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: Somewhere out there, right like deep in the dustiest, absolutely
Speaker 2: most violent center of our galaxy, there is this invisible
Speaker 2: cosmic metronome that's just been ticking away for over thirty years.
Speaker 3: Yeah, it's pretty wild to think about.
Speaker 2: Right, Just imagine the sheer scale of that for a second.
Speaker 2: Every twenty minute, just boom, a massive blast of radio
Speaker 2: energy washes over the Earth. It's perfectly timed. It's incredibly powerful,
Speaker 2: and it is utterly invisible to the naked.
Speaker 3: Eye, completely invisible, and for.
Speaker 2: Decades, the absolute smartest astrophisms in the world had well,
Speaker 2: they had absolutely no idea what was setting off this timer.
Speaker 3: None at all. It really is one of the most
Speaker 3: I guess, eerie pictures in modern astronomy. You have these
Speaker 3: phenomenal bursts of energy just rhythmically pulsing out of the
Speaker 3: absolute dark like clockwork exactly, and we're picking up the signal.
Speaker 3: You know, we know something enormous is out there generating it,
Speaker 3: but the actual mechanism behind it has just remained this
Speaker 3: complete void in our understanding.
Speaker 2: Well, our mission today is to finally unravel that exact mystery.
Speaker 2: We're going to explore what astronomers call long period transience
Speaker 2: or lpts, right, and we're going to look at this
Speaker 2: truly ground breaking new discovery. It's a specific star system
Speaker 2: designated a scott O J seventeen forty five.
Speaker 3: Yeah, quite a cashy name, right, Oh.
Speaker 2: They always have the best names in astronomy. But this
Speaker 2: single newly mapped system is finally giving the scientific community
Speaker 2: the answers they've been so desperately searching for.
Speaker 3: It's changing everything, honestly.
Speaker 2: Okay, let's unpack this because to understand why this new
Speaker 2: discovery is so revolutionary, we first have to look at
Speaker 2: how these signals behave in the wild, right, Like, why
Speaker 2: are they so incredibly difficult to track down in the
Speaker 2: first place.
Speaker 3: So when we talk about a transient in astronomy, we
Speaker 3: are generally talking about, well, anything the sky that changes
Speaker 3: over a short human time.
Speaker 2: Scarce s meaning what exactly like a.
Speaker 3: Star exploding, a comet passing by, maybe a solar flare,
Speaker 3: just something that happens relatively quickly, but a long period
Speaker 3: transient in this specific context refers to objects that produce
Speaker 3: these bright, repeating bursts of light, specifically at radio wavelengths.
Speaker 2: Okay, I got it.
Speaker 3: Now, the universe is, you know, it's a noisy, flashy place.
Speaker 3: They are actually quite used to things bursting in space.
Speaker 2: Right, Things blow up all the time exactly.
Speaker 3: But the timing of these specific lpts is what makes
Speaker 3: them such an absolute anomaly. Usually, when we find fast
Speaker 3: flashing objects, they repeat very rapidly, like how we're talking
Speaker 3: fractions of a second. These objects they operate on a
Speaker 3: completely different, almost languid timescale. They repeat on the order
Speaker 3: of minutes or sometimes even hours.
Speaker 2: Which I mean, if you think about the sheer amount
Speaker 2: of energy required to send a signal across the entire galaxy,
Speaker 2: a twenty minute gap feels like an eternity.
Speaker 3: Oh, it is an absolute eternity in high energy physics,
Speaker 3: and their behavior is wildly inconsistent. Too inconsistent how well,
Speaker 3: as you mentioned at the beginning, we have some of
Speaker 3: these lpts that have been pulsing with this perfect, unbroken
Speaker 3: rhythm for over three decades, just NonStop, relentless, a totally
Speaker 3: reliable beat. But then you have other transients in this
Speaker 3: exact same category that will pulse rhythmically for a while
Speaker 3: and then just well go completely dark for days at a.
Speaker 2: Time, just nothing, no signal at all.
Speaker 3: Nothing, and some go permanently radio silent. It's as if
Speaker 3: the engine just flooded and shut down foreverythingh that's frustrating.
Speaker 2: And to make matters even more complicated, almost all of
Speaker 2: these lpts have been discovered right in the middle of
Speaker 2: the Milky Way, right like close to the galactic center,
Speaker 2: which is essentially a massive cosmic smog bank.
Speaker 3: That is honestly the perfect way to describe it. It's
Speaker 3: a smog bank. The center of our galaxy is just
Speaker 3: packed with these dense clouds of gas, interstellar dust, carbon,
Speaker 3: silicate's ice.
Speaker 2: So it's just filthy out there, it really is.
Speaker 3: And this presents a massive observational hurdle for us. You
Speaker 3: can't just point a standard optical telescope like the kind
Speaker 3: that detects visible light at the galactic center and expect
Speaker 3: to see what's going on.
Speaker 2: Because the dust acts like a physical wall to the light.
Speaker 3: Right. Precisely, it comes down to how different wavelengths of
Speaker 3: light interact with physical matter. Visible light has a relatively
Speaker 3: short wavelength, right, so when it hits a microscopic particle
Speaker 3: of cosmic dust, the light wave just scatters, It bounces
Speaker 3: off in a completely different direction and never actually reaches
Speaker 3: our telescopes.
Speaker 2: Which is why the center of the galaxy just looks
Speaker 2: dark to the naked eye exactly.
Speaker 3: But radio waves, they have incredibly long wavelengths. We're talking
Speaker 3: meters or even kilometers long. They really, oh yeah, So
Speaker 3: instead of hitting those tiny dust particles and scattering, the
Speaker 3: radio waves just they just glide right over them. They
Speaker 3: pass completely through the galactic smog and eventually hit our
Speaker 3: radio dishes here on Earth.
Speaker 2: Okay, So I am imagining this like trying to observe
Speaker 2: a street scene while standing on the roof of a
Speaker 2: skyscraper in a heavily smoggy city.
Speaker 3: Okay, I like that, right.
Speaker 2: So you are looking down, but you cannot see a
Speaker 2: single car, a single pedestrian, or even the street itself
Speaker 2: because the smog is completely opaque.
Speaker 3: Right, it's just a wall of gray exactly.
Speaker 2: But every twenty minutes you hear this massive booming car
Speaker 2: horn cutting right through the air. You know for a
Speaker 2: fact something huge is down there making that noise, but
Speaker 2: you have zero visual conformation of its shape, its color,
Speaker 2: or like how many wheels it has.
Speaker 3: What a fantastic visualization. That is exactly the dilemma. You
Speaker 3: only have the sound of the horn, which is our
Speaker 3: radio burst. Because you can't see the actual source, and
Speaker 3: because these births happen so infrequently, they're remarkably hard to discover.
Speaker 3: I'd imagine most radio telescope surveys they scan the sky
Speaker 3: very quickly. They look at a patches sky, record what's
Speaker 3: there for maybe five minutes, and then move on to
Speaker 3: the next patch.
Speaker 2: Oh, I see the problem. If you are only looking
Speaker 2: for five minutes and the object only pulses every twenty.
Speaker 3: Minutes, you're going to miss it almost every single time.
Speaker 2: Wow. Which explains why we.
Speaker 3: Know of a few of them exactly. Despite the vastness
Speaker 3: of the galactic Center, astronomers have only managed a catalog
Speaker 3: about a dozen of these strained sources to date, just twelve.
Speaker 2: That is a tiny number for an entire galaxy.
Speaker 3: It really is. And what's fascinating here is the sheer
Speaker 3: diversity among just those twelve objects. I mean, even within
Speaker 3: such a tiny sample size. Their pulse profiles, their brightness,
Speaker 3: their periods of silence, they're all completely different.
Speaker 2: They don't match, not at all.
Speaker 3: They don't neatly fit into a single easily identifiable category.
Speaker 2: So if you are an astronomer and all you have
Speaker 2: is the booming horn and the smog, how do you
Speaker 2: even be begin to guess what's making the noise? I
Speaker 2: mean you have to look at the vehicles you already
Speaker 2: know about, right.
Speaker 3: You start with the usual suspects. Yeah, when you only
Speaker 3: have repeating radio pulses to go on, you have to
Speaker 3: ask the fundamental question, what else in the universe produces
Speaker 3: repeating radio bursts?
Speaker 2: Okay? And what does well?
Speaker 3: For decades, the absolute undisputed king of the repeating radio
Speaker 3: burst has been the pulsar. So the initial rating theory,
Speaker 3: the assumption that drove a lot of the early research,
Speaker 3: was that these lpts were simply pulsars that were just
Speaker 3: spinning very very slowly.
Speaker 2: Okay, let's look at the pulsar theory, because my understanding
Speaker 2: is that pulsars are some of the most extreme objects
Speaker 2: in existence. Like they aren't normal.
Speaker 3: Stars, oh far from it. A pulsar is a highly magnetized,
Speaker 3: rotating neutron.
Speaker 2: Star, and a neutron star is well.
Speaker 3: To understand what that means, we have to look at
Speaker 3: how a massive star dies. When a star much much
Speaker 3: larger than our Sun burns through all its nuclear fuel,
Speaker 3: it can no longer support its own weight against the
Speaker 3: crushing force of gravity, so it collapses violently. The core
Speaker 3: collapses inward in a fraction of a second, and the
Speaker 3: outer layers are just blown away in a massive supernova explosion.
Speaker 2: And what's left behind in the absolute center of that
Speaker 2: explosion is the neutron star.
Speaker 3: Yes, and it is dense. You take a mass roughly
Speaker 3: equivalent to our entire Sun, and you crush it down
Speaker 3: into a sphere about the size of a small city, like.
Speaker 2: The city like twenty kilometers across me exactly.
Speaker 3: The density is just incomprehensible to the human brain. A
Speaker 3: single teaspoon of neutron star material would weigh billions of tons.
Speaker 2: That's insane, and because of.
Speaker 3: The conservation of angular momentum, you know, much like an
Speaker 3: ice skater pulling their arms in to spin faster.
Speaker 2: Right, They pull their arms in and suddenly they're a blur.
Speaker 3: Yes, exactly, because this massive core collapse down so drastically,
Speaker 3: this tiny, ultra dense sphere is rotating at staggering.
Speaker 2: Speeds, and that rotation is what creates the lighthouse effect
Speaker 2: we see from Earth roax.
Speaker 3: Right, these neutron stars have intensely powerful magnetic flare fields.
Speaker 3: As they spin, they funnel charge particles to their magnetic poles,
Speaker 3: accelerating them to near the speed of light and blasting
Speaker 3: out twin beams of radio waves.
Speaker 2: So it's shooting out beams from the top and bottom essentially.
Speaker 3: Yeah, And if the star's magnetic axis is tilted relative
Speaker 3: to its actual rotation, those beams sweep through space like
Speaker 3: the beam of a lighthouse. Oh I fall, So every
Speaker 3: time that beam sweeps across the Earth, a radio telescope
Speaker 3: picks up a pulse that is your pulsar.
Speaker 2: Okay, but here is where I see the physical contradition
Speaker 2: with the theory. You mentioned that an ice skater pulls
Speaker 2: their arms in to spin faster, So a newly born
Speaker 2: pulsar should be spinning at a dizzying speed, right, like
Speaker 2: multiple times a second.
Speaker 1: Oh.
Speaker 3: Absolutely, A typical pulsar rotates anywhere from once every few
Speaker 3: seconds to hundreds of times a second. Yeah. The crab pulsar,
Speaker 3: for example, rotates about thirty times a second.
Speaker 2: But the signals we are picking up from these long
Speaker 2: period transients they repeat every twenty minutes. If the light
Speaker 2: pulse is directly tied to the spin of the star,
Speaker 2: that means the star is to twenty full minutes to
Speaker 2: complete a single rotation.
Speaker 3: Yes, and you have isolated the exact flaw in the
Speaker 3: assumption right there. The math simply does not.
Speaker 2: Support it because it's too slow.
Speaker 3: It's not just that twenty minutes is unusually slow, it's
Speaker 3: that a twenty minute rotation completely breaks the fundamental physics
Speaker 3: of how a pulsar operates.
Speaker 2: Wait, really, why does the speed of the spin dictate
Speaker 2: whether the light turns on or off. Shouldn't a slow
Speaker 2: lighthouse still sweep a beam.
Speaker 3: In a mechanical lighthouse on Earth? Yes, you just turned
Speaker 3: the motor down. But a pulsar is at mechanical It's
Speaker 3: an electromagnetic engine.
Speaker 2: Okay.
Speaker 3: The radio emission is entirely powered by the rotational kinetic
Speaker 3: energy of the star. Itself. As the neutron star spins,
Speaker 3: its massive magnetic field spins with it, and that generates
Speaker 3: a staggering electric field that literally rips charged particles right
Speaker 3: off the surface of the star.
Speaker 2: Whoa, it pulls its own surface off.
Speaker 3: Yeah, and then it flings them ount into space. Yeah.
Speaker 3: But this entire mechanism requires an incredibly fast spin to
Speaker 3: generate enough voltage to do that.
Speaker 2: Ah, So there is a threshold, like you have to
Speaker 2: be spinning at least x speed to power the beam exactly.
Speaker 3: We call it the death line.
Speaker 2: The death line sounds ominous.
Speaker 3: It is for the pulsar. As a pulsar ages over
Speaker 3: millions of years, it gradually loses energy and its rotation
Speaker 3: slows down. As it slows, the electric voltage drops. Once
Speaker 3: the rotation drops below that critical speed, usually around a
Speaker 3: few seconds per rotation, the voltage is no longer strong
Speaker 3: enough to pull particles off the.
Speaker 2: Surface, so the engine just cuts out.
Speaker 3: The acceleration stops, the radio beams completely shut off, the
Speaker 3: engine dies. A solitary neutron star rotating once every twenty
Speaker 3: minutes should be well past the death line.
Speaker 2: Wow.
Speaker 3: It should be dead cold and entirely silent in the
Speaker 3: radio spectrum.
Speaker 2: Okay, so we were basically looking at an old, rusted,
Speaker 2: slow moving bicycle, but it was somehow producing the roaring,
Speaker 2: deafening engine sound of a Formula one race car.
Speaker 3: That is an incredibly apt analogy. Yes, we were observing
Speaker 3: these massive energetic radio waves that are established universally accepted
Speaker 3: understanding of physics says absolutely cannot exist if the source
Speaker 3: is just a solitary, slowing neutron star.
Speaker 2: But the telescope data isn't lying right like the burst
Speaker 2: is real.
Speaker 3: Burst is very real.
Speaker 2: So if the bicycle cannot possibly make the roaring engine
Speaker 2: sound on its own, I mean it just physically can't.
Speaker 2: It means the bicycle isn't alone. Someone else has to
Speaker 2: be driving right alongside it with a sports car engine bingo.
Speaker 3: That exact realization is what forced the entire astronomical community
Speaker 3: to rethink the paradigm. If a single solitary dead star
Speaker 3: could possibly be responsible for these massive slow bursts, we
Speaker 3: had to be looking at a completely different kind of
Speaker 3: cosmic machinery.
Speaker 2: And that paradigm shift is what brings us to the
Speaker 2: monumental discovery of this system right s gap Ja, seventeen
Speaker 2: forty five.
Speaker 3: Yes, exactly.
Speaker 2: Let's talk about ASKAP for a second, because this is
Speaker 2: the observatory that finally caught one of these things in
Speaker 2: the act.
Speaker 3: It is so s GAP stands for the Australian Square
Speaker 3: Kilometer Array Pathfinder. That's a healthful it is. It's an
Speaker 3: array of thirty six radio dish antennas spread out across
Speaker 3: the remote outback of Western Australia, and it's operated by CSIRO,
Speaker 3: which is the National science agency there.
Speaker 2: Okay, thirty six dishes.
Speaker 3: Right, Instead of one massive monolithic dish, these thirty six
Speaker 3: dishes work together as a single incredibly sensitive instrument through
Speaker 3: a process called interferometry.
Speaker 2: So they link them all up.
Speaker 3: Yes, it essentially allows astronomers to survey huge swaths of
Speaker 3: the sky with incredible speed and detail.
Speaker 2: And they use this to spot a brand new long
Speaker 2: period radio transient.
Speaker 3: They did. But you know what makes ASKAP JAY seventeen
Speaker 3: forty five the true turning point this entire field of
Speaker 3: study isn't just that they found another ticking radio source.
Speaker 3: It's what the astronomers did immediately after they found it.
Speaker 3: For the very first time, they managed to coordinate a
Speaker 3: massive multi wavelength observation campaign.
Speaker 2: Multi wavelength, meaning they didn't just use radio exactly.
Speaker 3: They didn't just listen to the radio waves and should
Speaker 3: look at the system using X ray telescopes and optical
Speaker 3: telescopes simultaneously, which.
Speaker 2: Just from a logistical standpoint has to be a monumental headache.
Speaker 2: I mean, you can't just walk outside your house with
Speaker 2: three different sets of binoculars.
Speaker 3: Oh, it is a phenomenal feed of coordination. I mean,
Speaker 3: think about what is required here. You have the radio
Speaker 3: array tracking the target from the ground in Australia. To
Speaker 3: get optical visible light data, you need to coordinate with
Speaker 3: massive ground based observatories, perhaps in Chile or Hawaii, and
Speaker 3: literally prey that the weather holds and that the target
Speaker 3: is above the horizon during their specific night.
Speaker 2: No man, the weather. I didn't even think about that.
Speaker 3: It ruins observations all the time. And for X rays,
Speaker 3: our atmosphere entirely absorbs X rays from.
Speaker 2: Space, which is great for human health.
Speaker 3: Very great for us, but it's terrible for astronomy. So
Speaker 3: to observe X rays you have to secure observation time
Speaker 3: on billion dollar space satellites orbiting the Earth.
Speaker 2: So uch a book satellite time too, Yeah.
Speaker 3: And getting all of these ainked highly demanded instruments. To
Speaker 3: point at the exact same microscopic coordinate in the sky
Speaker 3: at the exact same minute requires years of proposals and
Speaker 3: just a staggering amount of luck.
Speaker 2: But they pulled it off. They stared at the smog
Speaker 2: with every type of lens humanity has built. And what
Speaker 2: did they actually see?
Speaker 3: They saw the complete picture. Acecap j seventeen forty five
Speaker 3: wasn't just emitting radio bursts. It was emitting both radio
Speaker 3: and X ray.
Speaker 2: Bursts at the same time.
Speaker 3: Yes, and crucially, those bursts were repeating in absolute perfect
Speaker 3: synchronization with the orbital motion of the system.
Speaker 2: So they didn't just find a suspect. They caught it
Speaker 2: on multiple cameras from different angles, all time stamped.
Speaker 3: Exactly if we connect this to the bigger picture. The
Speaker 3: researchers themselves referred to this multi wavelength detection as the
Speaker 3: Rosetta Stone.
Speaker 2: Like the actual historical artifact from.
Speaker 3: Egypt, exactly that for centuries historians were completely paralyzed by
Speaker 3: ancient Egyptian hieroglyphs.
Speaker 2: Right, they couldn't read them at all.
Speaker 3: They were looking at these beautiful, intricate symbols, but they
Speaker 3: had absolutely no underlying framework to understand what they meant.
Speaker 2: It was just visual noise until the stone.
Speaker 3: Right, because the Rosetta Stone featured the exact same decree
Speaker 3: written in three distinct scripts, ancient Greek, which scholars could
Speaker 3: fluently read, Demotic and Egyptian.
Speaker 2: Hieroglyphs, so they just lined them up.
Speaker 3: Because the underlying message was identical across all three, they
Speaker 3: could finally use the Greek to crack the code of
Speaker 3: the hieroglyphs.
Speaker 2: Okay, So in this cosmic scenario, the three scripts are
Speaker 2: the radio waves, the X rays, and the optical visible light.
Speaker 2: Exactly for thirty years, these long period transients have been
Speaker 2: speaking exclusively in radio waves, a language that made absolutely
Speaker 2: no physical sense to us because the solitary pulsar math didn't.
Speaker 3: Work right, It was just noise we couldn't decipher.
Speaker 2: But now, because ascop j seventeen forty five is speaking
Speaker 2: in all three wavelengths spiultaneously, we can use the X
Speaker 2: ray and optical data to translate the radio signal.
Speaker 3: You've got it perfectly, and that translation allowed them to
Speaker 3: definitively identify the en engine. And the engine is a
Speaker 3: Scapja seventeen forty five is not a solitary pulsar. It
Speaker 3: is a cataclysmic variable, specifically in a creating white dwarf
Speaker 3: binary system.
Speaker 2: Okay, here's where it gets really interesting. We have unmasked
Speaker 2: the suspect. We know the engine is an accreting white
Speaker 2: dwarf binary, but what does that actually mean. Let's dissect
Speaker 2: the physical anatomy of the system, because reading about it
Speaker 2: it is just wild, it really is.
Speaker 3: So we have to look at the two distinct stars
Speaker 3: involved in this binary dance player. One is the white dwarf. Okay, Now,
Speaker 3: earlier we discussed neutron stars, which are born from the
Speaker 3: explosive death of massive stars. A white dwarf is also
Speaker 3: a dead star, but it comes from a much more
Speaker 3: common origin like our son. Exactly like our son, when
Speaker 3: a lower mass star reaches the end of its life,
Speaker 3: it doesn't explode in a violent supernova. It gently puffs
Speaker 3: off its outer layers over time, leaving behind this dense,
Speaker 3: intensely hot, slowly cooling core.
Speaker 2: And that core is the white dwarf. Yes, so it's dense,
Speaker 2: but not you know, a tea spoon weighing a mountain
Speaker 2: dense like the neutron star.
Speaker 3: Right, it's not quite that extreme. It has roughly the
Speaker 3: mass of our Sun, but it squeezed down into a
Speaker 3: sphere about the size of the Earth.
Speaker 2: Okay, so still incredibly dense.
Speaker 3: Oh the gravity is immense, yes, yeah, but it isn't
Speaker 3: governed by the extreme quantum weirdness of a neutron star. Now,
Speaker 3: player two in this system is a low mass red
Speaker 3: dwarf star.
Speaker 2: A red dwarf so this one isn't dead.
Speaker 3: No, this is a living star. It is actively fusing hydrogen.
Speaker 3: But it is much smaller, cooler, and dimmer than our Sun.
Speaker 2: So we have a dead, cooling Earth sized core and
Speaker 2: a living small red star. And the keyword here is binary.
Speaker 2: They are orbiting each.
Speaker 3: Other, orbiting incredibly closely, so closely in fact, that they
Speaker 3: cross a critical gravitational threshold known as the rochlobe the
Speaker 3: row schlobe.
Speaker 2: Okay, what happens when they cross that threshold.
Speaker 3: Well, it initiates a process of intense stellar theft sellar theft.
Speaker 3: I love that it's the most accurate term. Gravity is
Speaker 3: essentially a battle of mass and distance. Because these two
Speaker 3: stars are orbiting in such tight proximity, the gravitational pull
Speaker 3: of the ultra dense white dwarf on the side of
Speaker 3: the red dwarf facing it becomes stronger than the red
Speaker 3: dwarf's own ability to hold onto its gas.
Speaker 2: Oh wow, So it's literally overpowering the other star's gravity completely.
Speaker 3: The white Dwarf's gravity physically breaches the red Dwarf's atmosphere
Speaker 3: and begins to siphon the euder layers of hydrogen plasma
Speaker 3: right off the living star, just ripping it away. Yes,
Speaker 3: this process of drawing in material is what we call accretion.
Speaker 2: It's a literal cosmic vampire. You have this undead, cooling
Speaker 2: stellar corpse constantly feeding off the atmosphere of its smaller
Speaker 2: living companion just to generate these massive bursts of energy.
Speaker 3: Vampire's a great analogy.
Speaker 2: And it's not a gentle process, is it, Like, it's
Speaker 2: not just politely sipping the plasma.
Speaker 3: Oh no, it is breathtakingly violent. As the plasma is
Speaker 3: ripped away from the red dwarf, it doesn't just fall
Speaker 3: straight down onto the white dwarf like rain. Why not
Speaker 3: Because both stars are orbiting each other, right, So the
Speaker 3: stolen material has angular momentum. It's moving sideways as it falls.
Speaker 1: Oh.
Speaker 2: Right, it's spinning exactly, so.
Speaker 3: It spirals inward, forming this massive, swirling, flattened funnel of
Speaker 3: gas known as an accretion disc around the equator of
Speaker 3: the white dwarf, like.
Speaker 2: The rings of Saturn, but made of superheated plasma.
Speaker 3: Yes, and moving way way faster. The material in this
Speaker 3: disc is orbiting at immense speeds, constantly rubbing against itself,
Speaker 3: which creates staggering amounts of friction and kinetic energy.
Speaker 2: Man this entirely redefines the math. We aren't looking at
Speaker 2: a single neutron star just spinning in isolation and running
Speaker 2: out of juice. The energy powering these long period transients
Speaker 2: is coming from the active, violent collision of material being
Speaker 2: passed from one star to another exactly.
Speaker 3: The engine is the interaction, not just the rotation.
Speaker 2: But wait, if the white dwarf is constantly feeding like this,
Speaker 2: is it eventually going to devour the Red dwarf intoirely
Speaker 2: How long can a vampiric dance like this actually last?
Speaker 3: It is an incredibly long drawn out process. These cataclysmic
Speaker 3: variable systems can persist for millions, sometimes billions of.
Speaker 2: Years, billions just slowly eating it.
Speaker 3: Yep, it is a very slow, steady drain. As the
Speaker 3: red dwarf loses mass, the entire orbital dynamic of the
Speaker 3: two stars actually shifts to compensate.
Speaker 2: They adjust their orbit.
Speaker 3: Basically, Yes, they move slightly further apart or closer together,
Speaker 3: depending on the mass transfer. But over the time scales
Speaker 3: that humanity operates on, it acts as a remarkably stable,
Speaker 3: relentless feeding engine.
Speaker 2: Okay, so we have the mechanism, the steady flow of
Speaker 2: stolen plasma. But how does this meal of red dwarf
Speaker 2: gas actually produce the specific, perfectly timed flashes of X
Speaker 2: ray and radio light that we detect Because friction makes
Speaker 2: heat but doesn't make radio waves.
Speaker 3: Great question. Let's start with the X rays because the
Speaker 3: physics there are directly tied to the friction we just discussed.
Speaker 2: Okay, lay it on me.
Speaker 3: As the stolen material spirals deeper and deeper into the
Speaker 3: accretion disk, getting closer and closer to the surface of
Speaker 3: the white dwarf, the gravitational pull gets stronger and the
Speaker 3: speed of the plasma increases. Right, all that internal friction
Speaker 3: heats the gas to extreme temperatures. We're talking millions of degrees.
Speaker 2: Millions of degrees just from gas running against gas.
Speaker 3: Yes, the kinetic energy is just enormous, and when gas
Speaker 3: gets that extraordinarily hot, it radiates high energy light.
Speaker 2: So that's the X rays exactly.
Speaker 3: The kinetic energy of the falling plasma is converted into
Speaker 3: thermal energy the inner edges of that accretion disk, and
Speaker 3: the actual point where the material finally slams onto the
Speaker 3: surface of the white dwarf the impact zund right, that
Speaker 3: zone becomes so superheated that it glows brilliantly in the
Speaker 3: X ray spectrum. The X rayser essentially the thermal signature
Speaker 3: of the destruction.
Speaker 2: Okay, the X rays make perfect sense to me. It's
Speaker 2: the heat of the friction. But what about the radio waves?
Speaker 2: Because we established earlier that a slow spinning dead star
Speaker 2: shouldn't be making radio bursts.
Speaker 3: Right, this is where the true brilliance of the binary
Speaker 3: discovery comes into play. The radio light isn't caused by
Speaker 3: the thermal heat of the gas at all, It's not. No,
Speaker 3: it is caused by the interaction between highly energetic charged
Speaker 3: particles and intensely strong magnetic fields.
Speaker 2: Okay, so we're back to magnets. Both of these stars
Speaker 2: are highly magnetic.
Speaker 3: Yes, profoundly magnetic A white torset can have a magnetic
Speaker 3: field thousands, sometimes millions of times stronger than an MRI
Speaker 3: machine in a hospital on.
Speaker 2: Earth, millions of times stronger than an MRI, and MRIs
Speaker 2: can rip chairs across a room exactly.
Speaker 3: It's a field strength we literally cannot fathom. And the
Speaker 3: red dwarf is also magnetically active, churning out his own
Speaker 3: complex magnetic field lines.
Speaker 2: Okay, so instead of the clunky idea of like sparks
Speaker 2: flying off silverware while eating, which is what I was
Speaker 2: picturing earlier, let me try a completely different analogy here,
Speaker 2: go for it. It sounds more like a massive cosmic
Speaker 2: hydroelectric dam.
Speaker 3: Ooh, I like where this is going?
Speaker 2: Right? So the physical water crashing down the spillway, the
Speaker 2: sheer gravity and friction of the plasma falling, that's your heat,
Speaker 2: your X rays. Yes, But inside the dam you have
Speaker 2: these invisible magnetic turbines spinning. The flow of the water
Speaker 2: forces them to interact, and that invisible magnetic tension is
Speaker 2: what actually generates the electricity or in this case, flings
Speaker 2: the radio waves out across the galaxy.
Speaker 3: That is a significantly better and much more physically accurate visualization,
Speaker 3: I might steal that the kinetic flow of the plasma
Speaker 3: is interacting with the invisible magnetic architecture of the system.
Speaker 2: There's a term for that, right yes.
Speaker 3: In astrophysics, this specific mechanism of generating radio waves is
Speaker 3: called synchrotron radiation.
Speaker 2: Synchrotron radiation, how does that work in this And because
Speaker 2: this whole system is locked in a strict binary orbit,
Speaker 2: the geometry of how those magnetic fields align and how
Speaker 2: the plasma flows repeats itself perfectly every single time the
Speaker 2: stars complete a revolution.
Speaker 3: Precisely as the stars swing around their common center of
Speaker 3: gravity are viewing angle from Earth changes, the magnetic fields align,
Speaker 3: the plasma gets a accelerated the synchrotron radiation blasts outward,
Speaker 3: and Earth's telescopes pick up a massive, booming radio pulse.
Speaker 2: And then twenty minutes later the.
Speaker 3: Stars complete another orbit, that geometry realigns and boom another pulse.
Speaker 2: That is incredible.
Speaker 3: It is a perfectly timed, incredibly complex machine powered entirely
Speaker 3: by gravity and magnetism.
Speaker 2: Which completely solves the mystery. It isn't a single impossibly
Speaker 2: slow pulsar just breaking the laws of physics. It is
Speaker 2: a dynamic interacting binary system functioning exactly as the laws
Speaker 2: of physics dictate.
Speaker 3: It's all just physics doing what physics does.
Speaker 2: So what does this all mean for the broader world
Speaker 2: of astronomy. Why is scap JAY seventeen forty five such
Speaker 2: a landmark moment beyond just you know, solving a really
Speaker 2: cool puzzle.
Speaker 3: Well, it changes the future of how we study the
Speaker 3: galaxy because it gives us an unparalleled baseline. We now
Speaker 3: know for a fact that an accreting white dwarf binary
Speaker 3: can produce these long period twenty minute radio transient.
Speaker 2: The Rosetta stone is fully trand.
Speaker 3: Exactly because we have this complete picture spanning radio, optical
Speaker 3: and X ray data for ace gap J seventeen forty five,
Speaker 3: astronomers can now look back.
Speaker 2: At the archives, look at the other eleven sources.
Speaker 3: Right, They can look at all the other mysterious isolated
Speaker 3: radio transients that are hiding deep behind the galactic dust,
Speaker 3: the ones where we only have the radio horn and
Speaker 3: absolutely no X ray or optical data to back.
Speaker 2: It up, so they can essentially reverse engineer the suspect.
Speaker 3: They can definitively say, look, we can't see the X
Speaker 3: rays because the interstellar smog is too thick. But because
Speaker 3: the periodicity, the polarization, and the exact shape of these
Speaker 3: radio waves look exactly like our baseline ace gap system,
Speaker 3: we can infer that we are looking at another cosmic
Speaker 3: vampire system.
Speaker 2: That is such a powerful tool.
Speaker 3: It is a vital diagnostic tool for exploring the hidden,
Speaker 3: dust obscured regions of the Milky Way.
Speaker 2: But this isn't just about cataloging stars, right, There's a
Speaker 2: broader application for physics itself here.
Speaker 3: Oh, definitely. This raises an important point about the nature
Speaker 3: of astrophysics in general. Exploring these mechanisms essentially turns deep
Speaker 3: space into a pristine extreme physics laboratory. How so, Well,
Speaker 3: on Earth, we are profoundly limited by our environment and
Speaker 3: our technology.
Speaker 2: Right, we can only build things so big, exactly.
Speaker 3: We've been billions of dollars building massive facilities like the
Speaker 3: Large Hadron Collider at Cerne just to smash tiny particles together.
Speaker 3: Or we build massive fusion tocamacs trying to contain superheated
Speaker 3: plasma with artificial magnetic fields.
Speaker 2: Which is incredibly hard to do.
Speaker 3: Apparently, it's tremendously difficult, and those earthly experiments are incredible
Speaker 3: don't get me wrong, but they are limited. We cannot
Speaker 3: recreate this shear scale, the density or the magnetic field
Speaker 3: strength of a white dwarf star in a laboratory in Switzerland.
Speaker 2: No, definitely not.
Speaker 3: But the universe has already built these ultimate laboratories out
Speaker 3: in the cosmos for us. We have white dwarfs acting
Speaker 3: as natural sustained particle accelerators, generating forces and plasma flows
Speaker 3: we can barely even comprehend, and.
Speaker 2: They've been running for millions of years.
Speaker 3: The experiment has been running flawlessly for millions of years.
Speaker 3: We just needed to develop the instruments to record the
Speaker 3: data and the context to actually read the dials on
Speaker 3: the machinery.
Speaker 2: So we're just watching the results of an experiment we
Speaker 2: didn't have to build exactly.
Speaker 3: By observing how synchrotron radiation behaves when plasma subjected to
Speaker 3: magnetic fields thousands of times stronger than our best technology,
Speaker 3: we might unlock fundamental secrets about electromagnetism and fluid dynamics
Speaker 3: that apply far beyond just looking at stars.
Speaker 2: Like things we could use here on Earth.
Speaker 3: Potentially. Yes, the knowledge gained from observing extreme space phenomena
Speaker 3: frequently filters down to influence plasma physics, quantum mechanics, and
Speaker 3: our fundamental understanding of how energy and matter interact. Wow,
Speaker 3: this single discovery bridges observational astronomy and theoretical physics in
Speaker 3: a really profound way.
Speaker 2: It is a massive triumph of observation, global coordination, and
Speaker 2: just sheer scientific patients. Let's take a breath and recap
Speaker 2: this incredible journey we've been on today. Sure darted by
Speaker 2: staring into the impenetrable dusty smog of the center of
Speaker 2: the Milky Way, just listening to these impossibly slow rhythmic
Speaker 2: flashes of radio light.
Speaker 3: The car horn in the smug the car horn.
Speaker 2: And we hit a massive theoretical wall. When our established
Speaker 2: physics proved that a solitary, dying neutron star couldn't possibly
Speaker 2: be spinning that slowly and still producing radio waves. The
Speaker 2: engine should have been dead, stone dead. But instead of
Speaker 2: throwing out the data, astronomer's martial telescopes across the globe
Speaker 2: and in orbit peered through different wavelengths of light simultaneously
Speaker 2: and finally unmasked the true engine. We aren't looking at
Speaker 2: a lonely dying star, not at all. We are looking
Speaker 2: at a vampiric white dwarf locked in a violent magnetic
Speaker 2: dance with a living companion, constantly siphoning off its atmosphere
Speaker 2: to power a massive, synchronized cosmic generator.
Speaker 3: It serves as a stark reminder that the universe is
Speaker 3: rarely as simple as a solitary object acting in total isolation.
Speaker 2: It's all connected.
Speaker 3: The cosmos is incredibly dynamic, deeply interactive, and it constantly
Speaker 3: requires us to adapt, discard old assumptions, and build completely
Speaker 3: new frameworks when the evidence demands it.
Speaker 2: It truly does. And as we wrap up this journey,
Speaker 2: I want to leave you with a final lingering thought
Speaker 2: to ponder long after the audio stops today. Think about
Speaker 2: the sheer scale of the timeframe here. These massive energetic
Speaker 2: signals were flashing in the dark for thirty years before
Speaker 2: humanity finally gathered the right combination of tools to understand them.
Speaker 3: Thirty years of just listening to the metrono.
Speaker 2: Exactly if it took coordinating billion dollar radio arrays on
Speaker 2: Earth with X ray satellites in orbit just to realize
Speaker 2: that a violent stellar feeding frenzy was happening right in
Speaker 2: our own galactic neighborhood. What other invisible extreme forces are
Speaker 2: silently shaping the universe right now.
Speaker 3: Oh, there's so much we don't know.
Speaker 2: What other massive engines are ticking away in the dark,
Speaker 2: passing right through us, just waiting for us to develop
Speaker 2: the correct lens to finally see them. Maybe the next
Speaker 2: time you look up at the darkest, dust choked part
Speaker 2: of the night sky, you won't just see an empty void.
Speaker 2: You'll wonder what invisible giants are dancing right behind the veil.