Speaker 1: Welcome to Bedtime Astronomy. Explore the wonders of the cosmos
Speaker 1: with our soothing Bedtime Astronomi 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: We talk a lot on this deep dive about stars dying,
Speaker 2: which you know, sounds inherently dramatic. It does, but the
Speaker 2: universe doesn't really do simple melodrama. It deals in a
Speaker 2: complexity and just unimaginable violence exactly. And we're not just
Speaker 2: talking about a star dying here. We're talking about a
Speaker 2: whole category of cosmic events that well, that we may
Speaker 2: have been fundamentally misclassifying.
Speaker 3: For decades, or maybe a better way to put it
Speaker 3: is that the cosmos has just introduced a new hybrid
Speaker 3: category of extreme.
Speaker 2: Violence, a new category entirely.
Speaker 3: Yeah, we dove into a deep stack of sources all
Speaker 3: about this one cosmic event officially called at twenty twenty
Speaker 3: five oders, and this event, it, frankly, it acted like
Speaker 3: two different things at want.
Speaker 2: A massive star explosion, and a dead star merger.
Speaker 3: At the same time. It's presented astronomers with this really
Speaker 3: compelling paradox. It fundamentally challenges our rule book for how
Speaker 3: stars are supposed to die.
Speaker 2: So our mission today is to unpack.
Speaker 3: That it is. We're going to synthesize all this confusing
Speaker 3: contradictory data, the gravitational waves on one hand and the
Speaker 3: lightweights on the other, to understand the leading hypothesis, the
Speaker 3: birth of a brand new, first of its kind phenomenon
Speaker 3: called a super killinova.
Speaker 2: You know, I find it endlessly fascinating when the universe
Speaker 2: just throws out a plot twist, something that forces us
Speaker 2: to rewrite the physics textbooks.
Speaker 3: It happens more often than you'd think.
Speaker 2: But before we get there, we really need to quickly
Speaker 2: contextualize these cosmic blasts for you, because understanding the established difference,
Speaker 2: the different between the two main types of explosion is
Speaker 2: just crucial to grasping why eight twenty twenty five foals
Speaker 2: cause such an astronomical identity crisis.
Speaker 3: That's absolutely the right place to start. Think of it
Speaker 3: like this, stellar evolution has two massive endpoints, and each
Speaker 3: one is responsible for seating the universe with the basic
Speaker 3: chemistry that makes up well everything, including us.
Speaker 2: The first and probably the one people have heard of,
Speaker 2: is the supernova.
Speaker 3: Yes, this is the death of the behemoths. When the
Speaker 3: most massive stars, you know, the ones far bigger than
Speaker 3: our sun, burn through their fuel. They collapse violently, and
Speaker 3: then they explode.
Speaker 2: And that explosion seeds the universe with what exactly.
Speaker 3: Lighter heavy elements, so things like carbon, oxygen, nitrogen, all
Speaker 3: the way up the periodic table to iron. These are
Speaker 3: the elements that form the bulk of planets in life.
Speaker 3: They're essential, but they're kind of the common currency of
Speaker 3: stellar explosions. Yeah, it's a stellar collapse event.
Speaker 2: Okay, so if supernova are the common currency, killinova they're
Speaker 2: the mint. This is where the universe forges the really
Speaker 2: rare and fancy stuff.
Speaker 3: That's a great way to put it precisely. Killinova are
Speaker 3: fundamentally different. They aren't star deaths. They're dead star mergers.
Speaker 2: So not a collapse, a collision collision.
Speaker 3: It happens when two ultra dense, deceased stars, usually neutron stars,
Speaker 3: spiral into each other and just smash together at incredible speeds.
Speaker 3: And this is the only known environment in the universe
Speaker 3: where you get the right combination of insane heat density
Speaker 3: and a massive continuous flood of free neutrons.
Speaker 2: Which allows for something called our process.
Speaker 3: The rapid neutron capture process or our process yep.
Speaker 2: And why is that process so important for us here
Speaker 2: on Earth?
Speaker 3: Because our process is how the truly heaviest elements get forged.
Speaker 3: We're talking gold, platinum, uranium, the good stuff, all the
Speaker 3: precious metals, the radioactive components that are fundamental building blocks
Speaker 3: of planets. They are incredibly rare, born from these highly
Speaker 3: violent events and they're just astronomically significant. So when you
Speaker 3: find these elements here on Earth, you know that gold
Speaker 3: in your ring, it's the shrapnel from a Killinova that
Speaker 3: happened a long long time ago.
Speaker 2: The physics of the explosion dictates the chemistry of the universe.
Speaker 3: That's it.
Speaker 2: So to really appreciate just how strange at twenty twenty
Speaker 2: five Felatse was, we have to start with the baseline,
Speaker 2: the universally accepted gold standard Killinova.
Speaker 3: Which brings us to the blueprint of stellar collisions Killanova
Speaker 3: one oh one, And.
Speaker 2: There's one event that really stands out.
Speaker 3: The benchmark event absolutely, The one that proved the theory
Speaker 3: of Kelenova was GW one seven zero eight seventeen. That
Speaker 3: was back in August twenty seventeen.
Speaker 2: Before that, the idea was purely theoretical.
Speaker 3: Purely theoretical. The idea of two neutron stars merging and
Speaker 3: forging gold was just a model. This event was historic
Speaker 3: because it was the first and until our new friend
Speaker 3: at twenty twenty five latchers, yeah, the only time we
Speaker 3: had an unambiguously confirmed detection. It included both gravitational waves
Speaker 3: and light waves.
Speaker 2: That dual detection. Seeing the ripples in space time and
Speaker 2: then the.
Speaker 3: Flash of light, it changed astronomy forever.
Speaker 2: Okay, can we zero in on the gravitational wave part
Speaker 2: for a second. What exactly did those ripples in space
Speaker 2: time tell us about the objects before any telescopes even
Speaker 2: looked up?
Speaker 3: Right? So that's the real power of Ligo and Virgo,
Speaker 3: the detectors. They pick up this minute stretching and squeezing
Speaker 3: of space time. It's caused by the incredible acceleration of
Speaker 3: these neutron stars as they spiral into each other. It
Speaker 3: chirp signal, that's the one, and by analyzing the frequency
Speaker 3: in the amplitude of those incoming ripples, we can mathematically
Speaker 3: model the mass, the spin, even how far away the
Speaker 3: objects are.
Speaker 2: And for GW one seventy eight seventeen, what did that
Speaker 2: chirp say?
Speaker 3: The signal was clean, it was beautiful. It indicated the
Speaker 3: merger of two objects that were firmly in the expected
Speaker 3: mass range for neutron stars, somewhere between one point one
Speaker 3: and one point six times the mass of.
Speaker 2: Our sun, so perfectly normal neutron stars sextbook.
Speaker 3: And that initial signal immediately triggered an alert that went
Speaker 3: out to the world's optical telescopes, giving them a general
Speaker 3: direction in the sky to start looking.
Speaker 2: And what did they see? What was that unique visual
Speaker 2: fingerprint that confirmed, yes, this is the Kilanova the gravity
Speaker 2: waves told us about.
Speaker 3: They saw a rapid eruption of light. It peaked and
Speaker 3: then faded very very fast over a matter of days,
Speaker 3: maybe a week. And most importantly, it glowed this distinct
Speaker 3: deep crimson.
Speaker 2: Color red so quick and crimson that.
Speaker 3: Became the universal signature. If you're looking for a killinova,
Speaker 3: that's what you're looking for.
Speaker 2: And this is where we get to the really beautiful
Speaker 2: complex atomic chemistry. The color itself, the red color. The
Speaker 2: explosion is the smoking gun. It proves that gold and
Speaker 2: uranium are being made.
Speaker 3: It is this is the cool part.
Speaker 2: So walk us through the mechanism of that deep red glow.
Speaker 2: Why red.
Speaker 3: It's caused by something called the lanthanide curtain. So you
Speaker 3: have these extremely heavy elements being produced in the blast.
Speaker 3: Elements like the lanthanides, which include europium and of course gold, platinum, uranium.
Speaker 3: They all have these massive, really complex atomic nuclei, and
Speaker 3: that means that means they have a chaotic, dense arrangement
Speaker 3: of electron energy levels.
Speaker 2: Okay, so there are a lot more places for photons,
Speaker 2: for light particles to interact with the atom.
Speaker 3: Precisely, these elements, which are just churned out in the
Speaker 3: blast create this dense, opaque shell around the merger. So
Speaker 3: when light tries to pass through this cloud of newly
Speaker 3: minted heavy atoms, those complex electron structures are incredibly efficient
Speaker 3: at absorbing or blocking high energy photons.
Speaker 2: The blue light, the ultraviolet light exactly.
Speaker 3: Think of it like a very specific, very thick filter.
Speaker 3: The blue high energy light gets immediately trapped or scattered
Speaker 3: by the chaos of all these heavy elements.
Speaker 2: But the red light gets through.
Speaker 3: Exactly the lower energy light. The light at the red
Speaker 3: and infrared end of the spectrum is much less susceptible
Speaker 3: to this. It manages to pass through the dense debris
Speaker 3: cloud relatively unimpeded, So the light we end up observing
Speaker 3: is dramatically skewed toward those red wavelengths.
Speaker 2: Giving the Killinova its signature rapidly fading red.
Speaker 3: Glow and GW one seven zero eight seventeen established that
Speaker 3: perfectly dual detection rapid light curve and that telltale crimson
Speaker 3: color signaling that super heavy elements were being made. That
Speaker 3: is the classic established signature.
Speaker 2: Okay, let's just lay out that standard model one more time.
Speaker 3: GW one seven zero eight seventeen is the classic Killanova.
Speaker 3: You get the gravitational ways, you get the light, It
Speaker 3: fades fast, it glows red because of the heavy elements
Speaker 3: blocking the blue light. That's our perfect confirmed baseline.
Speaker 2: That's the blueprint.
Speaker 3: What happens when a new event looks exactly like that
Speaker 3: until the light curve takes a sudden, sharp and completely
Speaker 3: unexpected left turn.
Speaker 2: And that sudden turn brings us to the duel alert
Speaker 2: twenty twenty five sive arrest enters the scene. Because the
Speaker 2: initial observations, I mean they mirrored GW one seven zero
Speaker 2: eight seventeen almost perfectly. It gave astronomers this massive sense
Speaker 2: of deja vus. The countdown began on August eighteenth, twenty
Speaker 2: twenty five. That's when the gravitational wave trigger S two
Speaker 2: five zero eight eighteen K went off.
Speaker 3: Yeah, the alert went across the whole global network. The
Speaker 3: twin Lego detectors in the US, Virgo in Italy, and
Speaker 3: the whole international collaboration that includes Kjry and Japan. All
Speaker 3: of them picked up the signal.
Speaker 2: And they immediately sent out an.
Speaker 3: Alert immediately to the entire astronomical community saying, hey, a
Speaker 3: merger has occurred, and it's important to understand the scale
Speaker 3: of this. When an alert like this comes in, dozens
Speaker 3: of observatories large and small, they drop whatever they are doing.
Speaker 3: They re aim their telescopes and start scanning the sky
Speaker 3: region provided by the.
Speaker 2: Network because the window to catch the light is tiny.
Speaker 3: It's just a few days.
Speaker 2: But right from the start, the analysis of the gravitational
Speaker 2: wave data itself, it revealed something crucial that set this
Speaker 2: alert apart from GW one to seven AY eight seventeen.
Speaker 2: There was an immediate curiosity, maybe even a confusion about
Speaker 2: what was actually colliding.
Speaker 3: Yes, the signal was clearly a merger, no doubt about that,
Speaker 3: but the mathematical modeling of the waves indicated that at
Speaker 3: least one of the colliding objects was unusually tiny. The
Speaker 3: merger involved objects that were less massive than a typical
Speaker 3: neutron star.
Speaker 2: Specifically how tiny.
Speaker 3: Specifically, the data was consistent with at least one of
Speaker 3: the compon It's having a mass less than one solar mass.
Speaker 2: Wait, less massive than our own sun.
Speaker 3: Exactly subsolar mass. This immediately raised a giant red flag
Speaker 3: or maybe a beacon of interest for theorists.
Speaker 2: Because that's not supposed to happen.
Speaker 3: The standard lower limit for a stable neutron star is
Speaker 3: around one point two solar masses, so to detect a
Speaker 3: subsolar mass object in a merger, it meant we were
Speaker 3: potentially seeing something brand new about how stars evolve or
Speaker 3: how their remnants form.
Speaker 2: So even if the signal wasn't super strong right.
Speaker 3: As one of the LEGO team members noted, even if
Speaker 3: it wasn't the highest confidence alert ever, the truly intriguing
Speaker 3: nature of the objects that subsolar component. They got everyone's
Speaker 3: attention immediately, so.
Speaker 2: The gravity wave data gave them a rough map of
Speaker 2: where to look, which let the optical telescopes follow up
Speaker 2: incredibly fast.
Speaker 3: And that rapid response is just critical for catching these
Speaker 3: things before they disappear.
Speaker 2: And hours later, yeah, they found it.
Speaker 3: Hours later, This Wiki Transient Facility or ZTF at Palmar
Speaker 3: Observatory in California, they nailed the location. ZTF is basically
Speaker 3: designed for this kind of astronomical triosh. It scans huge
Speaker 3: areas of the sky really fast, looking for things to change, and.
Speaker 2: It found a rapidly fading red object.
Speaker 3: A rapidly fading red object about one point three billion
Speaker 3: light years away. It was initially tagged with a ZTF
Speaker 3: name and then later officially designated eight twenty twenty five flats.
Speaker 2: Location confirmed one point three billion light years away and
Speaker 2: the initial observations matched the Killanova blueprint perfectly.
Speaker 3: Absolutely did I mean this is where the initial belief
Speaker 3: that this was a standard Killanova really got cemented. About
Speaker 3: a dozen other telescopes jumped on it, cag and Hawaii,
Speaker 3: Wendelstein in Germany. The entire grouth network of observatories. They
Speaker 3: all pointed their mirrors at.
Speaker 2: The target and they all confirmed the same thing.
Speaker 3: They all confirmed it. The light eruption faded fast and
Speaker 3: it glowed at those signature red wavelengths.
Speaker 2: So, if you're an astronomer in those first few days,
Speaker 2: you're looking at a textbook Killinova. You've got the gravity
Speaker 2: waves from a merger. You've got the light signature confirming
Speaker 2: heavy elements being made, glowing red, fading fast.
Speaker 3: You're thinking, we've got it. This is the long awaited
Speaker 3: second confirmed Killinova, a perfect echo of GW one sever
Speaker 3: eight aii in.
Speaker 2: It was textbook.
Speaker 3: It was textbook until that initial fading curve bottomed out
Speaker 3: and then did something utterly inexplicable for a killinova.
Speaker 2: And this is where the paradox really sets in the
Speaker 2: astronomical identity crisis, because days after that initial blast, the
Speaker 2: textbook definition was just shattered at twenty twenty five years,
Speaker 2: completely changed its signature.
Speaker 3: The initial fast red phase was perfectly consistent with the Killanova, right,
Speaker 3: but then the event's characteristics just reversed entirely. The Killanova
Speaker 3: should only fade. That's the physics of it. The radioactive
Speaker 3: material dispersed it and it cools down quickly.
Speaker 2: But instead of continuing to fade, at twenty twenty five,
Speaker 2: chills started to brighten again.
Speaker 3: It did, and not only did the brightness reverse course,
Speaker 3: but the light changed color. It decisively turned blue.
Speaker 2: So if the red light signals heavy complex atoms and
Speaker 2: that lanthanide curtain, blue lights signal something completely different.
Speaker 3: Completely different, faster moving material, less obscured, higher energy, which
Speaker 3: usually means lighter.
Speaker 2: Element than the spectrum analysis delivered the biggest shock of all.
Speaker 3: The spectra began to show the unmistakable presence of hydrogen,
Speaker 3: and that is the observation that truly truly confounded everyone.
Speaker 2: It's the ultimate contradition to the Kilinova model.
Speaker 3: It is neutron star mergers happen after the original stars
Speaker 3: have stripped off their outer gas envelopes. Are just these
Speaker 3: extremely dense neutron rich objects. A Killinova should not be
Speaker 3: generating any significant detectable amount of.
Speaker 2: Hydrogen, because hydrogen is what stars are made of.
Speaker 3: Exactly so the presence of hydrogen, that color shift to blue,
Speaker 3: and the renewed brightening, all of those are classic undeniable
Speaker 3: signs of a core collapse. Supernova, specifically a stripped envelope type.
Speaker 2: So let me get this straight. We have a clear
Speaker 2: gravitational wave signal that says dead star merger, we have
Speaker 2: an initial light curve that says killin nova, but then
Speaker 2: we have a secondary light curve that screams supernova.
Speaker 3: That's the paradox, and it created immediate widespread controversy and
Speaker 3: deep skepticism in the wider astronomical community.
Speaker 2: And that skepticism was rooted in fundamental physics.
Speaker 3: Right it was. Supernova from distant galaxies are generally not
Speaker 3: expected to generate enough detectable gravitational waves for Lego and
Speaker 3: virgo to pick up. A supernova explosion is, for the
Speaker 3: most part symmetric. The ways it produces tend to cancel
Speaker 3: each other out.
Speaker 2: But killinova mergers are the opposite.
Speaker 3: They're highly asymmetric and incredibly violent. They produce a very strong,
Speaker 3: very measurable gravitational wave signal.
Speaker 2: So if the optical signal turned out to be a supernova,
Speaker 2: the simplest explanation was that the two events were just unrelated.
Speaker 2: That eighteen to twenty twenty five full Is was just
Speaker 2: a typical ho hum supernova that happened to be in
Speaker 2: the same part of the sky as the gravitational wave signal.
Speaker 3: That's right, and based on the source material, this is
Speaker 3: precisely where many astronomers just lost interest.
Speaker 2: They just wrote it off as a coincidence herring they did.
Speaker 3: They concluded the initial killinova alert was a bust, that
Speaker 3: it was unrelated to the later optical brightening. They assumed
Speaker 3: the gravitational wave alert came from some invisible dark merger
Speaker 3: event and the supernova just happened to be nearby.
Speaker 2: But what about the odds of that, I mean, a
Speaker 2: distant supernova coincidentally appearing in the same gravitational wave map location.
Speaker 2: That has to be pretty low, right, How did the
Speaker 2: Celtech team argue against that?
Speaker 3: The probability of a chance alignment like that is low,
Speaker 3: you know, maybe one in one hundred thousand, but it's
Speaker 3: not astronomically impossible. Those gravitational wave mapping boxes are still
Speaker 3: pretty large areas of the sky. The issue was less
Speaker 3: about pure probability and more about Ockham's razor.
Speaker 2: The simplest explanation is usually the.
Speaker 3: Correct one, Right, A merger produces gravitational waves, a supernova
Speaker 3: produces light. If the light signal later looks unambiguously like
Speaker 3: a supernova. You just separate the two events.
Speaker 2: But the team, led by Caltech's Mancy Cosliwall she's the
Speaker 2: lead author of the key study, they insisted that something
Speaker 2: unusual was happening. They refused to just dismiss the connection.
Speaker 3: And their perseverance was based on this really deep, critical
Speaker 3: analysis of the data. They noted that the event it
Speaker 3: didn't look like an average supernova either. It was an
Speaker 3: odd ball as soon it had the unprecedented speed and
Speaker 3: the initial red phase of a killinova, but that was
Speaker 3: overlaid with the later powerful characteristics of a supernova. They
Speaker 3: saw that unusual dual phase light signature as evidence of
Speaker 3: a connection, not a coincidence.
Speaker 2: So the very fact that it didn't fit neatly into
Speaker 2: either category, not a classic killanova, not a classic supernova,
Speaker 2: that's what kept them pursuing it. The messiness of the
Speaker 2: data itself became the clue.
Speaker 3: Exactly, and that critical insight brings us to the hypothesis
Speaker 3: of the super killinova. This provides a framework for how
Speaker 3: one single cosmic event could execute a two part explosion,
Speaker 3: producing both that immediate merger signal and the later obscuring
Speaker 3: supernova signature.
Speaker 2: A killinova spurred on by a supernova. That's the idea
Speaker 2: and the core argument for the super kilinova hinges on
Speaker 2: connecting those two extremely strange clues that defy the standard models.
Speaker 2: The first one which we touched on is the nature
Speaker 2: of the colliding objects themselves.
Speaker 3: That's the lynchpin. The Lygovirgo data showed that at least
Speaker 3: one object in the merger was less massive than a
Speaker 3: typical neutron star, a subsolar mass neutron star. And this
Speaker 3: is the concept of the forbidden mass range, and it's
Speaker 3: a huge challenge to standard stellar physics.
Speaker 2: So why is that mass range, you know, less than
Speaker 2: one point two solar masses considered forbidden or so problematic
Speaker 2: for a stable neutron star.
Speaker 3: Okay, so we have to go back to the fundamental
Speaker 3: physics of extreme density. When a massive star dies, gravity
Speaker 3: collapses the core until the matter is so dense that
Speaker 3: electrons and protons are literally crushed together into neutrons.
Speaker 2: And it's the pressure from those neutrons that stops the collapse.
Speaker 3: Yes, it's called neutron degeneracy pressure. It's the quantum pressure
Speaker 3: from these tightly packed neutrons that halts the collapse and
Speaker 3: stabilizes the star forms a neutron star.
Speaker 2: It's basically the last line of defense against becoming a black.
Speaker 3: Hole, precisely, and to overcome the outward push of that
Speaker 3: pressure and stabilize the star, you need a critical amount
Speaker 3: of mass, and theoretical models, which have been corroborated by
Speaker 3: decades of observation, plays that lower limit. The minimum mass
Speaker 3: you need at around one point two times the mass.
Speaker 2: Of our Sun, and anything smaller than that.
Speaker 3: Anything smaller, according to standard models, just can't sustain the
Speaker 3: neutron star structure. It would either bounce back and never
Speaker 3: fully collapse, or it would form something far less dense,
Speaker 3: like a white dwarf.
Speaker 2: So if the gravitational wave signature is telling us that
Speaker 2: at least one of these colliding objects was significantly smaller
Speaker 2: than one point two solar masses, then the way that
Speaker 2: object was formed must have been fundamentally different from the
Speaker 2: standard model.
Speaker 3: That's the only logical conclusion. And theorists, including Brian Metzger
Speaker 3: at Columbia, had previously proposed ways for these tiny objects
Speaker 3: to exist, but they had never been observed before. They
Speaker 3: are the essenti missing piece of this whole superkillinova theory.
Speaker 2: We need a way to explain how the universe Strea
Speaker 2: so Metzker's team proposed two theoretical scenarios for how these
Speaker 2: subsolar neutron stars could be formed during a supernova. Let's
Speaker 2: start with the first one, fission, the idea of splitting
Speaker 2: the core.
Speaker 3: Okay, so in the fission scenario, you start with an
Speaker 3: incredibly massive star that is spinning extremely rapidly as it
Speaker 3: collapses and goes supernova. That rotation is key.
Speaker 2: It's all about the spin.
Speaker 3: It's all about the spin. Instead of the core collapsing
Speaker 3: neatly into one single remnant, the extreme centripetal forces, coupled
Speaker 3: with the instability of the core, cause the collapsing matter
Speaker 3: to split or fission into two tiny, separate subsolar mass
Speaker 3: neutron stars.
Speaker 2: So they're born not as one, but as twins, as.
Speaker 3: Twin tiny remnants orbiting each other immediately right inside the
Speaker 3: newly exploding star.
Speaker 2: And the second scenario fragmentation. That sounds like we're building
Speaker 2: a miniature solar system inside a dying star.
Speaker 3: That analogy is actually highly relevant in the fragmentation scenario. Again,
Speaker 3: you have a rapidly spinning star going supernova, but as
Speaker 3: the core collapses, the material forms an accretion disc around it.
Speaker 2: Like the disc that forms planets around a new star.
Speaker 3: Very similar. This disc is highly unstable and lumpy, and
Speaker 3: that lumpy disc material then fragments and coalesces. It lumps
Speaker 3: together into a tiny neutron star, much like a planet
Speaker 3: would form in a protoplanetary disc. Both of these scenarios
Speaker 3: fission and fragmentation. They rely critically on that progenitor star
Speaker 3: spinning really really fast.
Speaker 2: Okay, so the hypothesis goes, we saw the birth and
Speaker 2: the immediate collision of these forbidden baby neutron stars. Now
Speaker 2: we can finally lay out the full elegant superkillinova timeline
Speaker 2: that reconciles all the data.
Speaker 3: The theory is this sequential two part event, which is
Speaker 3: why it's hypothesized to be a superkillinova. A killinova embedded
Speaker 3: within and spurred by a supernova.
Speaker 2: Step one, a massive rapidly spinning star explodes codes in
Speaker 2: a core collapse supernova. This releases the initial bulk of
Speaker 2: energy and creates a huge debris cloud full of hydrogen.
Speaker 3: Step two, this massive explosion immediately gives birth to twin
Speaker 3: baby neutron stars, at least one of which must be
Speaker 3: subsolar based on the gravity weave data from S two
Speaker 3: five zero eight third K, and they are born orbiting
Speaker 3: each other right inside that expanding SUPERNOA debris Step three.
Speaker 2: Because they are born so close together, these newly formed
Speaker 2: neutron stars quickly spiral in and crash, creating a powerful
Speaker 2: Kilanova merger.
Speaker 3: And this is the event that released the strong detectable
Speaker 3: gravitational waves and that initial rush of heavy elements.
Speaker 2: So now we can use this timeline to explain the
Speaker 2: contradictory observations. Initially, for the first few days, the light
Speaker 2: was dominated by the Killanova merger.
Speaker 3: Right that merger churned out heavy neutron rich metals, which
Speaker 3: created that initial rapidly fading red glow that ZTF and
Speaker 3: the other telescope saw. The lanthanide curtain was briefly visible.
Speaker 2: But then the main event, that vast recloud from the
Speaker 2: initial larger supernova blasts from step one. It catches up
Speaker 2: and expands, and that cloud has hydrogen in it. It's
Speaker 2: still glowing and it's moving fast.
Speaker 3: And that debricloud expands and eventually obscures the underlying Killanova light.
Speaker 3: The Killanova is still there, glowing red, but now it's
Speaker 3: hidden behind the massive supernova ejecta. But that to Bricloud
Speaker 3: itself is energized and glowing, and this is what causes
Speaker 3: the light curve to lay to brighten again and turn
Speaker 3: blue and show those hydrogen spectra.
Speaker 2: So the blue color and the hydrogen signature, they're the
Speaker 2: signature of the larger, faster moving supernova debris washing out
Speaker 2: the underlying red Killanova flash.
Speaker 3: That's the theory. The event isn't just a simple merger.
Speaker 3: It's a merger immediately obscured by its own birth trauma.
Speaker 3: It's an event that collapses, splits, merges, and then explodes,
Speaker 3: all within a matter of days.
Speaker 2: That is why it looks like a killinova followed by
Speaker 2: a supernova, exactly.
Speaker 3: As Metzker put it. The only reliable way theorists can
Speaker 3: come up with to birth these subsolar neutron stars is
Speaker 3: during the collapse of a very rapidly spinning star. So
Speaker 3: if these forbidden stars pair up and merge, the resulting
Speaker 3: gravitational wave event would be immediately accompanied by a massive
Speaker 3: obscuring supernova rather than being seen as a bear killinova
Speaker 3: like G one seven zero eight intus teen. That dual
Speaker 3: explosion perfectly explains the dual light signature.
Speaker 2: It's an incredibly elegant solution to a massive cosmic contradiction.
Speaker 3: It is, but it's one that relies on the existence
Speaker 3: of stars we haven't actually confirmed anywhere else yea.
Speaker 2: And this theory is absolutely fascinating, But the research team
Speaker 2: is also quick to emphasize the uncertainty here. They stress
Speaker 2: that this is a tantalizing and interesting theory, but they
Speaker 2: don't have enough evidence yet to make firm, definitive claims.
Speaker 3: And that transparency is just crucial to the scientific process.
Speaker 3: This is the hypothesis that best fits the Messi data,
Speaker 3: but it all hinges on an unconfirmed stellar remnant that
Speaker 3: subsimilar mass neutron star.
Speaker 2: But the event is still eye opening.
Speaker 3: Oh absolutely, because it forces astronomers to expand them alludels
Speaker 3: of how massive stars in their lives. The very possibility
Speaker 3: of neutron stars existing in this subsolar mass range challenges
Speaker 3: some fundamental assumptions about stellar evolution.
Speaker 2: So if this model is correct, was there any part
Speaker 2: of the data that still didn't quite fit even with
Speaker 2: the super Killinova theory. No theory is perfect.
Speaker 3: That's a great point, and the fit is good, but
Speaker 3: the biggest challenge remains the sheer distance. At one point
Speaker 3: three billion light years eighteen twenty twenty twelve kilomeuse is
Speaker 3: much much farther away than GW one to seventy eight
Speaker 3: seventeen was that was only about one hundred and thirty
Speaker 3: million light.
Speaker 2: Years away, So the signal is just weaker, much weaker.
Speaker 3: Analyzing the precise mass ratios, the exact chemical composition from
Speaker 3: that distance is pushing the absolute limit of our current
Speaker 3: telescope technology. The figure details, you know, the subtle differences
Speaker 3: between a standard supernova and this hypothesized superkillinova ejecta. They're
Speaker 3: still murky. They really need many more examples to tighten
Speaker 3: up the parameters.
Speaker 2: Okay, so what does this all mean for the future
Speaker 2: of astronomy. The only way to test this to find
Speaker 2: more of them. But now we know that the simple
Speaker 2: killinova search criteria fast red and fading, that might be incomplete.
Speaker 3: It might be if the super Killinova model is right,
Speaker 3: future killinove might be easily mistaken for just mundane supernova.
Speaker 2: They could be hiding in plain sight.
Speaker 3: That's the key takeaway from Caswall and her team. We
Speaker 3: have to fundamentally change our search criteria. Future killinova events
Speaker 3: may not look like GW one seven oh eight seven
Speaker 3: to two. They might have this obscure dual signature, and
Speaker 3: they risk being mistaken for just another run of the
Speaker 3: mill hom supernova, especially by automated systems that aren't programmed
Speaker 3: to look for this kind of dual phase evolution.
Speaker 2: So we need next generation observational power we do.
Speaker 3: We need something that can catch that rapid initial flash
Speaker 3: and provide the deep spectral data to analyze the composition
Speaker 3: changes over time, even for extremely faint distant events.
Speaker 2: So let's detail some of the projects that will be
Speaker 2: essential for finding these things. These future observatories are designed
Speaker 2: for exactly this kind of challenge, right.
Speaker 3: We need both massive wide field survey telescopes to catch
Speaker 3: the initial flash and specialized instruments to look at the
Speaker 3: light that's obscured or at higher energies.
Speaker 2: Starting with the Vera Ruben Observatory. This is the project
Speaker 2: astronomers talk about constantly when it comes to transience. Why
Speaker 2: is it so vital here?
Speaker 3: Vera Reuben is a total game changer because of its
Speaker 3: sheer speed and its field of view. Its primary mission
Speaker 3: involves perpetually scanning the entire visible sky every few nights
Speaker 3: with this massive three point two gigapixel camera.
Speaker 2: So it'll just catch things faster.
Speaker 3: Much faster, much more reliably than even ZTF can. Now.
Speaker 3: It will just dramatically increase the probability of catching that
Speaker 3: crucial early red phase before the supernova component kicks in
Speaker 3: and washes everything out.
Speaker 2: So that addresses the speed challenge. But what about the
Speaker 2: need to peer through the obscuring debris, the problem that
Speaker 2: made eight twenty twenty five Elkoritz turn blue.
Speaker 3: For that, we turn to specific wavelength tools. Caltech is
Speaker 3: deploying some very specialized ground based tools for this, specifically
Speaker 3: the Deep Synoptic Array two thousand or DSA two thousand.
Speaker 3: It's a massive radio telescope array.
Speaker 2: And why are radio waves the ideal tool for penetrating
Speaker 2: that debris cloud?
Speaker 3: Radio waves have much longer wavelength than visible light. They're
Speaker 3: just much less susceptible to being scattered and absorbed by
Speaker 3: dense dust and gas clouds, including that huge hydrogen cloud
Speaker 3: from the initial supernova.
Speaker 2: Blast, so if the theory is correct.
Speaker 3: If the theory is correct, the underlying obscured killinover mergers
Speaker 3: should leave a characteristic radio signature as its own debris
Speaker 3: cloud expands, and DSA two thousand is designed to capture.
Speaker 2: Exactly that signal and then moving beyond Earth's atmosphere, we
Speaker 2: have space based assets like NASA's Nancy Roman Space Telescope.
Speaker 2: What's its advantage?
Speaker 3: Being in space? Roman will offer just unprecedented clarity and resolution,
Speaker 3: But critically it has a much wider field of view
Speaker 3: than Hubble, but with Hubble like image.
Speaker 2: Quality, so it can see more of the sky with
Speaker 2: the same precision, which.
Speaker 3: Is vital for distant events like eight twenty twenty five
Speaker 3: full planes. It can provide higher resolution like curve and
Speaker 3: spectra to analyze the chemical changes with way more precision,
Speaker 3: helping us determine if that late blue light truly is
Speaker 3: from hydrogen rich supernova ejecta.
Speaker 2: And finally, a focus on the ultraviolet spectrum with NASA's UVX,
Speaker 2: the Ultraviolet Explorer, which is led by Caltex Fiona Harrison.
Speaker 3: Why ultraviolet looking at UV is vital because the initial
Speaker 3: high energy component of these explosions often dominates in the
Speaker 3: ultraviolet the initial shock breakout the fastest moving material. It
Speaker 3: radiates intensely in.
Speaker 2: The UV band, so it gives you a look at
Speaker 2: the earliest moments, very earliest moments.
Speaker 3: If we're dealing with a dual phase explosion like this,
Speaker 3: the UV's signature might be very distinct and energetic. UVX
Speaker 3: would be perfectly positioned to capture those first moments before
Speaker 3: the debris clouds have fully expanded, giving us a clean
Speaker 3: look at the physics before all the optical confusion starts.
Speaker 2: So the path forward is clear. We need more sensitivity,
Speaker 2: more speed, and a multi wavelength capability to decode these transient,
Speaker 2: chaotic and just dual natured cosmic events. The universe is
Speaker 2: forcing us to build better tools because it insists on
Speaker 2: making things far more complicated than our models allowed.
Speaker 3: Indeed, this one event at twenty twenty five rolls have
Speaker 3: been so eye opening because it suggests a level of
Speaker 3: complexity and stellar death. We just hadn't mapped out the
Speaker 3: possibility of these subsolar mass neutron stars forming inside the
Speaker 3: collapsing core of a spinning star. It suggests the birth
Speaker 3: of stellar remnants is a far more chaotic process than
Speaker 3: we ever assumed.
Speaker 2: It fundamentally connects star death and dead star.
Speaker 3: Collision into a single terrifying element forging process.
Speaker 2: Yes, so the bottom line here is that the universe
Speaker 2: delivered a potential new cosmic category, the super killinova, the
Speaker 2: challenges that classic distinction, and it's all hinged on the
Speaker 2: detection of an impossibly small subsolar mass object that theorists
Speaker 2: thought could exist but had never actually seen.
Speaker 3: It forces us to reconsider the entire life cycle of
Speaker 3: the heaviest.
Speaker 2: Stars, which brings us to the bigger picture.
Speaker 3: Right, the relevance to us if the elements that make
Speaker 3: up our planet, you know, from the iron in our
Speaker 3: blood which is a supernova product, to the gold in
Speaker 3: our rings, which is a killin Ov product, if they're
Speaker 3: all created in these cataclysmic events, and if we're now
Speaker 3: discovering that these events can happen in these two step
Speaker 3: dual explosions, what other violent, unexpected pathways exist for creating
Speaker 3: the basic building blocks of life that we haven't even
Speaker 3: conceived of yet, a.
Speaker 2: Whole new branch of cosmic chemistry.
Speaker 3: It could be the fact that the smallest, most theoretically
Speaker 3: problematic neutron stars might be borne immediately within the largest
Speaker 3: stellar explosions. It suggests a fundamental and deeply interconnected violence
Speaker 3: between birth and death in the universe that we are
Speaker 3: only just beginning to map out. Perhaps the most profound
Speaker 3: chemical creation requires the fastest, most catastrophic destruction imaginable.
Speaker 2: School days La