Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomie podcast. Each episode offers a
Speaker 1: gentle journey through the stars, planets, and beyond, perfect for
Speaker 1: unwinding after a long day. Let's travel through the mysteries
Speaker 1: of the universe as you drift off into a peaceful
Speaker 1: slumber under the night sky.
Speaker 2: I want you to just close your eyes for a second. Well,
Speaker 2: assuming you aren't driving or operating heavy machinery, right.
Speaker 3: Yeah, please keep your eyes open if you're behind the.
Speaker 2: Wheel exactly, but if you can, I want you to
Speaker 2: imagine that you are standing at the exact center of
Speaker 2: our galaxy, the Milky Way.
Speaker 3: Which is an incredibly hostile place to imagine yourself.
Speaker 2: By the way, Oh, it's terrifying. You aren't looking up
Speaker 2: at some peaceful, twinkling night sky from a quiet suburban
Speaker 2: backyard in the Orion spur right, not at all. You
Speaker 2: are completely surrounded by an environment so dense and like,
Speaker 2: so utterly chaotic and violently dynamic that it practically defies
Speaker 2: human comprehension.
Speaker 3: It really is like a cosmic mosh pit out there.
Speaker 2: That's the perfect way to describe it. You've got millions
Speaker 2: of massive stars packed into a volume of space where
Speaker 2: you know, we might only see one or two stars
Speaker 2: around our own sun.
Speaker 3: And if you had eyes that could see across the
Speaker 3: entire electromagnetic spectrum, the radiation would just be absolutely blinding.
Speaker 2: Right, and the gravitational forces are pulling, twisting, and warping
Speaker 2: literally everything in sight. And right there, anchoring this entire
Speaker 2: terrifyingly beautiful merry go round is Sagittarius.
Speaker 3: A, our residence super massive black hole.
Speaker 2: Yeah, the one packing the mass of four million of
Speaker 2: our suns into a space that I think could easily
Speaker 2: fit inside the orbit of Mercury right roughly.
Speaker 3: Yes, it really is the ultimate extreme environment.
Speaker 2: It's wild.
Speaker 3: It is because it is so easy for us down
Speaker 3: here on Earth to think of a black hole as
Speaker 3: just you know, a dark, empty void sitting in the
Speaker 3: middle of nowhere, ye leave, vacuuming things.
Speaker 2: Up like a giant's space stream, exactly like a drain.
Speaker 3: Yeah. But the reality of Sagittarius A, or sgr A
Speaker 3: as we usually call it, is that the area immediately
Speaker 3: surrounding it is anything but empty. It is essentially a
Speaker 3: natural laboratory for us It lets us witness first hand
Speaker 3: exactly how matter behaves when it's pushed to the absolute
Speaker 3: limits of physics.
Speaker 2: Right on the doorstep of this thing, Right on.
Speaker 3: The doorstep where the gravity is so intense that not
Speaker 3: even light can escape once it crosses that event horizon,
Speaker 3: we are watching extreme physics play out in real time.
Speaker 2: Okay, let's unpack this because for the last twenty years
Speaker 2: or so, astronomers have been staring into this specific natural laboratory,
Speaker 2: peering through all the dust and the glare, and they've.
Speaker 3: Been completely baffled by a mystery.
Speaker 2: A cosmic who do nit? Basically because they have been
Speaker 2: watching these very mysterious, highly compact clouds of glowing gas
Speaker 2: that are actively circling and feeding the super massive black hole.
Speaker 3: Right, little glowing gas clouds.
Speaker 2: Nobody knew where they came from. They were just out
Speaker 2: there braving the extreme gravity, acting like these perfectly timed
Speaker 2: appetizers for the black hole.
Speaker 3: It's a remarkable detective story, honestly.
Speaker 2: It really is. And today we are going to trace
Speaker 2: the exact origin of these enigmatic gas clouds. We're going
Speaker 2: back to the scene of the crime to understand the
Speaker 2: incredible stellar mechanics that are cooking up these celestial meals.
Speaker 3: And the challenge here is just monumental because you know,
Speaker 3: if you are trying to observe the galactic center from Earth,
Speaker 3: you were looking through twenty six thousand light years of
Speaker 3: interstellar dust.
Speaker 2: Twenty six thousand light years.
Speaker 3: Yeah, dust, debris, intervening gas. Yeah, You're not just pointing
Speaker 3: a backyard telescope at the sky and snapping a clear
Speaker 3: photograph of what's happening.
Speaker 2: Right, You're looking through basically a galactic fog.
Speaker 3: A very thick fog. The clues are heavily obscured, the
Speaker 3: environment itself is incredibly hostile, and the objects we are
Speaker 3: tracking are well on a cosmic scale, vanishingly.
Speaker 2: Small, elusive little things.
Speaker 3: Very elusive. To actually figure out where these specific clouds
Speaker 3: of gas originated, you have to peel back multiple layers
Speaker 3: of complex astrophysics.
Speaker 2: And use some crazy advanced technology, which we'll get into. Well,
Speaker 2: let's start with the victims, or maybe of the suspects,
Speaker 2: depending on how you look at the crime scene, the
Speaker 2: g cloud family, the G cloud family. Now, looking back
Speaker 2: at the records, astronomers had noticed anomalies in the center
Speaker 2: of the galaxy for a while but things really kicked
Speaker 2: off with a major discovery back in twenty twelve.
Speaker 3: Right, that's right, Using some seriously advanced infrared observations teams
Speaker 3: spotted these compact gas clouds hanging out uncomfortably close to SGRA.
Speaker 2: Uncomfortably close is a good way to put it. And
Speaker 2: the most famous one, the one that really made the
Speaker 2: mainstream scientific headlines back then, is called G two, Yes,
Speaker 2: G two, And to give you the listener a sense
Speaker 2: of what we are actually dealing with here, G two
Speaker 2: isn't like the size of a star. It contains roughly
Speaker 2: the mass of three earths, which.
Speaker 3: Is tiny for an astronomical.
Speaker 2: Object, minuscule, and the data shows it emits this very
Speaker 2: specific light signature from hydrogen and helium, which tells us
Speaker 2: we're dealing with a hot, dusty cloud of gas, not
Speaker 2: a solid, rocky planet.
Speaker 3: Right. And what's fascinating here is that G two is
Speaker 3: not just a random, formless fog drifting aimlessly through space like.
Speaker 2: You'd normally picture a gas cloud.
Speaker 3: Exactly when we picture gas in space, we usually think
Speaker 3: of a nebula of vast diffuse, very static, but G
Speaker 3: two is a highly cohesive, trackable entity. It behaves almost
Speaker 3: like a solid body in terms of its orders a path,
Speaker 3: and that path is incredibly elongated or eccentric.
Speaker 2: So it's not a nice, clean circle.
Speaker 3: Far from it. It moves through this extreme gravitational field,
Speaker 3: accelerating to thousands of kilometers per second as it swings
Speaker 3: near the black hole. Wow, it acts almost like a
Speaker 3: glowing tracer dye dropped into a rushing river. By watching
Speaker 3: how G two moves and how its shape stretches over time,
Speaker 3: astronomers can map the invisible gravitational.
Speaker 2: Currents swirling around the supermassive black hole. That is so cool.
Speaker 2: But wait, surviving near a black hole isn't a exactly
Speaker 2: a walk in the park, not at all. And this
Speaker 2: is the part of the data that really made me
Speaker 2: do a double take. How does a cloud of gas
Speaker 2: which is just loosely associated atoms right.
Speaker 3: Essentially yes, held together by extremely weak gravity?
Speaker 2: Right? So how does it maintain any sort of compact
Speaker 2: shape when it's subjected to the monumental tidal forces of
Speaker 2: a super massive black hole.
Speaker 3: It's a great question.
Speaker 2: Shouldn't the black hole's gravity just, I don't know, shred
Speaker 2: it instantly the moment it gets close.
Speaker 3: Well, that survival mechanism was the central puzzle for years
Speaker 3: following the twenty twelve discovery because the tidal forces near
Speaker 3: SGRA are just beyond immense.
Speaker 2: You can't even imagine.
Speaker 3: To conceptualize this, imagine you are falling feet first toward
Speaker 3: a black hole.
Speaker 2: Okay, slightly terrifying, but I'm with you.
Speaker 3: The gravity pulling on your feet is significantly stronger than
Speaker 3: the gravity pulling on your head, simply because your feet
Speaker 3: are physically closer to the center of mass.
Speaker 2: Right, makes sense.
Speaker 3: So that difference in gravitational pull that gradient. It stretches
Speaker 3: you out vertically while simultaneously compressing you horses wou. In astrophysics,
Speaker 3: we literally call this process spaghetification.
Speaker 2: I always love that term. I mean, it sounds like
Speaker 2: something out of a cartoon, but it really describes one
Speaker 2: of the most terrifying ways to be destroyed in the universe.
Speaker 3: It is a brilliantly descriptive term. Now apply that same
Speaker 3: mechanical stretching to a relatively small cloud of gas like
Speaker 3: G two.
Speaker 2: Okay, so it's getting spaghettified exactly. Yeah.
Speaker 3: As G two plunges into the deepest part of the gravity, well,
Speaker 3: the front of the cloud is being pulled significantly faster
Speaker 3: than the back of the cloud. Right, according to classical physics,
Speaker 3: it should smear out entirely into a long, thin, invisible
Speaker 3: wisp of atoms. It should lose all its structure, but
Speaker 3: it doesn't. Well, it does stretch. Observations show it has
Speaker 3: this faint, elongated trailing tail that astronomers creatively named G
Speaker 3: two t.
Speaker 2: Ah G two tail. Very creative, right, But the.
Speaker 3: Core of the cloud itself has remained surprisingly stubbornly compact.
Speaker 3: It is held together and remained visible much longer than
Speaker 3: a simple puff of gas should.
Speaker 2: That is so weird. And the very fact that we
Speaker 2: see the bright emission lines of hydrogen and helium means
Speaker 2: this gas is hot, right.
Speaker 3: Extremely hot. It is being energized and ionized by the
Speaker 3: intense ambient radiation of the environ which.
Speaker 2: Is why it glows so brightly in the infrared spectrum
Speaker 2: even as it's getting stretched out.
Speaker 3: Exactly.
Speaker 2: Okay, So if I'm picturing this right, it's like a
Speaker 2: cosmic comet, but instead of a solid rock made of
Speaker 2: ice and dirt, it's a blob made entirely of glowing
Speaker 2: hot dust and gas.
Speaker 3: Yes, a very hot blob, just.
Speaker 2: Dragging this faint tail G two t behind it as
Speaker 2: it races at blinding speeds around this massive gravitational sinkhole.
Speaker 3: That's a perfect visual in Just when people.
Speaker 2: Were scratching their heads over G two trying to figure
Speaker 2: out how it was surviving spaghettification, some researchers went back
Speaker 2: in mind the old archival.
Speaker 3: Data, which is often where the best discoveries hide, truly,
Speaker 3: and what they found completely shifted the paradigm.
Speaker 2: G two wasn't a lone wolf.
Speaker 3: No, it wasn't king In the.
Speaker 2: Data from years prior, they found an earlier, nearly identical cloud.
Speaker 2: They retroactively named it G one, and it was traveling
Speaker 2: on a strikingly similar orbit just further ahead.
Speaker 3: Finding G one was the absolute turning point in this investigation.
Speaker 2: Really, why is that so crucial?
Speaker 3: Because the moment you find multiple distinct objects on nearly
Speaker 3: identical trajectories in astronomy, you have to stop thinking about
Speaker 3: them as isolated anomalies. Oh, I see a single cloud
Speaker 3: of gas surviving near a black hole. Could just be
Speaker 3: a fluke, maybe a star that had its outer layer
Speaker 3: script or a random collision.
Speaker 2: Just a weird coincidence.
Speaker 3: Right, But two distinct clouds plus a trailing tail, all
Speaker 3: following the exact same, highly eccentric path through the single
Speaker 3: most chaotic environment in the galaxy. That's a pattern exactly.
Speaker 3: It implies a much larger system. It strongly implies a
Speaker 3: shared origin or an ongoing mechanism actively producing these objects
Speaker 3: in a.
Speaker 2: Sequence, which brings us to the underlying structure connecting them all.
Speaker 2: Because it became clear that these aren't just isolated clumps
Speaker 2: of gas floating independently in the dark.
Speaker 3: The plot thickens significantly here.
Speaker 2: It really does, because recently observers noticed that gas from
Speaker 2: G two's tail that stretched out G two T section
Speaker 2: has actually condensed into a third distinct clump.
Speaker 3: Yes, another clump formed.
Speaker 2: Now, if you are a logical person, you'd assume the
Speaker 2: astronomical community would name this new clump G three. You
Speaker 2: would think so, But no, when you dig into the literature,
Speaker 2: you find out they had already used the name G
Speaker 2: three for an entirely different, unrelated object somewhere else in
Speaker 2: the galactic center.
Speaker 3: Yeah, astronomical naming conventions can be a bit of a nightmare.
Speaker 2: It's a whole separate mystery. We've got telescopes literally called
Speaker 2: the extremely large telescope, and then we have overlapping designations
Speaker 2: for gas clouds. We do our best, so for the
Speaker 2: sake of clarity, we'll just refer to it as the
Speaker 2: third clump. But naming aside. The realization here is profound
Speaker 2: G one, G two, and this third clump they form.
Speaker 3: A streamer one one two three streamer.
Speaker 2: Right. It's not a set of distinct pearl like clouds
Speaker 2: on a string. It's a coherent, continuous flowing river of
Speaker 2: material moving straight through the heart of the galactic center.
Speaker 3: And that shift from viewing these as individual objects to
Speaker 3: viewing them as a continuous streamer fundamentally changes how we
Speaker 3: model the physics of the region. How So well, when
Speaker 3: we use words like clumps or clouds, we naturally picture discrete,
Speaker 3: self contained objects, perhaps held together by their own internal gravity,
Speaker 3: like giant gaseous asteroids.
Speaker 2: Yeah, that's exactly what I was picturing, little floating blobs.
Speaker 3: But the fluid dynamics of this newly identified streamer suggests
Speaker 3: something entirely different. The gas in this massive cosmic river
Speaker 3: isn't flowing at a uniform density, is highly turbulent. It
Speaker 3: has natural fluctuations and instabilities as the river flows, sometimes
Speaker 3: the gas compresses slightly, pushing the atoms closer together.
Speaker 2: And sometimes it thins out, I guess.
Speaker 3: Exactly, into wider or less dense streams. And the reason
Speaker 3: we see these distinct visual clumps like G one and
Speaker 3: G two while the rest of the river remains largely invisible.
Speaker 2: To it, right, the rest of it is invisible.
Speaker 3: Mostly yes, And it comes down entirely to the specific
Speaker 3: physics of how ionized gas emits light in these extreme conditions.
Speaker 2: Ah okay, I want to dig into that physics because
Speaker 2: it clears up a massive misconception. The brightness of these clouds,
Speaker 2: the infrared light they shoot at our telescopes. It doesn't
Speaker 2: increase on a linear scale, right, No, it doesn't. The
Speaker 2: physics dictates that the brightness increases with the square of
Speaker 2: their density. So if the density of a patch of
Speaker 2: gas doubles, it doesn't get twice as bright. It gets
Speaker 2: four times as bright.
Speaker 3: That's right.
Speaker 2: It scales with the square, and if it triples, it
Speaker 2: gets nine times as bright. So let me make sure
Speaker 2: I'm wrapping my head around this. It's not actually a
Speaker 2: string of separate solid pearls floating in space at all.
Speaker 2: At all, it is literally just one continuous river. But
Speaker 2: because of that squared relationship, the areas where the gas
Speaker 2: compresses even just a little bit, like rapids and terrestrial
Speaker 2: river suddenly light up like a neon sign.
Speaker 3: That is a fantastic way to conceptualize it. The rapids
Speaker 3: analogy perfectly captures the fluid dynamics happening on a cosmic scale.
Speaker 3: Here we are dealing with continuous flowing matter. When the
Speaker 3: gas in this stream compresses, maybe due to internal turbulence
Speaker 3: or subtle gravitational interactions along its path, the density spikes,
Speaker 3: the local density spikes, and because the emission brightness scales
Speaker 3: with the square of the density, a section of the
Speaker 3: river that is just moderately denser than the surrounding flow
Speaker 3: suddenly crosses a visibility threshold.
Speaker 2: So it just pops out of the darkness exactly.
Speaker 3: It becomes vastly brighter, illuminating that specific compressed knot of
Speaker 3: gas against the pitch black background of empty space.
Speaker 2: That is wild.
Speaker 3: It's largely an optical effect driven by the thermodynamics of
Speaker 3: the emission process. So what astronomers have been calling the
Speaker 3: distinct g clouds for.
Speaker 2: The last decade are really just the rapids.
Speaker 3: Yes, just the most compressed, highly illuminated rapids in a
Speaker 3: continuous flowing river of gas that is steadily winding its
Speaker 3: way towards SAGITTARIUSA.
Speaker 2: Okay, so we have this picture now, a glowing, clumpy
Speaker 2: river of hot plasma flowing relentlessly toward the supermassive black hole.
Speaker 3: A majestic, terrifying river truly.
Speaker 2: But the obvious question, if you are looking at the
Speaker 2: ecosystem of the galaxy is what does this river actually
Speaker 2: do to the black hole itself? It feeds it, right,
Speaker 2: because black holes aren't just static sinkholes. They have to eat.
Speaker 2: They sustain their immense mass by accreting matter, and right
Speaker 2: here we have a literal river of matter flowing right
Speaker 2: to its front door.
Speaker 3: This river provides the fundamental fuel for the black hole's
Speaker 3: current state. And what's critical to understand here isn't just
Speaker 3: the existence of the fuel, but the specific volume and
Speaker 3: rate of that delivery.
Speaker 2: The portion sizes basically.
Speaker 3: Exactly when the astrophysics teams ran the complex hydrodynamical calculations
Speaker 3: on this G one two three streamer, they calculated the
Speaker 3: mass of just one of these highly visible glowing clumps.
Speaker 2: What did they find.
Speaker 3: We are talking about roughly one earth mass of gaseous
Speaker 3: material falling down toward the black Holes accretion zone every decade.
Speaker 2: Let's put that in perspective, because here is where it
Speaker 2: gets really mind bending. One Earth mass every ten years.
Speaker 3: It sounds big to us, but.
Speaker 2: Right in the cosmic scheme of things, an Earth mass
Speaker 2: is practically nothing. The Sun alone is over three hundred
Speaker 2: thousand times more massive than the Earth.
Speaker 3: It's a tiny snack.
Speaker 2: A microscopic snack. But imagine taking our entire planet, all
Speaker 2: the oceans, the mountains, the core, mashing it down into
Speaker 2: a giant, cohesive meat ball of hot gas, and dropping
Speaker 2: it straight into a black hole once every decade, like clockwork.
Speaker 3: It's a very specific dietary routine.
Speaker 2: It's this highly precise, agonizingly slow droop feeding schedule. And
Speaker 2: what's wild to me looking at the data is that
Speaker 2: this relatively tiny intermittent meal is exactly what Sagittarius A
Speaker 2: needs right now.
Speaker 3: The precise matching of that supply to the black holes
Speaker 3: demand is the key insight here. Sagittary's A is currently
Speaker 3: what astrophysicists would classify as a remarkably quiet, almost starved,
Speaker 3: supermassive black hole starved. Really, Yes, If you look deep
Speaker 3: into the universe at other galaxies, you frequently see quasars.
Speaker 3: These are super massive black holes that are actively consuming
Speaker 3: colossal amounts of entire stars and massive gas clouds at
Speaker 3: an incredible rate.
Speaker 2: Just gorging themselves.
Speaker 3: Gorging. They generate so much friction, heat, and radiation in
Speaker 3: their accretion discs that the area immediately surrounding the black
Speaker 3: hole can outshine all the billions of stars in their
Speaker 3: host galaxy combined.
Speaker 2: That is horrifying. But our black hole isn't doing that.
Speaker 3: No, our black hole is doing absolutely nothing of the sort.
Speaker 3: It is in a low rumble, nearly dormant state.
Speaker 2: Okay, so the earth size meatball every ten years, that.
Speaker 3: Calculated dietary requirement of one Earth mass per decade derived
Speaker 3: from the g clouds perfectly aligns with the current incredibly
Speaker 3: quiet energy output of.
Speaker 2: SGRA, just enough to keep it ticking exactly.
Speaker 3: It's just enough material crossing the event horizon and to
Speaker 3: keep the engine simmering, maintaining its low level X ray
Speaker 3: and infrared flickering, but not nearly enough to ignite it
Speaker 3: into a raging quasar.
Speaker 2: So this little river of glowing gas isn't just some
Speaker 2: random curiosity floating by. It is quite literally the primary
Speaker 2: life support system keeping our galaxies central super massive black
Speaker 2: hole actively ticking right now.
Speaker 3: Yes. Furthermore, identifying this specific streamer solves a massive, long
Speaker 3: standing mechanical problem in astrophysics regarding how black holes actually
Speaker 3: feed in the first place.
Speaker 2: Because they don't just suck everything up magically.
Speaker 3: Right right. The general public often thinks of black holes
Speaker 3: as cosmic vacuum cleaners that just possess an infinite inescapable suction,
Speaker 3: dragging in everything regardless of distance.
Speaker 2: Like a giant hoover in space exactly.
Speaker 3: But mechanically speaking, getting matter to actually fall into a
Speaker 3: black hole crossing the event horizon rather than just orbiting
Speaker 3: around it endlessly is incredibly.
Speaker 2: Difficult because gravity is a two ways stream.
Speaker 3: Gravity is a two way street, and orbital mechanics are stubborn.
Speaker 2: Right. It's because of angular momentum. It's the exact same
Speaker 2: reason the Earth just keeps spinning around the Sun year
Speaker 2: after year instead of plunging into it. Precisely, we are
Speaker 2: being pulled by the Sun's gravity, sure, but we are
Speaker 2: moving too fast sideways that sideway's momentum keeps us locked
Speaker 2: in a stable orbit. To fall in, we would have
Speaker 2: to hit the brakes.
Speaker 3: That sideways motion is the fundamental barrier to black hole feeding.
Speaker 3: For matter to fall into the event horizon, it has
Speaker 3: to lose a massive amount of that sideway's motion.
Speaker 2: It have to shed its angular momentum.
Speaker 3: And dissipate its kinetic energy. Usually in a standard galactic model,
Speaker 3: this happens via an accretion.
Speaker 2: Disc swirling disk of doom we always see in movies.
Speaker 3: Right, gas and dust are drawn toward the black hole,
Speaker 3: but because of their angular momentum, they settle into a massive,
Speaker 3: flattened swirling disc. Inside that disc, particles constantly rub against
Speaker 3: each other, creating immense.
Speaker 2: Friction, and friction creates heat.
Speaker 3: Exactly that friction generates heat, and in the process the
Speaker 3: matter loses energy. Only as its shed energy can it
Speaker 3: slowly gradually spiral inward.
Speaker 2: Like circling a drain, very very slowly.
Speaker 3: This process can take millions of years from material at
Speaker 3: the outer edge of the disk to actually reach the center.
Speaker 3: But the geometry of the G one two three streamer
Speaker 3: acts as a direct high speed delivery system because it's.
Speaker 2: Not settling into a nice, polite circular disc. It's diving
Speaker 2: straight in exactly.
Speaker 3: The highly elongated plunging orbit of this specific gas river
Speaker 3: means the material doesn't have to spend a million years
Speaker 3: slowly spiraling through a crowded accretion disk. It gets to
Speaker 3: ship the line. Yes, it is already on an extreme
Speaker 3: trajectory that takes it incredibly close to the black hole
Speaker 3: at its closest approach or periapsis.
Speaker 2: Wow.
Speaker 3: It dives in so steeply that it allows the extreme
Speaker 3: tidal forces of the black hole to physically strip the
Speaker 3: material away from the mainstream and feed it directly into
Speaker 3: the inner accretion zone.
Speaker 2: So understanding this specific, highly efficient fuel source is truly
Speaker 2: the golden ticket to understanding the current quiet state of
Speaker 2: our galaxy's heart.
Speaker 3: It absolutely is Okay.
Speaker 2: So we know the meal. It's this clumpy river of
Speaker 2: glowing hydrogen and helium, and we know exactly who's eating it. Sagittarius,
Speaker 2: a quietly munching on an earth sized gaseous snack every
Speaker 2: decade just to keep the lights on, right, But who
Speaker 2: is cooking the meal? Where did this massive, perfectly timed
Speaker 2: river of gas actually come from the first place? That
Speaker 2: is the ultimate question, because as we've established, gas in
Speaker 2: the galactic center gets shredded. You don't just get a continuous,
Speaker 2: highly structured river of hot gas materializing out of nowhere.
Speaker 3: No, you go.
Speaker 2: Something massive, something with incredible energy, had to generate it
Speaker 2: and push it out onto this specific plunging orbit.
Speaker 3: And this is where the sheer detective work of modern
Speaker 3: astronomy comes into play. Astronomers couldn't just guess. They had
Speaker 3: to formulate hypotheses and examine a lineup of initial suspects.
Speaker 2: Let's hear the lineup.
Speaker 3: In an environment is densely packed and violently entered jetic
Speaker 3: as the galactic center, there are a few usual culprits
Speaker 3: responsible for generating loose, fast moving gas. The first suspect
Speaker 3: on the list was stellar winds from massive.
Speaker 2: Stars massive stars blowing wind.
Speaker 3: Massive stars, particularly O type stars or wolf rayed stars,
Speaker 3: are incredibly hot, volatile, and luminous. Because they've burn so hot,
Speaker 3: the radiation pressure pushing outward from their cores frequently overcomes
Speaker 3: their own.
Speaker 2: Gravity, so they just sort of fall apart outward.
Speaker 3: Basically, they constantly blow off their outer layers into space
Speaker 3: at thousands of kilometers per second right, So.
Speaker 2: You have these giant stars just constantly sweating off massive
Speaker 2: amounts of gas in all directions, flooding the area. That's
Speaker 2: suspect number one.
Speaker 3: The second major suspect was an explosive event, specifically something
Speaker 3: like a nova an explosion. A nova occurs in a
Speaker 3: binary system where a white dwarf star slowly siphons matter
Speaker 3: off a companion star. When enough hydrogen accumulates on the
Speaker 3: incredibly dense surface of the white dwarf, the pressure and
Speaker 3: temperature reach a critical point and boom, and it triggers
Speaker 3: a runaway thermonuclear explosion. This explosion doesn't destroy the star,
Speaker 3: but it blasts a distinct spherical shell of gas violently
Speaker 3: outward into the surrounding space.
Speaker 2: So suspect number two is basically a colossal, recurring nuclear
Speaker 2: bomb throwing off shrapnel in the form of gas.
Speaker 3: That's one way to put it. Yes, And the third
Speaker 3: suspect was tidal stripping. What's that This would be a
Speaker 3: much more localized scenario where a perfectly normal, stable star
Speaker 3: just happened to wander slightly too close to sgr A.
Speaker 2: On its orbit, wrong place, wrong time, exactly.
Speaker 3: The black holes immense gravity wouldn't swallow the star hold immediately,
Speaker 3: but it would literally rip the outer gaseous envelopes right
Speaker 3: off the star's surface.
Speaker 2: So it basically mugs the star for its gas.
Speaker 3: Yes, creating a trailing stream of material that would follow
Speaker 3: the star's path.
Speaker 2: Okay, so you have three very different, very plausible suspects.
Speaker 2: A massive star just blowing aggressively in the wind, a
Speaker 2: star exploding in a thermonuclear blast, or an unlucky star
Speaker 2: getting mugged for its outer layers by the supermassive black hole.
Speaker 3: Correct.
Speaker 2: If you are an astronomer, how do you even begin
Speaker 2: to figure out which one is the actual culprit? I mean,
Speaker 2: we talked earlier about the twenty six thousand light years
Speaker 2: of thick galactic dust sitting between Earth and the galactic center.
Speaker 3: It's a huge problem.
Speaker 2: If I look towards Sagittarius with a normal telescope, I
Speaker 2: just see a dark patch of nothing because the dust
Speaker 2: blocks all the visible light. How do you isolate the
Speaker 2: clues when you can't even see the crime scene with
Speaker 2: standard optics.
Speaker 3: The dust is the ultimate barrier. Visible light, the kind
Speaker 3: our eyes see gets scattered and absorbed by the interstellar dust.
Speaker 3: Particles long before it reaches Earth, so.
Speaker 2: You have to use a different kind of light.
Speaker 3: Exactly to pierce that twenty six thousand light year veil
Speaker 3: of dust. Astronomers cannot rely on visible light. They must
Speaker 3: observe in the infrared.
Speaker 2: Spectrum because infrared has longer wavelength.
Speaker 3: Yes, infrared light has longer wavelengths than visible light, allowing
Speaker 3: it to literally slip past the microscopic dust grains and
Speaker 3: travel all the way across the galaxy to our telescopes.
Speaker 3: That is so convenient, But simply using an infrared camera
Speaker 3: isn't enough. When you are trying to track something as
Speaker 3: small as an Earth mass cloud of gas. You need
Speaker 3: highly specialized instruments that can not only see the infrared light,
Speaker 3: but measure the exact minute movements of the gas emitting
Speaker 3: it right tracking it. The international team that finally cracked
Speaker 3: this case relied on two specific, incredibly sophisticated instruments called
Speaker 3: Sinfoni and Eris, mounted on the very large telescope in Chile.
Speaker 2: But wait, infrared alone doesn't give you a perfectly sharp image,
Speaker 2: right because even if the light makes it through the
Speaker 2: galactic dust, it still has to get through our own
Speaker 2: planet's atmosphere before it hits the telescope, Marrinshielder and our
Speaker 2: atmosphere is a total mess.
Speaker 3: That is the secondary and arguably more difficult challenge. Even
Speaker 3: if you collect pristine infrared light from the center of
Speaker 3: the galaxy, the moment it enters the Earth's atmosphere gets distorted. Right,
Speaker 3: the atmosphere is constantly moving, churning with different temperatures and densities.
Speaker 3: That turbulent air apps like a funhouse mirror, bending the
Speaker 3: incoming light.
Speaker 2: Waves, which is why stars twinkle.
Speaker 3: That is the exact reason why stars appear to twinkle
Speaker 3: to the naked eye. But in deep space astronomy, that
Speaker 3: twinkling violently blurs the image, turning a precise point of
Speaker 3: light into a smeared, unusable blob.
Speaker 2: So how do Symphony and Eris fix that?
Speaker 3: To solve this, they are equipped with one of the
Speaker 3: most important technological leaps in modern astronomy, adaptive optics.
Speaker 2: Adaptive optics I've read about this and it honestly sounds
Speaker 2: like science fiction.
Speaker 3: It really does.
Speaker 2: Instead of just building a bigger static mirror, they build
Speaker 2: a mirror that constantly changes its own shape to fight
Speaker 2: the atmosphere.
Speaker 3: It is a phenomenal feat of engineering. A system utilizing
Speaker 3: adaptive optics often shoots a powerful, precisely calibrated laser beam
Speaker 3: straight up into the night.
Speaker 2: Sky well laser beam like a Sci Fi Yes.
Speaker 3: That laser hits the sodium layer high in the upper
Speaker 3: atmosphere and causes it to glow, creating an artificial guide
Speaker 3: star right next to the object the telescope is trying
Speaker 3: to observe.
Speaker 2: Wow.
Speaker 3: Okay, Because the telescope system knows exactly what that artificial
Speaker 3: laser star should look like, a computer analyzes how the
Speaker 3: atmosphere is currently blurring and distorting.
Speaker 2: It, so it measures the distortion in real time.
Speaker 3: The computer runs these calculations hundreds of times a second
Speaker 3: and then sends signals to a secondary paper thin, deformable
Speaker 3: mirror inside the telescope, and.
Speaker 2: It actually bends the mirror.
Speaker 3: Yes, tiny actuators behind that mirror physically push and pull
Speaker 3: its surface, warping it in real time to perfectly cancel
Speaker 3: out the atmospheric distortion.
Speaker 2: That is unbelievable.
Speaker 3: It essentially removes the Earth's atmosphere from the equation entirely,
Speaker 3: giving ground based telescopes a level of sharpness and resolution
Speaker 3: that rivals or sometimes even exceeds space telescopes like Hubble.
Speaker 2: Okay, so just to recap the sheer amount of technology
Speaker 2: involved here, they are using infrared sensors to slice through
Speaker 2: twenty six thousand light years of thick galactic dust, right,
Speaker 2: and then they are shooting lasers into the sky to
Speaker 2: physically warp a mirror hundreds of times a second to
Speaker 2: cancel out the Earth's atmosphere.
Speaker 3: It's quite the setup.
Speaker 2: They finally have a crystal clear, magically sharp view of
Speaker 2: the galactic center. But what are Sinphoni and Eris actually
Speaker 2: doing with that clear view Because they aren't just taking
Speaker 2: a nice polaroid picture of the gas clouds. No, they
Speaker 2: are spectrographs. They are breaking the light down.
Speaker 3: Spectroscopy is arguably the most powerful tool in astronomer has.
Speaker 3: It is the science of capturing light and breaking it
Speaker 3: down into its component colors or specific wavelengths.
Speaker 2: Like a prism breaks white light into a.
Speaker 3: Rainbow, exactly like that. The reason this is so vital
Speaker 3: is that different chemical elements, when they are heated and energized,
Speaker 3: don't just glow a generic color. They emit light at
Speaker 3: very specific, mathematically precise signature. Wavelengths like a barcode. It
Speaker 3: is exactly like a chemical fingerprint. If you can see
Speaker 3: the fingerprint, you know exactly what element is present. For
Speaker 3: this particular investigation, the team programmed Symphony and eris to
Speaker 3: focus specifically on something called the hydrogen bracket gamma emission line.
Speaker 2: Okay, let's slow down and really explain that, because hydrogen
Speaker 2: bracket gamma emission line sounds incredibly intimidating.
Speaker 3: It's a mouthful.
Speaker 2: We establish that the g clouds are mostly made of hydrogen.
Speaker 2: What is the specific line and why is it the
Speaker 2: key to tracking them?
Speaker 3: To understand the bracket gamma line, we have to zoom
Speaker 3: all the way down to the quantum level of a
Speaker 3: single hydrogen atom.
Speaker 2: Okay, shrinking down.
Speaker 3: A hydrogen atom consists of one proton in the center
Speaker 3: and one electron orbiting it. Now that electron can't just
Speaker 3: orbit wherever it wants. It is restricted to very specific
Speaker 3: fixed energy levels or.
Speaker 2: Shells like rungs on a ladder.
Speaker 3: Good analogy. When the hydrogen atom is sitting in a calm,
Speaker 3: cold environment, the electron stays in its lowest energy level,
Speaker 3: the ground state. But the environment in your SAGITTARIUSA is
Speaker 3: anything but calm.
Speaker 2: Right. It's a cosmic mosh pit.
Speaker 3: It is flooded with intense, high energy ultraviolet radiation from
Speaker 3: surrounding stars. When that radiation hits a hydrogen atom in
Speaker 3: the g cloud, it transfers energy to the electron, bumping
Speaker 3: it up to a much higher energy level. Let's say
Speaker 3: it bumps it all the way up to the seventh
Speaker 3: energy level.
Speaker 2: But electrons are inherently lazy, right. They don't like being
Speaker 2: highly energized. They want to drop back down to where
Speaker 2: they started exactly.
Speaker 3: The excited state is unstable. Almost immediately, that electron will
Speaker 3: drop back down to a lower energy level. But energy
Speaker 3: cannot be destroyed. It has to go somewhere, so it
Speaker 3: spits it out. So as the electron drops, the atom
Speaker 3: releases that exact packet of excess energy in the form
Speaker 3: of a photon, a single particle of light. And here
Speaker 3: is the crucial mechanism. When an electron in a hydrogen
Speaker 3: atom drops specifically from the seventh energy level down to
Speaker 3: the fourth.
Speaker 2: Energy level Okay, seven to four, the.
Speaker 3: Photon it releases has an exact unchanging wavelength of two
Speaker 3: point one sixty six microns. That specific wavelength of infrared
Speaker 3: light is what we call the brack Gamba line.
Speaker 2: So by tuning these massive adaptive optics enabled telescopes in
Speaker 2: Chile to ignore all the chaotic blinding light of the
Speaker 2: millions of stars in the galactic center right, filtering all
Speaker 2: that out and looking only for that one hyper specific
Speaker 2: two point one sixty six micron shade of infrared light.
Speaker 2: They can essentially put on night vision goggles that only
Speaker 2: highlight hot energized hydrogen gas.
Speaker 3: That's exactly what they're doing.
Speaker 2: They can see exactly where the g clouds are against
Speaker 2: the darkness.
Speaker 3: They can see exactly where it is. But more importantly,
Speaker 3: spectroscopy allows them to see exactly how fast it is
Speaker 3: moving toward or away from us.
Speaker 2: Oh, because of the movement of the light.
Speaker 3: This is the crucial leap that turns a static picture
Speaker 3: into a three dimensional moving map. It relies on the
Speaker 3: Doppler effect.
Speaker 2: Ah, like the ambulance siren.
Speaker 3: Yes, the same physical phenomenon that makes an ambulance siren
Speaker 3: pitch higher as it drives toward you and pitch lower
Speaker 3: as it drives away applies to light waves.
Speaker 2: Okay, so how does that work with the gas clouds?
Speaker 3: If a clump of hydrogen gas in this is moving
Speaker 3: physically closer to Earth as it orbits the black hole,
Speaker 3: the light waves it emits get slightly compressed.
Speaker 2: So they squish together.
Speaker 3: Yes, that two point one sixty six micron bracket gamma
Speaker 3: line gets squished to a slightly shorter wavelength, shifting it
Speaker 3: toward the blue end of the spectrum a blue shift. Conversely,
Speaker 3: if the gas is moving away from us, the light
Speaker 3: wave stretches, shifting to a slightly longer wavelength toward the
Speaker 3: red end of the spectrum, a red shift.
Speaker 2: So by carefully measuring those minute microscopic shifts in the
Speaker 2: wavelength what astronomers call radial velocity right exactly, and combining
Speaker 2: that with the exact physical position of the gas on
Speaker 2: the sky over several years of observation, they aren't just
Speaker 2: taking a picture. They are mathematically reconstructing the exact three
Speaker 2: dimensional speed and trajectory of every single glowing clump in
Speaker 2: that river.
Speaker 3: It is incredibly precise work.
Speaker 2: It's like hitting rewind on a cosmic videotape. They didn't
Speaker 2: just see a cloud of gas. They mapped exactly where
Speaker 2: it was going, and, most important for our mystery, exactly
Speaker 2: where it came from.
Speaker 3: And when they finally took all that data and plotted
Speaker 3: the complete three D orbits of G one, G two
Speaker 3: and the newly discovered third clump over time, the math
Speaker 3: revealed something profound.
Speaker 2: What did the maths show them?
Speaker 3: When they overlaid the calculated orbits of all three clumps?
Speaker 3: They found that they all travel on paths with almost
Speaker 3: identical orientations, eccentricities, and inclinations. Wow. This raises an important question.
Speaker 3: What are the actual odds of that happening completely by chance?
Speaker 2: Probably pretty low.
Speaker 3: You have to consider the environment. The galactic center is
Speaker 3: a chaotic, turbulent mess, swarming with millions of stars, competing
Speaker 3: gravitational pulls, random gas clouds, and intense radiation pressure.
Speaker 2: Right, things are just bouncing everywhere.
Speaker 3: The mathematical probability of three distinct, entirely unrelated gas clouds
Speaker 3: randomly falling into the exact same, highly specific, deeply plunging
Speaker 3: elong orbit around the black hole is vanishingly small. It
Speaker 3: borders on statistical impossibility.
Speaker 2: It's like finding three different people from three entirely different
Speaker 2: countries who somehow ended up walking the exact same convoluted
Speaker 2: path through times square on New Year's eve down to
Speaker 2: the exact footstep completely by coincidence.
Speaker 3: Yes, a very good analogy, It just doesn't.
Speaker 2: Happen in a chaotic system.
Speaker 3: The data proved beyond a reasonable shadow of a doubt
Speaker 3: that these were not unrelated phenomena. The shared orbital parameters
Speaker 3: were the definitive smoking gun.
Speaker 2: So they are connected.
Speaker 3: They must share a single localized point of origin. Finding
Speaker 3: the shared orbit is what transformed these isolated sightings of
Speaker 3: G one and G two from mere curiosities into a connected,
Speaker 3: trackable timeline of events.
Speaker 2: So the detectives have their clues. They have the chemical footprint,
Speaker 2: the hot ionized hydrogen glowing at two point one sixty
Speaker 2: six microns. They have the orbital footprint, this incredibly specific
Speaker 2: plunging path that bypasses a normal accretion disc and goes
Speaker 2: straight toward the black hole, and they have the speed.
Speaker 2: So they take all this incredibly precise, massive amount of
Speaker 2: data gathered by Sinfona and the Ears, they plug it
Speaker 2: into their computers and they hit the cosmic rewind button.
Speaker 3: Racing the entire G one two three streamer backward through
Speaker 3: space and time.
Speaker 2: Following the river up to its source, and the trail
Speaker 2: lands squarely on one specific suspect from our lineup. They
Speaker 2: finally unmasked the culprit.
Speaker 3: Yes, the culmination of all this tracking was incredibly precise
Speaker 3: by mathematically following the trajectory of the streamer backward, both
Speaker 3: in its physical spatial position and its radial velocity.
Speaker 2: Where did it lead?
Speaker 3: The path points directly back to a very specific massive
Speaker 3: star system. This system is located in what astronomer is
Speaker 3: called the clockwise disc, a distinct rotating disc of massive
Speaker 3: young stars that orbit SGRA at a distance of about
Speaker 3: a tenth of a parsec.
Speaker 2: A tenth of a parsec, so pretty close.
Speaker 3: Very close in galactic terms, and the specific star system
Speaker 3: the streamer points to is called Iris sixteen.
Speaker 2: Sw IRS sixteen sw I've always thought it sounds like
Speaker 2: a tax form or maybe an obscure radio station.
Speaker 3: It does lack a certain poetry, it really does.
Speaker 2: But it's actually something so much cooler and so much
Speaker 2: more violently energetic than just a single normal star. It's
Speaker 2: a contact binary star.
Speaker 3: A very extreme type of system.
Speaker 2: Let's really break that concept down, because this specific type
Speaker 2: of star system is the physical engine driving the whole operation.
Speaker 2: What exactly makes a contact binary so different from the
Speaker 2: stars we are used to.
Speaker 3: To understand the extreme nature of IRS sixteen SW, we
Speaker 3: have to look at how stars live. Most stars, like
Speaker 3: our own son, are solitary objects, comfortably dominating their local
Speaker 3: solar system.
Speaker 2: Right just hanging out alone.
Speaker 3: But a huge percentage of stars in the universe are
Speaker 3: actually born in pairs orbiting a common center of gravity.
Speaker 3: These are binary systems.
Speaker 2: Okay, two stars orbiting each other.
Speaker 3: Now. In a typical binary system, there is a comfortable
Speaker 3: vast distance between the two stars. They orbit each other
Speaker 3: calmly over years or central. But IRS sixteen s W
Speaker 3: is an extreme, highly evolved case.
Speaker 2: They are not keeping their distance, not at all.
Speaker 3: It consists of two incredibly massive, fiercely hot stars that
Speaker 3: are orbiting each other so closely that their outer atmospheres
Speaker 3: their stellar envelopes are practically.
Speaker 2: Touching like their atmospheres are touching.
Speaker 3: Yes, they are locked in this incredibly tight, incredibly fast,
Speaker 3: and incredibly violent gravitational embrace. The orbital period is so
Speaker 3: short and the proximity so close that the stars are
Speaker 3: physically distorting each other's shapes into tear drops due to
Speaker 3: the mutual gravitational pull.
Speaker 2: Tear drop shaped stars that is so bizarre to think about,
Speaker 2: and because they are massive stars, they aren't just sitting
Speaker 2: there quietly, calmly glowing right.
Speaker 3: Definitely not.
Speaker 2: We mentioned earlier in our suspect lineup that massive stars
Speaker 2: have intense stellar winds. A star like our Sun has
Speaker 2: a solar wind, It pushes out a steady stream of particles,
Speaker 2: which causes the auroras here on Earth.
Speaker 3: A relatively gentle breeze.
Speaker 2: But the stellar winds coming off massive stars like those
Speaker 2: in IRS sixteen s W are on a completely different magnitude.
Speaker 2: They are constantly blowing a literal hurricane of hot plasma
Speaker 2: and gas off their surfaces at millions of miles an hour.
Speaker 3: Millions.
Speaker 2: So if you have two of these giant, volatile stars
Speaker 2: practically rubbing against each other, both pushing out these colossal.
Speaker 3: Winds, the resulting fluid dynamics are explosively complex. The researchers
Speaker 3: didn't just assume this would create gas clouds. They ran
Speaker 3: highly sophisticated three D hydrodynamical computer simulations to model exactly
Speaker 3: what would happen to the gas in this very specific scenario.
Speaker 2: And what happens when two stellar hurricanes hit each other.
Speaker 3: When you have two massive stars in a contact binary,
Speaker 3: both actively projecting intense stellar winds outward at thousands of
Speaker 3: kilometers per second. Those winds don't just pass through each other,
Speaker 3: they crash, They violently collide in the extremely narrow space
Speaker 3: between the two stars.
Speaker 2: Okay, I have an analogy for this, to try and
Speaker 2: bring these massive astrophysical fluid dynamics down to Earth.
Speaker 3: I love your analogies. Go for it.
Speaker 2: Imagine you take two industrial strength gas powered leaf blowers.
Speaker 2: You strap them to a table point, the nozzles directly
Speaker 2: at each other, with maybe an inch of space between them,
Speaker 2: and turn them both onto maximum power.
Speaker 3: That sounds dangerous, very dangerous.
Speaker 2: The air rushing out of both nozzles is incredibly fast,
Speaker 2: but right in the middle and that one inch gap
Speaker 2: where those two high speed air streams crash head on
Speaker 2: into each other, the air suddenly has nowhere to go.
Speaker 3: It's trapped.
Speaker 2: It can't move forward, and it can't go backward. It
Speaker 2: violently crashes, It compresses, and it forms this incredibly dense, turbulent,
Speaker 2: high pressure nod of air right in the center. And
Speaker 2: eventually the pressure in that central knot gets so overwhelmingly
Speaker 2: high that chunks of that compressed air just have to
Speaker 2: escape the trap. They get violently pushed out the sides,
Speaker 2: blowing away as dense cohesive bursts.
Speaker 3: That is an exceptionally accurate visualization of the shock physics
Speaker 3: at play.
Speaker 2: Really, the leaf blowers work absolutely.
Speaker 3: When those stellar winds collide in the space between the
Speaker 3: stars of IRS sixteen s W, the kinetic energy of
Speaker 3: the collision has to go somewhere. It creates a massive
Speaker 3: standing shockwave. Wow. The high pressure not created by this
Speaker 3: collision compresses the gas to a tremendous degree. And here
Speaker 3: is where it elegantly ties back to the optical physics
Speaker 3: we discussed earlier regarding the glowing clumps.
Speaker 2: The squared brightness thing.
Speaker 3: Exactly, that violent collision compresses the local gas so much
Speaker 3: that it crosses the crucial density threshold required to dramatically
Speaker 3: increase its emission brightness. It becomes dense enough and hot
Speaker 3: enough to glow brilliantly in the infrared spectrum.
Speaker 2: So the leaf blowers, the colliding stellar winds are actually
Speaker 2: manufacturing the glowing clumps in the river. The binary star
Speaker 2: is literally a clump factory.
Speaker 3: Precisely, the shockwave heavily compresses the gas as this compressed
Speaker 3: material builds up in the collision zone, it becomes hydrodynamically unstable.
Speaker 2: Gets pushed out.
Speaker 3: Besides, eventually that dense pocketive gas detaches from the binary
Speaker 3: star system entirely as an individual, highly cohesive clump rather
Speaker 3: than just a diffew spray of.
Speaker 2: Atoms, and that's free.
Speaker 3: Once that dense clump is pushed outward and escapes the
Speaker 3: immediate localized gravitational grip of the two orbiting stars, it
Speaker 3: enters the wider environment of the galactic.
Speaker 2: Center, where the big boss tucks over.
Speaker 3: Immediately, it gets caught in the overwhelming overarching gravitational pull
Speaker 3: of Sagittarius A. It gets yanked into that highly eccentric,
Speaker 3: plunging orbit we tracked earlier, beginning its long inward journey
Speaker 3: and officially joining the continuous flow of the G one
Speaker 3: two three streamer.
Speaker 2: That is incredible. But wait, if I put on my
Speaker 2: skeptical hat for a second and look at the data.
Speaker 2: Go ahead, If all these clumps G one, G two,
Speaker 2: and the third clump are all being manufactured by and
Speaker 2: ejected from the exact same binary star system IRS sixteen
Speaker 2: s W, why aren't they on the exact same orbit.
Speaker 3: That's a very fair question.
Speaker 2: You mentioned earlier that their orbits have almost identical orientations,
Speaker 2: and that was enough to prove a connection, But there
Speaker 2: are small measurable differences in their paths. G one's orbit
Speaker 2: isn't perfectly flushed with G two's.
Speaker 3: No, it's not.
Speaker 2: Doesn't that discrepancy throw a wrench in the entire theory?
Speaker 2: If they come from the exact same gun, shouldn't they
Speaker 2: follow the exact same bullet trajectory.
Speaker 3: On a static stationary system, Yes, they would, But pointing
Speaker 3: out those slight orbital differences actually strengthens the theory beautifully
Speaker 3: because it proves the dynamic nature of the source. How So,
Speaker 3: think about the physical reality of IRS sixteen s W.
Speaker 3: It is a binary system, meaning those two massive stars
Speaker 3: are constantly rapidly revolving around each other. But beyond that,
Speaker 3: the entire binary system itself, the whole package is actively
Speaker 3: orbiting around the supermassive black hole as part of that
Speaker 3: clockwise disc of stars.
Speaker 2: Eh. It's moving.
Speaker 3: It is a moving, rotating, spinning platform in space. So
Speaker 3: when the colliding stellar winds build up enough pressure and
Speaker 3: eject a clump of gas, say the clump that became
Speaker 3: G one, the binary star is located in one highly
Speaker 3: specific position in its orbit around the black hole, facing
Speaker 3: one specific direction and moving into specific velocity.
Speaker 2: Ah, I get it. It's like throwing a baseball out
Speaker 2: the window of a moving car. The speed and direction
Speaker 2: of the car entirely affect the final trajectory of the
Speaker 2: ball exactly.
Speaker 3: The initial vector of the gas clump is a combination
Speaker 3: of the ejection force and the underlying movement of the
Speaker 3: star system itself. Now fast forward ten or twenty years
Speaker 3: to when the collision zone builds up enough pressure to
Speaker 3: eject the next major clump.
Speaker 2: G two, the car has driven further down the road.
Speaker 3: Exactly, in that intervening time, the binary star system IRS
Speaker 3: sixteen SW has physically moved further along its own massive
Speaker 3: orbit around the black hole. It is in a different
Speaker 3: spatial location.
Speaker 2: So the angles change.
Speaker 3: The angles of ejection of change slightly relative to the
Speaker 3: black hole. The rotational phase of the binary stars themselves
Speaker 3: might be slightly different at the exact moment of ejection.
Speaker 2: That makes perfect sense.
Speaker 3: Therefore, the resulting orbital path of G two will be
Speaker 3: profoundly similar to G one because it originated from the
Speaker 3: same core gravitational zone. But it will inevitably have minute,
Speaker 3: mathematically predictable differences.
Speaker 2: Caused by the simple fact that the clump factory itself
Speaker 2: is spinning and moving through space over time.
Speaker 3: Precisely, when astrophysicists modeled the ejection of material from a
Speaker 3: moving orbit matching IRS sixteen SW, the slight documented differences
Speaker 3: in the orbits of G one, G two and the
Speaker 3: third clump perfectly matched the modeled ordinal dynamics of a
Speaker 3: moving source.
Speaker 2: That is just It's incredibly satisfying when the physics puzzle
Speaker 2: pieces fit together that perfectly.
Speaker 3: That's what every scientist lives for.
Speaker 2: You have the fluid dynamics of the colliding winds perfectly
Speaker 2: explaining why the gas is hot, compress and clumpy enough
Speaker 2: to glow brightly in the infrared. You have the macro
Speaker 2: movement of the binary star system perfectly explaining this slight
Speaker 2: measurable variations in the orbital paths of the distinct clumps
Speaker 2: over decades. And you have the overall overarching graph vitational
Speaker 2: trajectory pointing right down the barrel, delivering this material straight
Speaker 2: to SAGITTARIUSA. It leaves absolutely no room for doubt.
Speaker 3: It truly is a triumph of modern astronomy. It demonstrates
Speaker 3: how observational data gathering, photons that have traveled for twenty
Speaker 3: six thousand years, and theoretical hydrodynamical modeling can work perfectly
Speaker 3: in tandem to solve a complex, multi variable mystery in
Speaker 3: an environment we can never physically visit.
Speaker 2: So, after taking this hour to really dig into the
Speaker 2: mechanics of this, what does this all mean for our
Speaker 2: understanding of the universe.
Speaker 3: It's a huge paradigm shift.
Speaker 2: When we step back from the specific infrared data points
Speaker 2: and the orbital math and look at this whole story.
Speaker 2: We've clearly moved past just solving a niche mystery about
Speaker 2: some glowing gas clouds puzzling a few astronomers.
Speaker 3: We have uncovered an entire ecosystem.
Speaker 2: A majestic and frankly terrifying ecosystem operating continuously at the
Speaker 2: center of our galaxy. It fundamentally changes the narrative. It's
Speaker 2: not just a story about a dark, dormant black hole
Speaker 2: are libitrarily passibly eating whatever unlucky material happens to wander
Speaker 2: too close.
Speaker 3: Are from it.
Speaker 2: It is a highly structured, perfectly balanced, mechanically driven cycle.
Speaker 2: You have this chaotic, dense disk of material swirling around
Speaker 2: the black hole where massive volatile stars are born, yes
Speaker 2: the clockwise disc. These stars live incredibly fierce short lives
Speaker 2: and frequently pair up as these extreme violent contact binaries
Speaker 2: like IRS sixteen s w their violent lives and constantly
Speaker 2: colliding winds act as a mechanical factory.
Speaker 3: Churning out these dense compressed clouds of hot plasma.
Speaker 2: And those clouds inevitably get pulled inward by the massive
Speaker 2: gravity gradient, stretching out and forming this glowing, structured river
Speaker 2: that bypasses the slow accretion disc and delivers a slow, steady,
Speaker 2: highly efficient drip of fuel directly to the supermassive black hole.
Speaker 3: The black hole that anchors and dictates the gravity of
Speaker 3: the entire system.
Speaker 2: It's not a random feeding it is a continuous, self sustaining,
Speaker 2: deeply connected loop.
Speaker 3: And if we connect this localized discovery to the much
Speaker 3: broader overarching picture of astrophysics and cosmology, the implications are profound. Also,
Speaker 3: for decades, the scientific community has tended to study different
Speaker 3: fields of astronomy in somewhat isolated silos out of sheer
Speaker 3: necessity due to their complexity.
Speaker 2: Because there's just too much to know.
Speaker 3: Right, We have the field of stellar evolution, which focuses
Speaker 3: entirely on how individual stars are born from nebulas, how
Speaker 3: they live, how they burn their fuel, and how they
Speaker 3: eventually died.
Speaker 2: Okay, that's a one silo.
Speaker 3: We have the field of interscullar gas dynamics, which relies
Speaker 3: on heavy fluid mathematics to model how plasmas and atomic
Speaker 3: clouds move shock and cool through the vacuum.
Speaker 2: Of space Silo number two.
Speaker 3: And then we have the entirely separate study of active
Speaker 3: galactic nuclei and black hole feeding mechanisms, which tries to
Speaker 3: understand how the dark, incredibly massive cores of galaxies grow,
Speaker 3: emit radiation, and evolve over billions of years.
Speaker 2: And what you were saying is that this single discovery
Speaker 2: in our own galac center just grabs all three of
Speaker 2: those massive, historically separate fields of study and ties them
Speaker 2: tightly into a single, undeniable.
Speaker 3: Knot precisely, it elegantly visibly proves that these cosmic processes
Speaker 3: are not isolated phenomena happening independently of one another. Stellar revolution,
Speaker 3: gas dynamics, and black hole feeding are intimately mechanically and
Speaker 3: crucially linked.
Speaker 2: They're all part of the same machine.
Speaker 3: The life cycle of the stars residing in the galactic
Speaker 3: center directly dictates the feeding habits, the energy output, and
Speaker 3: ultimately the growth rate of the supermassive black hole.
Speaker 2: Wow.
Speaker 3: The violent death and volatility of matter happening on the
Speaker 3: relatively small stellar scale acts as the direct fuel source
Speaker 3: for the gravitational giant operating on the massive galactic scale.
Speaker 2: It scales all the way up.
Speaker 3: By observing the G one two three streamer and its
Speaker 3: source IRS sixteen s W, we are seeing right here
Speaker 3: in our own milky Way, a highly localized, perfectly observable
Speaker 3: version of the exact physical processes that likely shape the evolution, growth,
Speaker 3: and radiation output of entire galaxies across the entire observable universe.
Speaker 3: That is just staggering. It proves that even in an
Speaker 3: environment as violently chaotic, dense, and seemingly random as the
Speaker 3: center of a galaxy, there is an underlying, beautiful mechanical
Speaker 3: order to how mass is transferred, compressed, and ultimately consumed.
Speaker 2: It really is breathtaking when you take a moment to
Speaker 2: internalize the sheer scale and the mechanical perfection of it all.
Speaker 3: It is a beautiful machine.
Speaker 2: To briefly recap this incredible journey for you listening. It
Speaker 2: all started with a mysterious, faint, glowing clump G two
Speaker 2: spotted through the interstellar dust braving the seemingly insurmountable spaghetification
Speaker 2: forces of a super massive black hole back.
Speaker 3: In twenty twelve, and that single anomaly sparked everything.
Speaker 2: That initial anomaly led to a decade of data mining
Speaker 2: and the profound realization that G two, along with the
Speaker 2: earlier clump G one, and a newly formed third clump,
Speaker 2: weren't isolated random clouds at all.
Speaker 3: But highly compressed illuminated rapids in a continuous flowing cosmic
Speaker 3: river of hot plasma.
Speaker 2: Diving straight towards SAGITTARIUSA. By pushing technology to its absolute limit,
Speaker 2: utilizing mind bending adaptive optics to cancel out our own
Speaker 2: atmosphere and highly sensitive spectrographs to track the exact Doppler
Speaker 2: shifted infrared signature of hot hydrogen.
Speaker 3: The stronomers were able to trace that fast moving river
Speaker 3: backward through twenty six thousand light years of incredibly hostile.
Speaker 2: Space, and they found the definitive source, a pair of
Speaker 2: massive stars locked in a violent, high speed orbital embrace,
Speaker 2: violently crashing their stellar winds together like cosmic leaf blowers.
Speaker 3: Creating dense, glowing knots of gas that break off and
Speaker 3: feed our sleeping giant of a black hole one precise
Speaker 3: Earth sized meal every ten years.
Speaker 2: It is a remarkable testament to human curiosity, the scientific
Speaker 2: method and breath taking technological advancement that we, sitting on
Speaker 2: a small, rocky planet on the edge of the galaxy
Speaker 2: can piece together such a complex, invisible narrative taking place
Speaker 2: in the most extreme, dream highly obscured environment imaginable.
Speaker 3: It really is one of the greatest detective stories ever told.
Speaker 2: It absolutely is. But as with any good story, wrapping
Speaker 2: up this mystery just opens the door to another one.
Speaker 3: Always there's always another mystery.
Speaker 2: It leaves me with a final lingering question to ponder
Speaker 2: as we wrap up today. We establish that massive stars
Speaker 2: like the ones in IRS sixteen s W live incredibly volatile,
Speaker 2: furious lives.
Speaker 3: Yes, very short, very furious lives.
Speaker 2: Because they burn so hot and blow off so much mass,
Speaker 2: they burn through their nuclear fuel incredibly quickly compared to smaller,
Speaker 2: calmer stars like our Sun. They might only live for
Speaker 2: a few million years.
Speaker 3: A blink of an eye in cosmic terms.
Speaker 2: So, if this one specific contact binary star system is
Speaker 2: essentially operating as a slow drip I V solely responsible
Speaker 2: for keeping Sagittarius aphed and ticking right now, what happens
Speaker 2: to the center of our galaxy when that specific star
Speaker 2: system inevitably runs out of fuel and dies in a supernova?
Speaker 3: That is a million dollar question.
Speaker 2: Will that continuous river of gas dry up, Will our
Speaker 2: supermassive black hole finally go entirely hungry it's accretion dist
Speaker 2: emptying out falling completely utterly dormant and dark. Or is
Speaker 2: the dense, dusty heart of the Milky Way secretly filled
Speaker 2: with a whole hidden ecosystem of unseen, tightly wound leafblower
Speaker 2: binary stars just waiting in the wings to take its
Speaker 2: place and keep the cosmic engine running