>of these transient events.
<v Speaker 2>Okay, so that's the first reason.
<v Speaker 3>What's the second The second reason is what this discovery
<v Speaker 3>tells us about the stars themselves. The paper talks about
<v Speaker 3>the survivors.
<v Speaker 2>I love that term.
<v Speaker 3>It's so evocative, isn't it, Because that's what they are
<v Speaker 3>think about it. We can't see the surfaces of these
<v Speaker 3>stars directly. The duft is still too thick for a
<v Speaker 3>conventional telescope, but these incredibly powerful flares they act like probes.
<v Speaker 3>The paper compares each outburst to a brief lighthouse.
<v Speaker 2>Flash, a beacon in the dark.
<v Speaker 3>Precisely for a brief moment. That flare illuminates the fundamental
<v Speaker 3>physics of the star that produced it. By analyzing the
<v Speaker 3>light from the flare brightness, how it changes over time,
<v Speaker 3>its specific frequency, we can deduce things about the star's
<v Speaker 3>magnetic field strength, its plasma density, and its overall energetic state.
<v Speaker 2>So you're reading the star's biography by watching its temper tantrums.
<v Speaker 3>That's a fantastic way to put it. Yes, we're learning
<v Speaker 3>about the normal state of the star by studying it
<v Speaker 3>during its most extreme moments.
<v Speaker 2>So without the flare, the star is effectively invisible. The
<v Speaker 2>violence is the only reason we know it's there and what.
<v Speaker 3>It's like, and that is the profound irony at the
<v Speaker 3>heart of this discovery. If these stars were peaceful, stable
<v Speaker 3>and quiet, like our sun, they would be completely lost
<v Speaker 3>in the gloom of the galactic center. We would never
<v Speaker 3>be able to detect them through the dust. It is
<v Speaker 3>their violent struggle. They're kicking and screaming against the influence
<v Speaker 3>of the black hole that announces their existence to the
<v Speaker 3>rest of the universe.
<v Speaker 2>That's almost philosophical. It's like I flare there.
<v Speaker 3>Four am in the galactic center. Yes, it seems that
<v Speaker 3>survival is noisy, and it forces us to reconsider what
<v Speaker 3>we mean by a habitable or stable environment for a star.
<v Speaker 3>These stars are proving that existence is possible even when
<v Speaker 3>you're living in the teeth of a monster.
<v Speaker 2>So what does this discovery mean for the big picture?
<v Speaker 2>Let's talk about the implications. We're trying to build a
<v Speaker 2>complete model of our galaxy, right, how does this new
<v Speaker 2>information slot.
<v Speaker 3>Into that It slots in by helping us understand the
<v Speaker 3>ecology of galactic cores. For a long time, we sort
<v Speaker 3>of thought of the center as just a graveyard, a
<v Speaker 3>place where things go to get eaten by the black hole,
<v Speaker 3>a final.
<v Speaker 2>Destination right the end of the line.
<v Speaker 3>But this research and others like it, shows that it's
<v Speaker 3>a dynamic, active ecosystem. Stars are surviving there, they're interacting,
<v Speaker 3>they're evolving, and they're flaring. It's a habitat, just a
<v Speaker 3>very very extreme one. Understanding which tys of stars can
<v Speaker 3>survive there and how they do it is a huge
<v Speaker 3>piece of the puzzle of galactic evolution.
<v Speaker 2>And does this help us understand other galaxies too? Oh?
<v Speaker 3>Absolutely, that's one of the main goals. Nearly every large
<v Speaker 3>galaxy we think has a supermassive black hole at its center,
<v Speaker 3>can't see the individual stars in the centers of other
<v Speaker 3>galaxies with this level of detail, they're just too far away.
<v Speaker 3>So Sagittari s A is our local laboratory.
<v Speaker 2>It's our petri dish.
<v Speaker 3>It's our petri dish. If we can understand the exotic
<v Speaker 3>physics of stars surviving here in our own backyard, we
<v Speaker 3>can then apply those models to understand what's happening in
<v Speaker 3>things like quasars and other active galactic nuclei that we
<v Speaker 3>see lighting up the distant universe.
<v Speaker 2>So looking forward, what are the next steps? What happens now?
<v Speaker 3>More data, always more data. The SPT is continuing its
<v Speaker 3>survey and similar telescopes are also watching. We want to
<v Speaker 3>build up a much larger catalog of these events. We
<v Speaker 3>want to know do these flares have a pattern? Are
<v Speaker 3>they periodic?
<v Speaker 2>You mean like does a certain starflare every forty days
<v Speaker 2>or is it completely random?
<v Speaker 3>Exactly? If we found a periodicity, that would tell us
<v Speaker 3>something profound about the stars orbit or its internal magnetic cycle.
<v Speaker 3>And a huge question is are there different types of
<v Speaker 3>stars involved?
<v Speaker 1>Right?
<v Speaker 2>Is it only the massive, young blue stars that are
<v Speaker 2>doing this or can old, smaller red dwarfs flare like
<v Speaker 2>this too when they're in that environment.
<v Speaker 3>We need a census, We need to figure out the
<v Speaker 3>demographics of this flaring population. And the other big step
<v Speaker 3>forward is what's often called multi messenger astronomy.
<v Speaker 2>That's the big buzzword in the field right now. It's
<v Speaker 2>about connecting the dots between different kinds of observations.
<v Speaker 3>It is the dream scenario. Is this the SPT in Antarctica,
<v Speaker 3>spots of flare in millimeter waves, It instantly and automatically
<v Speaker 3>sends an alert to say, the Chandra X ray observatory
<v Speaker 3>in orbit, and maybe some radio telescopes on the ground.
<v Speaker 3>The message says, hey, look at coordinate X right now,
<v Speaker 3>something is happening.
<v Speaker 2>So you get all these different instruments looking at the
<v Speaker 2>same event at the same.
<v Speaker 3>Time, at the same time. And if we can catch
<v Speaker 3>a flare in millimeter woes and X rays and radio
<v Speaker 3>waves simultaneously, we get a complete three D picture of
<v Speaker 3>the physics. We see the particle acceleration from the millimeter
<v Speaker 3>waves and the extreme thermal heating of the plasma from
<v Speaker 3>the X rays. It would be a complete blueprint of
<v Speaker 3>the explosion.
<v Speaker 2>That's the dream scenario.
<v Speaker 3>Total wavelength coverage that is where the entire field is heading,
<v Speaker 3>real time coordination between telescopes on the ice, on mountains,
<v Speaker 3>and in space it requires this incredible level of global
<v Speaker 3>and I guess orbital cooperation.
<v Speaker 2>It really highlights how interconnected modern science has become. I mean,
<v Speaker 2>you have people sleeping in parkas at the South Pole
<v Speaker 2>who can trigger an observation on a multi billion dollar
<v Speaker 2>satellite controlled by a team in Cambridge, Massachusetts, all.
<v Speaker 3>To catch a flicker from a star whose light has
<v Speaker 3>been traveling for twenty six thousand years, a star that
<v Speaker 3>might not even exist anymore.
<v Speaker 2>Well, twenty six thousand years ago, it existed with a vengeance.
<v Speaker 3>That's a fair point. We are, in a very real
<v Speaker 3>sense watching history.
<v Speaker 2>Unfold, so let's try to wrap this all up. We've
<v Speaker 2>taken this incredible journey from the frozen plateau of Antarctica
<v Speaker 2>to the fiery core of the Milky Way. We've learned
<v Speaker 2>about bone, dry air, millimeter windows, and this violent process
<v Speaker 2>of magnetic reconnection, and.
<v Speaker 3>We see that the universe is far more dynamic and
<v Speaker 3>violent than our quiet night sky might suggest. We've learned
<v Speaker 3>that what looks like empty space to our eyes is
<v Speaker 3>actually teeming with this high energy drama.
<v Speaker 2>I want to leave everyone with that final thought you
<v Speaker 2>brought up about the lighthouse. I think it's the most
<v Speaker 2>powerful and sticky idea from this whole conversation.
<v Speaker 3>It really is a powerful metaphor.
<v Speaker 2>We usually equate destruction with loss. We think of explosions
<v Speaker 2>and cataclysms as endings, but in this specific case, in
<v Speaker 2>the darkest, dustiest, most dangerous part of our entire galaxy,
<v Speaker 2>it is the violence itself that allows us to see
<v Speaker 2>the destruction is what creates the signal.
<v Speaker 3>Without those flares, the stars would just be invisible ghosts,
<v Speaker 3>lost behind the curtain.
<v Speaker 2>Exactly if those stars were peaceful and quiet, they'd be
<v Speaker 2>hidden from us forever. It's their constant struggle they're kicking
<v Speaker 2>and screaming against the black hole's gravity that announces their
<v Speaker 2>existence across thousands of light years.
<v Speaker 3>It really does suggest that in the cosmos, discovery and
<v Speaker 3>destruction are often two sides at the same coin. We
<v Speaker 3>learn the most about the universe when things are at
<v Speaker 3>their most extreme, when they're breaking.
<v Speaker 2>So the next time you're out on a clear night
<v Speaker 2>and you look up at the milky Way, that faint,
<v Speaker 2>cloudy strip across the sky, just remember what's really happening
<v Speaker 2>in the galactic downtown district. It's not just a soft glow.
<v Speaker 2>It's a demolition derby, And there are eyes in the
<v Speaker 2>ace at the bottom of the world, watching it all happen.
<v Speaker 3>And finding more all the time. Keep watching the past,
<v Speaker 3>da