1 00:00:01,840 --> 00:00:07,600 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey brain Stuff, 2 00:00:07,640 --> 00:00:14,280 Speaker 1: Lauren Vogelbomb. Here humans are born, then we grow and die. 3 00:00:14,760 --> 00:00:17,880 Speaker 1: Our life cycles are basically the same as those of 4 00:00:17,960 --> 00:00:21,840 Speaker 1: the massive stars twinkling in the night sky. If we 5 00:00:22,079 --> 00:00:24,400 Speaker 1: exploded in a blaze of glory at the end of 6 00:00:24,400 --> 00:00:29,400 Speaker 1: our time when the cosmosis, most colossal stars go out 7 00:00:29,440 --> 00:00:33,120 Speaker 1: with a bang. The immense interstellar explosion is known as 8 00:00:33,159 --> 00:00:38,040 Speaker 1: a supernova, while smaller stars simply fizzle out. The death 9 00:00:38,080 --> 00:00:42,320 Speaker 1: of an astronomical heavyweight is a showstopper. It spent its 10 00:00:42,400 --> 00:00:46,080 Speaker 1: life cannibalizing its own inerds for fuel and sometimes the 11 00:00:46,120 --> 00:00:49,560 Speaker 1: intererds of a solar neighbor. When there is nothing left 12 00:00:49,600 --> 00:00:52,159 Speaker 1: for it to consume, it collapses in on itself and 13 00:00:52,280 --> 00:00:56,040 Speaker 1: then explodes outward and a depth knell that outshines other 14 00:00:56,160 --> 00:01:00,520 Speaker 1: huge stars and sometimes entire galaxies for days, weeks, or 15 00:01:00,640 --> 00:01:04,040 Speaker 1: even months. Some are so bright that they can be 16 00:01:04,120 --> 00:01:09,839 Speaker 1: seen with a simple set of binoculars. A supernova should 17 00:01:09,920 --> 00:01:13,080 Speaker 1: statistically detonate once every fifty years or so in a 18 00:01:13,200 --> 00:01:17,360 Speaker 1: galaxy the size of our Milky Way, So how do 19 00:01:17,400 --> 00:01:20,759 Speaker 1: you spot one? Identifying a new point of light as 20 00:01:20,800 --> 00:01:23,920 Speaker 1: a supernova as opposed to a high flying aircraft or 21 00:01:23,959 --> 00:01:27,680 Speaker 1: a comet, may be easier than you think. The stars 22 00:01:27,760 --> 00:01:31,000 Speaker 1: about to go supernova change color from red to blue 23 00:01:31,200 --> 00:01:36,160 Speaker 1: due to their increasing temperatures, and supernova maintain some blue 24 00:01:36,160 --> 00:01:39,080 Speaker 1: color due to the Doppler effect. The light from their 25 00:01:39,120 --> 00:01:44,200 Speaker 1: explosions moves towards us so fast that it appears blue plus. 26 00:01:44,360 --> 00:01:47,960 Speaker 1: Unlike a comet or commercial airplane, a supernova won't waver 27 00:01:48,080 --> 00:01:54,760 Speaker 1: from its position. But how do stars self destruct so spectacularly? 28 00:01:55,800 --> 00:01:59,600 Speaker 1: Let's talk about a giant stars life cycle. A giant 29 00:01:59,600 --> 00:02:02,800 Speaker 1: stars starts out when gas and dust buckle under an 30 00:02:02,880 --> 00:02:07,760 Speaker 1: assertive gravitational pull to form a baby star. As the 31 00:02:07,800 --> 00:02:10,720 Speaker 1: material at the center of a fledgling star heats, it 32 00:02:10,760 --> 00:02:14,880 Speaker 1: attracts more interstellar gas and dust. This growth phase can 33 00:02:14,960 --> 00:02:18,160 Speaker 1: take up to fifty million years, followed by another ten 34 00:02:18,200 --> 00:02:22,959 Speaker 1: billion years of shiny adulthood. Stars are fueled by the 35 00:02:23,040 --> 00:02:26,840 Speaker 1: nuclear fusion of hydrogen into the slightly denser and heavier 36 00:02:26,880 --> 00:02:30,840 Speaker 1: element helium. The fusion takes place in the star's core, 37 00:02:31,120 --> 00:02:34,520 Speaker 1: and the energy it produces flows outward, creating the star's 38 00:02:34,560 --> 00:02:38,360 Speaker 1: observable glow and preventing the heavy core from collapsing in 39 00:02:38,440 --> 00:02:42,560 Speaker 1: on itself. When a star starts running out of hydrogen 40 00:02:42,639 --> 00:02:45,640 Speaker 1: to fuse into helium, it's the beginning of the end. 41 00:02:46,120 --> 00:02:49,799 Speaker 1: With less energy radiating outward, the core begins to collapse, 42 00:02:50,040 --> 00:02:54,400 Speaker 1: causing its temperature to spike. Hydrogen fusion continues only in 43 00:02:54,400 --> 00:02:57,600 Speaker 1: the star's outer layers, which causes it to expand it 44 00:02:57,639 --> 00:03:02,639 Speaker 1: becomes a red giant. A red giant will lose its 45 00:03:02,639 --> 00:03:05,919 Speaker 1: outer layers, either by consuming them or releasing them into 46 00:03:05,919 --> 00:03:10,280 Speaker 1: space to become a white dwarf. A white dwarf with 47 00:03:10,360 --> 00:03:14,960 Speaker 1: enough mass will eventually go supernova. Its core will collapse, 48 00:03:15,240 --> 00:03:18,560 Speaker 1: resulting in an explosion that can't compare to any we 49 00:03:18,639 --> 00:03:22,120 Speaker 1: might experience on Earth, unless we were to bundle a 50 00:03:22,200 --> 00:03:25,359 Speaker 1: few Octilian nuclear warheads and detonate them all at the 51 00:03:25,400 --> 00:03:28,280 Speaker 1: same time. Our own Sun isn't big enough to go 52 00:03:28,360 --> 00:03:32,840 Speaker 1: out with such a bang, but stars that are are 53 00:03:32,880 --> 00:03:37,360 Speaker 1: separated into two supernova classes, type one and type two. 54 00:03:38,200 --> 00:03:40,840 Speaker 1: Astronomers learn a lot about stars from the colors of 55 00:03:40,920 --> 00:03:44,080 Speaker 1: life that they emit. Using a device called a spectrograph, 56 00:03:44,160 --> 00:03:47,040 Speaker 1: they can get a clear picture of exactly what elements 57 00:03:47,040 --> 00:03:52,200 Speaker 1: are burning inside a star. In the nineteen forties, astronomers 58 00:03:52,240 --> 00:03:56,200 Speaker 1: noticed that some supernova type one do not contain hydrogen, 59 00:03:56,640 --> 00:04:00,280 Speaker 1: but the others do. Those are type two. In the 60 00:04:00,360 --> 00:04:05,240 Speaker 1: nineteen eighties, as observational technology improved, scientists further divided type 61 00:04:05,240 --> 00:04:10,120 Speaker 1: one supernova into three subcategories, Type one A, which contains 62 00:04:10,160 --> 00:04:13,880 Speaker 1: silicon in their spectra, Type one B, which contain helium, 63 00:04:14,160 --> 00:04:19,320 Speaker 1: and type one C, which contain neither. The stars lose 64 00:04:19,360 --> 00:04:22,520 Speaker 1: elements when stellar winds rip their outer layers away long 65 00:04:22,560 --> 00:04:28,680 Speaker 1: before they go supernova. A Type one A supernova work 66 00:04:28,839 --> 00:04:31,960 Speaker 1: differently than all the other types. A Type one A 67 00:04:32,120 --> 00:04:34,760 Speaker 1: supernova results from a white dwarf that's part of a 68 00:04:34,800 --> 00:04:37,680 Speaker 1: binary system, that is, one that shares an orbit with 69 00:04:37,720 --> 00:04:40,600 Speaker 1: another star and was about twice the size of our 70 00:04:40,640 --> 00:04:44,719 Speaker 1: Sun during its life. The white dwarf's mass allows it 71 00:04:44,760 --> 00:04:48,120 Speaker 1: to fuse elements slightly heavier than hydrogen, so it has 72 00:04:48,160 --> 00:04:52,880 Speaker 1: a stable core of carbon and oxygen. Left to its 73 00:04:52,880 --> 00:04:56,400 Speaker 1: own devices, this white dwarf would eventually decay into a 74 00:04:56,480 --> 00:05:00,320 Speaker 1: black dwarf, but since it's not alone, it has access 75 00:05:00,360 --> 00:05:04,120 Speaker 1: to resources that other stars don't. The more massive of 76 00:05:04,120 --> 00:05:07,480 Speaker 1: the two stars acts like an opportunistic sibling, using its 77 00:05:07,480 --> 00:05:12,279 Speaker 1: gravitational pull to steal matter from the other star. This 78 00:05:12,480 --> 00:05:16,559 Speaker 1: gluttonous star grows until it exceeds what's called the Chindra 79 00:05:16,680 --> 00:05:20,320 Speaker 1: Shaykhar limit, after the guy who discovered it. It's a 80 00:05:20,400 --> 00:05:23,000 Speaker 1: mass of one point four times that of our self, 81 00:05:23,360 --> 00:05:27,240 Speaker 1: otherwise known as one point four solar masses. At this size, 82 00:05:27,320 --> 00:05:30,719 Speaker 1: the white dwarf suddenly has enough heat and pressure in 83 00:05:30,760 --> 00:05:34,040 Speaker 1: its core to fuse carbon, and all of that carbon 84 00:05:34,120 --> 00:05:38,039 Speaker 1: fuses at once, like a thermonuclear bomb going off, blowing 85 00:05:38,120 --> 00:05:41,960 Speaker 1: the star to bits. It leaves behind a gaseous remnant 86 00:05:42,000 --> 00:05:44,919 Speaker 1: that's symmetrical in shape and contains a great deal of 87 00:05:45,000 --> 00:05:51,200 Speaker 1: iron created in the heat of the explosion. Because type 88 00:05:51,240 --> 00:05:54,320 Speaker 1: one A supernovae all explode at the same point in 89 00:05:54,360 --> 00:05:58,039 Speaker 1: their stellar deaths, they all peak at almost exactly the 90 00:05:58,080 --> 00:06:02,240 Speaker 1: same brightness. It's so consistent that type one A supernova 91 00:06:02,360 --> 00:06:06,760 Speaker 1: are also called standard candles. Once astronomers find one in 92 00:06:06,800 --> 00:06:08,880 Speaker 1: a region of space, they can use it as a 93 00:06:08,880 --> 00:06:12,640 Speaker 1: baseline with which to compare and learn about other objects 94 00:06:12,640 --> 00:06:19,279 Speaker 1: around it. Type one, B, one C, and type two supernova, 95 00:06:19,480 --> 00:06:23,240 Speaker 1: despite showing different elements in their spectra, all explode the 96 00:06:23,279 --> 00:06:28,239 Speaker 1: same way. They start out so huge, possibly eight times 97 00:06:28,240 --> 00:06:31,039 Speaker 1: the size of our Sun that they cannibalize themselves to 98 00:06:31,080 --> 00:06:35,080 Speaker 1: the point of collapse. A white dwarf eventually created from 99 00:06:35,080 --> 00:06:38,080 Speaker 1: a star that massive, has so much heat and pressure 100 00:06:38,120 --> 00:06:42,520 Speaker 1: inside its core that lighter elements keep fusing into increasingly 101 00:06:42,560 --> 00:06:47,280 Speaker 1: heavy elements instead of flying off into space. This produces 102 00:06:47,440 --> 00:06:52,039 Speaker 1: enough radiating energy to support the star's increasing weight until 103 00:06:52,520 --> 00:06:57,719 Speaker 1: iron forms. The fusion of iron into heavier elements actually 104 00:06:57,839 --> 00:07:01,600 Speaker 1: uses energy rather than giving it off, so when iron 105 00:07:01,680 --> 00:07:05,080 Speaker 1: begins to fuse, the star's outer layers lose their support 106 00:07:05,200 --> 00:07:09,920 Speaker 1: and begin to fall inward. To understand the huge explosion 107 00:07:09,960 --> 00:07:12,400 Speaker 1: that results, you have to know what's going on with 108 00:07:12,440 --> 00:07:17,920 Speaker 1: the star's tiniest particles. When a white dwarf is massive 109 00:07:18,000 --> 00:07:20,960 Speaker 1: enough to fuse the iron in its core, those iron 110 00:07:21,000 --> 00:07:25,400 Speaker 1: atoms are incredibly hot and densely packed, squashed together like 111 00:07:25,600 --> 00:07:29,480 Speaker 1: sweaty clowns stuck in a circus car. Their sub atomic 112 00:07:29,520 --> 00:07:34,040 Speaker 1: particles collide and the iron atom's nuclei split, leaving behind 113 00:07:34,120 --> 00:07:38,400 Speaker 1: helium nuclei plus a few leftover neutrons, and absorbing a 114 00:07:38,520 --> 00:07:43,360 Speaker 1: lot of energy in the process. That energy was holding 115 00:07:43,480 --> 00:07:46,920 Speaker 1: the star's core up, so without it, the core starts 116 00:07:46,920 --> 00:07:50,440 Speaker 1: shrinking rapidly. It goes from a diameter of some five 117 00:07:50,480 --> 00:07:55,160 Speaker 1: thousand miles to only twelve miles real Suddenly that's about 118 00:07:55,200 --> 00:08:00,840 Speaker 1: eight thousand kilometers to just nineteen. This creates temperature somewhere 119 00:08:00,840 --> 00:08:03,360 Speaker 1: in the region of one hundred and eighty billion degrees 120 00:08:03,440 --> 00:08:06,400 Speaker 1: fahrenheit or one hundred billion degrees celsius, though at that 121 00:08:06,440 --> 00:08:11,000 Speaker 1: point who's really counting. The heat causes protons and electrons 122 00:08:11,000 --> 00:08:14,400 Speaker 1: to fuse together, canceling each other out to become neutrons 123 00:08:14,560 --> 00:08:18,000 Speaker 1: and expelling a bunch of neutrinos in the process. The 124 00:08:18,040 --> 00:08:21,280 Speaker 1: neutrinos can escape, so they do, leaving the core with 125 00:08:21,320 --> 00:08:25,080 Speaker 1: even less energy to hold itself up. The core contracts 126 00:08:25,120 --> 00:08:27,640 Speaker 1: as much as it physically can, but the star's outer 127 00:08:27,760 --> 00:08:30,920 Speaker 1: layers keep falling inward even after there's no more room. 128 00:08:31,800 --> 00:08:37,840 Speaker 1: That's when they rebound in that enormous explosion. All of 129 00:08:37,880 --> 00:08:40,520 Speaker 1: that took a lot of words to explain, but it 130 00:08:40,520 --> 00:08:45,400 Speaker 1: can happen in as little as a quarter of a second. 131 00:08:45,960 --> 00:08:48,840 Speaker 1: The explosion is hot enough to fuse elements far heavier 132 00:08:48,840 --> 00:08:51,600 Speaker 1: than iron, and it releases these elements in a gaseous 133 00:08:51,600 --> 00:08:54,960 Speaker 1: cloud that will become an asymmetrical remnant around the remaining 134 00:08:55,240 --> 00:09:01,280 Speaker 1: solid core. What happens next depends on how massive the 135 00:09:01,320 --> 00:09:05,000 Speaker 1: original star was. If its inner core was less than 136 00:09:05,080 --> 00:09:08,080 Speaker 1: three solar masses, it creates a neutron star with a 137 00:09:08,080 --> 00:09:11,040 Speaker 1: core about as dense as an atom's nucleus and a 138 00:09:11,120 --> 00:09:16,040 Speaker 1: powerful magnetic field. If its magnetic field creates lighthouse style 139 00:09:16,120 --> 00:09:19,480 Speaker 1: beams of radiation that flash toward Earth as the star rotates, 140 00:09:19,679 --> 00:09:23,640 Speaker 1: it's called a pulsar. But when a star with the 141 00:09:23,640 --> 00:09:27,199 Speaker 1: core equal to three solar masses or more explodes, that 142 00:09:27,240 --> 00:09:31,400 Speaker 1: can result in a black hole. A scientist's hypothesize that 143 00:09:31,480 --> 00:09:34,959 Speaker 1: black holes form when gravity causes the stars compressed inner 144 00:09:34,960 --> 00:09:38,880 Speaker 1: core to continually sink into itself. A black hole has 145 00:09:38,920 --> 00:09:42,079 Speaker 1: such powerful gravitational force that it can drag surrounding matter, 146 00:09:42,320 --> 00:09:47,959 Speaker 1: even planets, stars, and light itself into its mall, all 147 00:09:48,000 --> 00:09:50,760 Speaker 1: of their powers of destruction. Aside, a lot of good 148 00:09:50,800 --> 00:09:54,000 Speaker 1: can come of a supernova, and by tracking the demise 149 00:09:54,040 --> 00:09:58,440 Speaker 1: of particular stars, scientists have uncovered ancient astronomical events and 150 00:09:58,520 --> 00:10:02,400 Speaker 1: predicted future changes in the uns. And by using type 151 00:10:02,400 --> 00:10:06,000 Speaker 1: one A supernova as standard candles, researchers have been able 152 00:10:06,040 --> 00:10:09,560 Speaker 1: to map entire galaxies distances from us and determine that 153 00:10:09,600 --> 00:10:15,440 Speaker 1: the universe is in fact expanding ever more rapidly. But 154 00:10:15,800 --> 00:10:19,719 Speaker 1: of course, exploding stars leave more than just an electromagnetic 155 00:10:19,760 --> 00:10:25,040 Speaker 1: signature behind. They also produce cosmic debris and dust. Type 156 00:10:25,040 --> 00:10:27,679 Speaker 1: one a supernova are thought to be responsible for the 157 00:10:27,760 --> 00:10:31,320 Speaker 1: large amount of iron in the universe, and all of 158 00:10:31,320 --> 00:10:33,640 Speaker 1: the elements in the universe that are heavier than iron, 159 00:10:33,760 --> 00:10:36,960 Speaker 1: from cobalt to rent genium, are thought to be created 160 00:10:37,040 --> 00:10:42,320 Speaker 1: during core collapse supernova explosions. After millions of years, these 161 00:10:42,360 --> 00:10:46,080 Speaker 1: remnants commingle with space gas to form new interstellar life 162 00:10:46,679 --> 00:10:50,840 Speaker 1: baby stars that mature, age and may eventually complete the 163 00:10:50,960 --> 00:10:59,560 Speaker 1: circle of life by becoming a supernova themselves. Today's episode 164 00:10:59,559 --> 00:11:02,720 Speaker 1: is based on article how supernova works on HowStuffWorks dot com, 165 00:11:02,760 --> 00:11:06,000 Speaker 1: written by Laureel Dove. Brain Stuff is production of iHeartRadio 166 00:11:06,040 --> 00:11:08,320 Speaker 1: in partnership with how stuffworks dot Com and is produced 167 00:11:08,320 --> 00:11:11,720 Speaker 1: by Tyler Klang. For more podcasts my heart Radio, visit 168 00:11:11,760 --> 00:11:14,720 Speaker 1: the iHeartRadio app, Apple Podcasts, or wherever you listen to 169 00:11:14,760 --> 00:11:15,679 Speaker 1: your favorite shows.