WEBVTT 1 00:00:03.399 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:26.760 slumber under the night sky. 7 00:00:27.039 --> 00:00:30.079 Welcome to the deep Dive. Today, we're looking at an 8 00:00:30.079 --> 00:00:33.000 event that, well, it really pushes the limits of what 9 00:00:33.039 --> 00:00:36.159 we thought was possible. We're talking about an explosion that 10 00:00:36.200 --> 00:00:39.079 not only set a new cosmic speed record, but also 11 00:00:39.159 --> 00:00:42.320 showed us in real time how the universe forges some 12 00:00:42.399 --> 00:00:44.439 of its rarest and most precious elements. 13 00:00:44.679 --> 00:00:47.679 It's an incredible story. We're drawing mainly from a paper 14 00:00:47.719 --> 00:00:52.320 in the Astrophysical Journal that details this one event GRB 15 00:00:52.439 --> 00:00:55.520 two three zero three zero seven A. And it's a 16 00:00:55.560 --> 00:00:59.119 benchmark for two completely different fields of physics. Really, you 17 00:00:59.159 --> 00:01:02.320 have relative on one side and cosmic chemistry on the other. 18 00:01:02.439 --> 00:01:04.560 And let's just start with the number that caught everyone's attention. 19 00:01:04.640 --> 00:01:07.359 I mean, this thing was measured moving it ninety nine 20 00:01:07.400 --> 00:01:10.359 point eight percent the speed of light. 21 00:01:10.480 --> 00:01:12.760 It's just It's almost impossible to get your head around that. 22 00:01:12.760 --> 00:01:15.560 The margin is so incredibly small to accelerate actual matter 23 00:01:15.719 --> 00:01:18.239 that close to the ultimate speed limit. It just tells 24 00:01:18.239 --> 00:01:19.799 you there's sheer power we're dealing with. 25 00:01:19.920 --> 00:01:22.480 Right, and you, the listeners, should know. This wasn't some 26 00:01:22.560 --> 00:01:25.359 decades long project. The paper detailing this was led by 27 00:01:25.359 --> 00:01:27.760 a graduate student, Sarah de Lesi at the University of 28 00:01:27.760 --> 00:01:29.560 Alabama in Huntsville. 29 00:01:29.000 --> 00:01:33.599 Which is amazing, and her work highlights these two monumental facts. 30 00:01:34.200 --> 00:01:37.159 It's the fastest jet we've ever measured, and it's also 31 00:01:37.439 --> 00:01:41.480 the second brightest gamma ray burst or GRB seen in 32 00:01:41.519 --> 00:01:42.799 over fifty years of looking. 33 00:01:43.239 --> 00:01:46.400 Wow. Okay, so that combination of speed and brightness is 34 00:01:46.439 --> 00:01:50.040 what makes it so special exactly. It's an absolute outlier phenomenal. 35 00:01:50.319 --> 00:01:52.480 So here's how we're going to break this down. First, 36 00:01:52.480 --> 00:01:54.560 we have to talk about that speed, How on earth 37 00:01:54.560 --> 00:01:56.519 do you even measure that? We'll get into something called 38 00:01:56.560 --> 00:01:59.920 the Lorentz factor. Then we'll look at the people and 39 00:02:00.120 --> 00:02:03.120 the technology behind the discovery. This wasn't an accident. It 40 00:02:03.200 --> 00:02:06.200 was a result of a huge, coordinated effort, a very 41 00:02:06.280 --> 00:02:10.240 rapid one, and finally the big payoff. How this record 42 00:02:10.240 --> 00:02:13.319 breaking burst gave us the smoking gun for where heavy 43 00:02:13.319 --> 00:02:17.919 elements we're talking gold, platinum, and one in particular, tilurium, actually. 44 00:02:17.639 --> 00:02:19.599 Come from the cosmic kitchen, as they call. 45 00:02:19.520 --> 00:02:21.960 It, the cosmic kitchen. Okay, let's start with the basics. 46 00:02:22.120 --> 00:02:24.680 What exactly is a gamma ray burst. We know they 47 00:02:24.680 --> 00:02:27.400 are the most powerful explosions out there, but what makes 48 00:02:27.439 --> 00:02:30.120 GRB two three zero three zero seven a stand out 49 00:02:30.120 --> 00:02:30.639 from the rest? 50 00:02:30.960 --> 00:02:32.840 Well, the first thing to remember is that a GRB 51 00:02:33.080 --> 00:02:35.840 isn't like a bomb going off in all directions. It's 52 00:02:35.879 --> 00:02:39.080 a highly focused beam of energy, a jet like. 53 00:02:39.039 --> 00:02:40.680 A cosmic laser beam sort of. 54 00:02:40.800 --> 00:02:44.919 Yeah, a jet of matter and radiation moving incredibly fast. 55 00:02:45.120 --> 00:02:47.960 And this one two three zero three zero seven A 56 00:02:48.240 --> 00:02:52.199 is what scientists call ultra relativistic, which is just a 57 00:02:52.240 --> 00:02:54.520 fancy way of saying its speed is so extreme that 58 00:02:54.599 --> 00:02:57.560 you have to use Einstein's theory of special relativity to 59 00:02:57.599 --> 00:02:58.960 even begin to describe it. 60 00:02:59.000 --> 00:03:01.759 And that's where that ninety nine point nine nine eight 61 00:03:01.800 --> 00:03:04.280 percent the speed of light figure comes from. That's not 62 00:03:04.400 --> 00:03:07.400 just a mind boggling number. It implies some truly insane 63 00:03:07.439 --> 00:03:08.879 physics are happening at the source. 64 00:03:09.000 --> 00:03:12.319 It really does, and to measer that tiny difference between 65 00:03:12.319 --> 00:03:14.319 the jet speed and the actual speed of light, which 66 00:03:14.360 --> 00:03:16.479 is about one hundred and eighty six thousand miles per second. 67 00:03:17.000 --> 00:03:19.199 You need a special tool. You can't just subtract one 68 00:03:19.199 --> 00:03:19.639 from the other. 69 00:03:19.680 --> 00:03:20.759 Okay, so what is that tool. 70 00:03:21.000 --> 00:03:23.800 It's a number called the Lorentz factor, often just abbreviated 71 00:03:23.800 --> 00:03:26.919 as LF. It's a way of quantifying the effects of 72 00:03:26.960 --> 00:03:29.719 moving that fast. It tells you how much an object's 73 00:03:29.800 --> 00:03:32.280 energy is boosted because it's approaching the speed of light. 74 00:03:32.479 --> 00:03:34.919 So it's not a direct speed measurement, more like a 75 00:03:34.919 --> 00:03:37.439 measurement of the relativistic effects of that speed. 76 00:03:37.599 --> 00:03:41.680 Precisely, and in the context of this GRB, the Lorentz 77 00:03:41.759 --> 00:03:44.520 factor is what we use to measure the velocity of 78 00:03:44.560 --> 00:03:48.840 that that fireball of ejected material. A higher Lorentz factor 79 00:03:48.879 --> 00:03:50.719 means you're closer to the speed of light. 80 00:03:50.800 --> 00:03:53.719 And astronomers can calculate this how I mean, they're obviously 81 00:03:53.719 --> 00:03:55.159 not there with a radar gun. 82 00:03:55.319 --> 00:03:56.039 No, they're not. 83 00:03:56.280 --> 00:03:59.759 It all comes down to a phenomenon called relativistic beaming 84 00:04:00.120 --> 00:04:01.159 or Doppler boosting. 85 00:04:01.479 --> 00:04:04.759 Oh okay, this is why they appear so incredibly bright 86 00:04:04.800 --> 00:04:07.199 to us, even from billions of light years away. 87 00:04:07.319 --> 00:04:07.680 That's it. 88 00:04:07.759 --> 00:04:11.199 Exactly, when the jet is moving towards you at these speeds, 89 00:04:11.319 --> 00:04:14.039 all the light it's emitting gets focused into this very 90 00:04:14.199 --> 00:04:17.920 very narrow cone pointed right at you. The Lorentz factor 91 00:04:18.000 --> 00:04:20.720 quantifies how intense that focusing effect is. It makes the 92 00:04:20.800 --> 00:04:23.600 light appear way brighter and shifts it to higher energies 93 00:04:23.639 --> 00:04:24.519 than it would otherwise. 94 00:04:24.639 --> 00:04:28.000 To a higher Lorentz factor means a more focused, brighter beam. 95 00:04:27.879 --> 00:04:29.680 Right, And that's a huge clue. 96 00:04:29.839 --> 00:04:34.160 To actually get the number, astronomers have to watch the afterglow. 97 00:04:33.800 --> 00:04:37.639 The afterglow being the light produced after the initial flash 98 00:04:37.720 --> 00:04:39.959 as the jet material slams into all the gas and 99 00:04:40.040 --> 00:04:41.600 dust that's just sitting around in space. 100 00:04:41.759 --> 00:04:45.639 Yes, and as that jet plows into the interstellar medium, 101 00:04:45.839 --> 00:04:48.680 it starts to slow down, and as it slows, that 102 00:04:48.800 --> 00:04:52.040 beaming effect gets weaker. The light curve, the way the 103 00:04:52.079 --> 00:04:55.519 brightness fades over time, changes in a very specific way 104 00:04:55.920 --> 00:04:58.680 that depends directly on that initial Lorentz factor. 105 00:04:58.839 --> 00:05:00.360 So they're modeling the decay the light. 106 00:05:00.480 --> 00:05:02.959 They're modeling the decay looking at the spectrum how the 107 00:05:03.079 --> 00:05:06.839 energy of the light changes. They look for specific signatures 108 00:05:06.879 --> 00:05:10.000 in the radiation and by comparing what they see to 109 00:05:10.120 --> 00:05:14.279 these really sophisticated computer models, they can work backward and 110 00:05:14.279 --> 00:05:16.199 figure out what the initial speed must have been. 111 00:05:16.560 --> 00:05:19.199 It's like seeing the skid marks and calculating how fast 112 00:05:19.240 --> 00:05:21.040 the car was going before it hit the brakes. 113 00:05:21.120 --> 00:05:23.160 That's a great analogy, and that's how they came up 114 00:05:23.199 --> 00:05:25.800 with the Lorentz factor for GRB two three oh three 115 00:05:25.920 --> 00:05:26.639 user seven A. 116 00:05:26.920 --> 00:05:29.399 Okay, so let's put that number in perspective. What did 117 00:05:29.399 --> 00:05:31.720 we think was fast for a GRB before this? 118 00:05:32.079 --> 00:05:35.360 Well, based on you know, decades of observations, a typical 119 00:05:35.360 --> 00:05:38.319 GRB might have a Lorentz factor of maybe a few hundreds. 120 00:05:38.360 --> 00:05:39.759 A three hundred and three. 121 00:05:39.680 --> 00:05:43.000 Hundred is already something like ninety nine point nine nine 122 00:05:43.120 --> 00:05:46.319 five percent the speed of light, right, already incredibly fast. 123 00:05:46.360 --> 00:05:50.439 Oh yeah, mind moggelingly fast. We considered anything pushing up 124 00:05:50.480 --> 00:05:53.399 towards the Lorentz factor of one thousand to be, you know, 125 00:05:53.480 --> 00:05:56.000 exceptionally rare and energetic. That was sort of the upper 126 00:05:56.040 --> 00:05:56.879 limit of what we've seen. 127 00:05:57.000 --> 00:05:59.040 But this one wasn't hunt thousand nooks. 128 00:05:59.079 --> 00:06:00.800 What this one was measured sixteen. 129 00:06:00.519 --> 00:06:04.160 Hundred, Wow, sixteen hundred. That's not just breaking the record, 130 00:06:04.199 --> 00:06:05.560 it's it's shattering it. 131 00:06:05.560 --> 00:06:09.000 It completely shatters it. It's a sixty percent jump over 132 00:06:09.040 --> 00:06:11.920 the previous highest confirmed measurement. There's a great quote from 133 00:06:11.920 --> 00:06:14.040 doctor Peter Veyers, one of the authors, who just says, 134 00:06:14.319 --> 00:06:16.560 the Lorentz factor is the measure of speed of the 135 00:06:16.639 --> 00:06:19.800 jet here, and sixteen hundred is the highest we ever measured. 136 00:06:20.000 --> 00:06:22.480 It's just a plain statement of a new reality. 137 00:06:22.600 --> 00:06:25.800 So that number sixteen hundred means the matter in that 138 00:06:25.920 --> 00:06:28.399 jet was moving within just thirty parts per million of 139 00:06:28.439 --> 00:06:29.040 the speed of life. 140 00:06:29.160 --> 00:06:32.160 Yes, for you listening, just try to imagine the physics 141 00:06:32.199 --> 00:06:34.839 involved there. What kind of cosmic engine can take a 142 00:06:34.959 --> 00:06:37.959 huge amount of matter and accelerate it so perfectly, so 143 00:06:38.120 --> 00:06:42.120 efficiently that it gets that close to the absolute, unbreakable 144 00:06:42.160 --> 00:06:43.040 speed limit. 145 00:06:42.800 --> 00:06:43.439 Of the universe. 146 00:06:43.519 --> 00:06:46.680 It really forces you to ask new questions. Does this 147 00:06:46.839 --> 00:06:50.160 mean these explosions are even more powerful than we thought? 148 00:06:50.519 --> 00:06:53.480 Or is there some some new mechanism at play that 149 00:06:53.560 --> 00:06:56.120 makes the jet acceleration super efficient? 150 00:06:56.240 --> 00:06:59.360 And that's the big theoretical question this whole discovery raises, 151 00:06:59.639 --> 00:07:03.360 and of sixteen hundred suggests that the central engine whatever 152 00:07:03.439 --> 00:07:07.079 created this jet, converted its energy into outward motion with 153 00:07:07.199 --> 00:07:08.920 almost perfect efficiency. 154 00:07:08.959 --> 00:07:10.360 There was very little waste. 155 00:07:10.480 --> 00:07:12.120 So what could do that? What kind of engine are 156 00:07:12.120 --> 00:07:12.720 we talking about? 157 00:07:12.839 --> 00:07:16.240 The leading idea is that it has to involve incredibly 158 00:07:16.319 --> 00:07:20.519 powerful and very specifically ordered magnetic fields. Okay, so when 159 00:07:20.560 --> 00:07:23.240 you have two neutron stars merging, which we now know 160 00:07:23.319 --> 00:07:26.759 is what caused this, they briefly form this single super 161 00:07:26.839 --> 00:07:30.639 dense object that's spinning furiously, and it has a magnetic 162 00:07:30.639 --> 00:07:31.560 field that's just. 163 00:07:32.360 --> 00:07:35.199 Astronomical stronger than anything we can imagine. 164 00:07:34.759 --> 00:07:37.600 Thousands of times stronger than even a magnetars. And as 165 00:07:37.680 --> 00:07:40.800 this object spins, it winds up these magnetic field lines 166 00:07:40.839 --> 00:07:44.360 into a kind of twisted tower. That magnetic tower acts 167 00:07:44.360 --> 00:07:46.959 like a nozzle, a channel that funnels all the energy 168 00:07:46.959 --> 00:07:49.439 and plasma out into two perfectly straight jets. 169 00:07:49.720 --> 00:07:53.079 So it's not just a messy explosion. It's a finely 170 00:07:53.160 --> 00:07:55.000 tuned cosmic canon, a. 171 00:07:55.000 --> 00:07:59.879 Perfectly engineered cosmic syringe. Really, and a Lorentz factor of 172 00:08:00.319 --> 00:08:03.600 sixteen hundred tells us that for this specific event, that 173 00:08:03.639 --> 00:08:07.800 magnetic structure was almost flawless. It extracted energy from the 174 00:08:07.839 --> 00:08:11.959 merger and shot it into space with almost no loss. 175 00:08:12.079 --> 00:08:16.079 Incredible, and that perfect violent efficiency is what leads us 176 00:08:16.120 --> 00:08:18.319 to how it was even discovered in the first place. 177 00:08:18.120 --> 00:08:20.480 It does, which brings us to the logistics. I mean, 178 00:08:20.839 --> 00:08:23.199 an event this fast and this bright is over in 179 00:08:23.240 --> 00:08:25.279 a flash, you have to be ready, you have to 180 00:08:25.279 --> 00:08:26.399 be watching all the time. 181 00:08:26.480 --> 00:08:28.879 And the instrument that was watching was the Fermi Gamma 182 00:08:28.920 --> 00:08:32.200 Ray Burst Monitor or GBM. It's on NASA's Fermi Gamma 183 00:08:32.279 --> 00:08:34.279 Ray Space Telescope, which has been up there since two 184 00:08:34.279 --> 00:08:37.159 thousand and eight, basically staring at the sky waiting for 185 00:08:37.200 --> 00:08:37.799 these flashes. 186 00:08:37.799 --> 00:08:41.279 It's the universe's ultimate early warning system. The GBM itself 187 00:08:41.320 --> 00:08:44.480 has these fourteen detectors positioned all around the satellite, so 188 00:08:44.519 --> 00:08:47.120 it's always watching the whole sky at once. And the 189 00:08:47.159 --> 00:08:50.159 team that runs it is a huge international collaboration. 190 00:08:49.919 --> 00:08:53.320 Right with NASA, the Max Planck Institute in Germany, and 191 00:08:53.399 --> 00:08:56.759 crucially the operations hub at the University of Alabama in Huntsville. 192 00:08:56.840 --> 00:08:59.960 And that's where Sarah de Lesi, the lead author, comes 193 00:09:00.120 --> 00:09:03.440 into the story because at the exact moment this burst 194 00:09:03.480 --> 00:09:04.159 went off. 195 00:09:04.279 --> 00:09:05.879 She was on duty. 196 00:09:06.080 --> 00:09:08.120 What was her role, I mean, what does that actually 197 00:09:08.120 --> 00:09:09.000 involve in the moment. 198 00:09:09.320 --> 00:09:12.240 Her official title was the burst Advocate, and that's a 199 00:09:13.159 --> 00:09:15.679 very high pressure on call position. 200 00:09:15.919 --> 00:09:18.039 So she's the first human to analyze the data. 201 00:09:18.200 --> 00:09:21.480 Essentially, yes, the satellite detects a burst of gamma rays 202 00:09:21.519 --> 00:09:24.279 and automatically sends down an alert. The computer does a 203 00:09:24.320 --> 00:09:27.639 quick rough analysis, but it's the burst advocate who has 204 00:09:27.679 --> 00:09:31.080 to immediately jump on the raw data and figure out, Okay, 205 00:09:31.240 --> 00:09:32.639 what are we really looking at here? 206 00:09:32.759 --> 00:09:34.320 Is this real? Is it important? 207 00:09:34.360 --> 00:09:36.840 And the clock is ticking. You've got telescopes all over 208 00:09:36.840 --> 00:09:38.600 the world that need to be pointed at this thing 209 00:09:38.720 --> 00:09:41.120 right away if it's going to be studied in seconds. 210 00:09:41.399 --> 00:09:44.440 She has to figure out three things almost instantly. One 211 00:09:44.600 --> 00:09:47.960 where is it the localization so other telescopes know where 212 00:09:47.960 --> 00:09:50.000 to look. Two what kind of burst is it? The 213 00:09:50.039 --> 00:09:53.320 initial classification? And three how bright is it? And that 214 00:09:53.440 --> 00:09:55.759 last one is what set off all the alarm bells. 215 00:09:56.080 --> 00:09:59.799 Right, She's quoted in the source material saying she knew 216 00:09:59.840 --> 00:10:03.080 the this was an extraordinarily bright event, perhaps the second 217 00:10:03.120 --> 00:10:07.080 or third brightest GRB. Ever, how do you know that? 218 00:10:07.320 --> 00:10:09.000 In a matter of moments? 219 00:10:09.240 --> 00:10:12.120 It comes down to the photon count. The data packet 220 00:10:12.120 --> 00:10:14.840 from the satellite tells you how many gamma ray photons 221 00:10:14.919 --> 00:10:18.000 hit the detectors per second, and the number for this 222 00:10:18.120 --> 00:10:22.159 event was just off the charts. Her training and experience 223 00:10:22.200 --> 00:10:25.120 told her immediately that this wasn't a run of the millburst. 224 00:10:25.519 --> 00:10:27.360 This was something historic. 225 00:10:27.120 --> 00:10:31.039 And that quick expert decision is the lynchpin for everything 226 00:10:31.039 --> 00:10:31.559 that followed. 227 00:10:31.639 --> 00:10:34.799 Absolutely because she and the team could classify it as 228 00:10:34.799 --> 00:10:38.480 a major, major event so quickly they triggered a global alert. 229 00:10:38.759 --> 00:10:41.399 They told everyone with a powerful telescope, you need to 230 00:10:41.480 --> 00:10:44.399 drop what you're doing and point it here right now. 231 00:10:44.200 --> 00:10:47.559 And that includes getting a request in for time on 232 00:10:47.600 --> 00:10:50.759 the biggest instruments we have, like the James Webspace telescope. 233 00:10:51.080 --> 00:10:55.039 Exactly without that lightning fast analysis from the first advocate, 234 00:10:55.360 --> 00:10:58.240 the window to observe the actor glow would have closed. 235 00:10:58.639 --> 00:11:01.000 We would have seen the flash of GMS, but we 236 00:11:01.000 --> 00:11:04.399 would have missed the real prize, the killinova that followed 237 00:11:04.639 --> 00:11:07.720 the entire story of element creation would have been lost. 238 00:11:08.000 --> 00:11:10.639 It's amazing that it all inges on that one moment 239 00:11:10.799 --> 00:11:13.600 of human expertise. And this is the same team I 240 00:11:13.600 --> 00:11:17.240 should point out that also found the brightest GRB ever 241 00:11:17.279 --> 00:11:18.799 seen just a little while earlier. 242 00:11:18.919 --> 00:11:20.240 They're on an incredible run. 243 00:11:20.279 --> 00:11:22.799 It just shows that even with all our automated systems, 244 00:11:23.120 --> 00:11:26.240 you still need that sharp trained scientist in the loop 245 00:11:26.320 --> 00:11:30.159 to connect the dots and realize you're seeing something truly revolutionary. 246 00:11:30.440 --> 00:11:33.000 Okay, so let's pivot from the detection to what they found. 247 00:11:33.360 --> 00:11:35.759 The speed was the headline, the brightness got their attention, 248 00:11:36.080 --> 00:11:39.879 but the real scientific gold mine was in confirming what 249 00:11:40.039 --> 00:11:43.360 kind of explosion this actually was. And that brings us, 250 00:11:43.399 --> 00:11:45.159 as you said, to the killinova. Right. 251 00:11:45.600 --> 00:11:48.960 The kilanova is the key piece of evidence. The GRB itself, 252 00:11:49.000 --> 00:11:53.120 that's the initial focused beam of light. It's incredibly bright, 253 00:11:53.200 --> 00:11:56.320 but it's over quickly. The kilanova is something different. It's 254 00:11:56.360 --> 00:11:59.759 the faint, fading glow from the cloud of radioactive debris 255 00:11:59.759 --> 00:12:01.600 thrown out by the explosion itself. 256 00:12:01.639 --> 00:12:04.080 So if the GOLB is the muzzle flash of the cannon, 257 00:12:04.519 --> 00:12:07.679 the killing nova is the lingering cloud of smoke. 258 00:12:07.960 --> 00:12:10.000 That's a perfect way to put it. And it's so 259 00:12:10.159 --> 00:12:14.519 important because a killanova is the unique, unambiguous signature of 260 00:12:14.600 --> 00:12:18.519 two super dense objects colliding, either two neutron stars or 261 00:12:18.559 --> 00:12:19.519 a neutron star in. 262 00:12:19.480 --> 00:12:20.000 A black hole. 263 00:12:20.080 --> 00:12:22.360 And why is it signature so unique? What's in that 264 00:12:22.440 --> 00:12:23.120 smoke cloud? 265 00:12:23.519 --> 00:12:26.279 Heavy elements, newly created heavy elements. This is where we 266 00:12:26.320 --> 00:12:28.159 get to that great analogy from Sarah to Lessi in 267 00:12:28.200 --> 00:12:30.720 the paper where she says these mergers act as a 268 00:12:30.799 --> 00:12:32.919 cosmic kitchen for heavy element. 269 00:12:32.679 --> 00:12:35.279 The cosmic kitchen. I love that. Yeah, let's break down 270 00:12:35.320 --> 00:12:38.480 that recipe. Why is a neutron star merger the perfect 271 00:12:38.480 --> 00:12:41.159 place to cook up things like gold and platinum when 272 00:12:41.200 --> 00:12:43.679 a regular star exploding can't do it? 273 00:12:43.679 --> 00:12:48.440 It all comes down to one crucial ingredient, neutrons, a ridiculous, 274 00:12:48.559 --> 00:12:51.360 unimaginable density of free neutrons. 275 00:12:51.080 --> 00:12:53.600 Because the neutron star is basically just a giant ball. 276 00:12:53.440 --> 00:12:54.399 Of them exactly. 277 00:12:54.600 --> 00:12:58.200 It's what's left after a star has collapsed and gravity 278 00:12:58.279 --> 00:13:01.039 has crushed all the atoms so tightly that the protons 279 00:13:01.039 --> 00:13:04.960 and electrons have merged to form neutrons. A single tea 280 00:13:04.960 --> 00:13:08.279 spoon of that stuff weighs billions of tons. Okay, So 281 00:13:08.399 --> 00:13:11.720 when two of those slam into each other, huge amounts 282 00:13:11.720 --> 00:13:14.559 of this pure neutron matter get ripped off and flung 283 00:13:14.600 --> 00:13:15.879 out into space, and. 284 00:13:15.879 --> 00:13:18.960 That cloud of ejected neutrons is where the magic happens. 285 00:13:19.039 --> 00:13:22.159 That's where the alchemy happens. For a very brief moment, 286 00:13:22.279 --> 00:13:25.960 you have this cloud that is both incredibly hot and 287 00:13:26.159 --> 00:13:29.960 packed with more free neutrons than anywhere else in the universe. 288 00:13:30.759 --> 00:13:33.240 And in those conditions you get something called the rapid 289 00:13:33.320 --> 00:13:34.919 neutron capture process, the. 290 00:13:35.000 --> 00:13:37.720 R process, rapid being the keyword there, the keyword. 291 00:13:38.039 --> 00:13:41.440 It means that existing atomic nuclei like iron or just 292 00:13:41.600 --> 00:13:45.399 bombarded with this flood of neutrons. They absorb neutrons faster, 293 00:13:45.679 --> 00:13:48.639 much faster than they have time to radioactively decay, So 294 00:13:48.679 --> 00:13:51.240 they just get heavier and heavier and heavier, climbing up 295 00:13:51.279 --> 00:13:52.919 the periodic table in a split second. 296 00:13:52.919 --> 00:13:55.039 So it's a high speed nuclear assembly line, the. 297 00:13:55.080 --> 00:13:57.440 Ultimate assembly line. It's the only way we know of 298 00:13:57.480 --> 00:14:00.320 to produce most of the elements heavier than iron. So 299 00:14:00.559 --> 00:14:04.399 every gold wedding band, every platinum catalyst in a car, 300 00:14:05.240 --> 00:14:08.039 it was all forged in a cataclysm like this one. 301 00:14:08.120 --> 00:14:11.519 That is just incredible to think about it. So we 302 00:14:11.559 --> 00:14:14.000 have this theory. The GRB goes off, we see the 303 00:14:14.080 --> 00:14:17.360 Kilanova and we say, aha, the our process is happening 304 00:14:17.360 --> 00:14:20.240 in there. But this observation, when a step further, didn't 305 00:14:20.240 --> 00:14:23.279 it they actually saw one of the elements being made. 306 00:14:23.360 --> 00:14:26.159 They did, and this is the monumental part of the discovery. 307 00:14:26.200 --> 00:14:30.600 They found the specific spectral fingerprint of the heavy element tulurium. 308 00:14:30.720 --> 00:14:33.279 Telurium. Why is that one so important? We always hear 309 00:14:33.279 --> 00:14:34.840 about gold and platinum. 310 00:14:34.879 --> 00:14:37.080 Well, golden platinum are definitely being made in there, but 311 00:14:37.120 --> 00:14:40.120 they are incredibly difficult to see. Their atomic structures are 312 00:14:40.159 --> 00:14:43.279 so complex that they just create a sort of a messy, 313 00:14:43.639 --> 00:14:47.320 blended out spectrum in the Kilanova's light. It's hard to 314 00:14:47.320 --> 00:14:48.480 pick out a clear signal. 315 00:14:48.720 --> 00:14:51.159 They're spectroscopically noisy, you could say. 316 00:14:51.080 --> 00:14:51.799 Varying razy. 317 00:14:52.200 --> 00:14:56.279 Tilurium, however, has a much cleaner, more distinct signature. It 318 00:14:56.320 --> 00:14:59.960 produces very clear absorption lines in the near infrared part 319 00:15:00.000 --> 00:15:01.279 part of the spectrum, and. 320 00:15:01.320 --> 00:15:05.879 Which telescope is the undisputed king of near infrared astronomy. 321 00:15:05.559 --> 00:15:08.279 The James web Space telescope. So the follow up team 322 00:15:08.279 --> 00:15:11.120 in Europe knew exactly what to do. They pointed Web 323 00:15:11.159 --> 00:15:12.840 at the fading law of this event, looked at the 324 00:15:12.919 --> 00:15:16.120 near infrared light, and there it was not an inference, 325 00:15:16.240 --> 00:15:19.559 not a guess from a model, but a clear, direct, 326 00:15:19.840 --> 00:15:22.279 unmistakable signature of tellurium. 327 00:15:22.679 --> 00:15:23.759 That's the smoking gun. 328 00:15:23.799 --> 00:15:24.879 That is the smoking gun. 329 00:15:24.960 --> 00:15:28.120 It's the first time we've ever directly identified a specific 330 00:15:28.480 --> 00:15:31.799 r process element being created in the aftermath of a GRB, So. 331 00:15:31.799 --> 00:15:34.440 The whole chain of events is complete. The record breaking 332 00:15:34.480 --> 00:15:37.159 speed got their attention. The rapid follow up. Let them 333 00:15:37.159 --> 00:15:40.440 watch the aftermath and the power of JWST Let them 334 00:15:40.480 --> 00:15:44.559 look inside that aftermath and confirm that this cosmic kitchen 335 00:15:44.799 --> 00:15:48.080 was in fact cooking up tellurium, an element we use 336 00:15:48.159 --> 00:15:50.240 right here on Earth in things like solar panels. 337 00:15:50.399 --> 00:15:54.120 It's a perfect connection from the most extreme relativistic physics 338 00:15:54.159 --> 00:15:56.720 in the universe straight down to the chemistry that enables 339 00:15:56.720 --> 00:15:59.840 our technology. A truly remarkable piece of detective work. 340 00:16:00.200 --> 00:16:02.320 So where does the field go from here? I mean, 341 00:16:02.320 --> 00:16:04.840 this discovery was so successful it seems like it lays 342 00:16:04.879 --> 00:16:07.639 out a clear path forward for researchers like Sarah de Lassie. 343 00:16:07.759 --> 00:16:10.480 It does, but it also creates a new puzzle. The 344 00:16:10.519 --> 00:16:13.879 big challenge now is that GRB two three zero three 345 00:16:14.000 --> 00:16:17.039 oh seven aa kind of breaks the old rules we 346 00:16:17.120 --> 00:16:20.639 use for classification. So historically, the rule of thumb was 347 00:16:20.679 --> 00:16:24.320 pretty simple. If a GRB lasted for more than two seconds, 348 00:16:24.360 --> 00:16:26.720 it was a long burst, and we assumed it came 349 00:16:26.759 --> 00:16:29.679 from a massive star collapsing. If it was less than 350 00:16:29.720 --> 00:16:32.279 two seconds a short burst, we assumed it was a 351 00:16:32.320 --> 00:16:34.320 merger of two compact objects. 352 00:16:34.399 --> 00:16:36.200 Okay, that seems straightforward enough. 353 00:16:36.200 --> 00:16:38.360 But this one two three oh three oh seven A 354 00:16:38.639 --> 00:16:39.360 was a long burst. 355 00:16:39.399 --> 00:16:41.039 It lasted for quite a while. 356 00:16:41.159 --> 00:16:44.559 Yet the Kilanov approved without any doubt that its source 357 00:16:44.720 --> 00:16:45.279 was a merger. 358 00:16:45.919 --> 00:16:47.840 So it was a long burst from a merger event. 359 00:16:48.080 --> 00:16:48.879 It breaks the mold. 360 00:16:48.919 --> 00:16:50.679 It completely breaks a mold, And this is where the 361 00:16:50.679 --> 00:16:53.600 cutting edge research is now. The biggest goal in what 362 00:16:53.639 --> 00:16:56.320 de Lessie is working on is finding more of these weird, 363 00:16:56.399 --> 00:16:58.639 long duration merger events. 364 00:16:58.440 --> 00:16:59.919 To see if this is a one off freak event 365 00:17:00.120 --> 00:17:02.200 enter a whole new class of explosion we didn't know 366 00:17:02.240 --> 00:17:03.600 about exactly. 367 00:17:03.879 --> 00:17:06.519 If we can find more, it helps us understand the 368 00:17:06.599 --> 00:17:10.319 different ways neutron star mergers can play out. Maybe sometimes 369 00:17:10.319 --> 00:17:13.200 they collapse into a black hole instantly creating a short burst, 370 00:17:13.480 --> 00:17:16.440 but maybe other times, like this one, they form a 371 00:17:16.480 --> 00:17:20.119 temporary hyper massive neutron star that survives for a few 372 00:17:20.160 --> 00:17:23.000 extra seconds, pumping out a longer lasting jet. 373 00:17:23.079 --> 00:17:25.599 But the big bottleneck is still there, isn't it. To 374 00:17:25.640 --> 00:17:28.200 be sure it's a merger, you have to catch that kilnova, 375 00:17:28.519 --> 00:17:31.920 which means you need that massive, time sensitive follow up 376 00:17:31.960 --> 00:17:34.039 campaign with telescopes like web. 377 00:17:34.359 --> 00:17:37.160 It is the bottleneck. It's expensive and you have to 378 00:17:37.200 --> 00:17:40.079 be incredibly fast. We got lucky with two three zero 379 00:17:40.079 --> 00:17:42.119 three oh seven A because it was so bright we 380 00:17:42.200 --> 00:17:44.559 knew it was special. But what about a fainter one. 381 00:17:44.599 --> 00:17:47.799 We can't point web at every single long GRB just 382 00:17:47.880 --> 00:17:48.960 on a hunch, so. 383 00:17:48.920 --> 00:17:50.400 We need a wait to know what's a merger before 384 00:17:50.440 --> 00:17:51.720 the Killinova even appears. 385 00:17:51.839 --> 00:17:55.079 That's the holy grail, and that's de Leesi's specific research goal. 386 00:17:55.400 --> 00:17:58.519 She's trying to find a subtle signature, a hidden clue 387 00:17:58.640 --> 00:18:01.440 in the prompt emission, the shall flash of gamma rays 388 00:18:01.480 --> 00:18:02.799 itself that screams. 389 00:18:02.440 --> 00:18:04.880 Mergers, kind of secret handshake and the light curve. What 390 00:18:04.920 --> 00:18:05.599 are they looking for. 391 00:18:05.799 --> 00:18:08.880 They're digging through the data looking for tiny differences between 392 00:18:08.920 --> 00:18:12.319 the jets from mergers and the jets from collapsing stars. 393 00:18:13.480 --> 00:18:16.039 Maybe the jet from a merger has a slightly different 394 00:18:16.079 --> 00:18:20.079 temperature or a slightly different energy spectrum because it's blasting 395 00:18:20.119 --> 00:18:22.000 out into a cleaner environment. 396 00:18:21.799 --> 00:18:24.440 Whereas the jet from a collapsing star has to punch 397 00:18:24.480 --> 00:18:26.839 its way out of the star's outer layers. 398 00:18:26.440 --> 00:18:28.720 First, right, and that might leave a mark on the 399 00:18:28.759 --> 00:18:31.920 gamma ray signal. They're looking for subtle wiggles in the 400 00:18:32.000 --> 00:18:35.599 light curve or changes in the spectral properties. It's a 401 00:18:35.680 --> 00:18:39.960