1 00:00:00,000 --> 00:00:03,660 Welcome back to Cosmos in a Pod, Space, and Astronomy series. 2 00:00:03,660 --> 00:00:05,360 When we look up at the night sky, 3 00:00:05,360 --> 00:00:08,720 it's easy to think of stars as just these tiny twinkling 4 00:00:08,720 --> 00:00:10,160 points of light. 5 00:00:10,160 --> 00:00:13,120 But the reality is way more spectacular. 6 00:00:13,120 --> 00:00:15,480 Today's deep dive is all about uncovering 7 00:00:15,480 --> 00:00:19,280 the mind-blowing diversity of stars that fill our universe. 8 00:00:19,280 --> 00:00:21,360 It really is a cosmic zoo out there, 9 00:00:21,360 --> 00:00:24,040 everything from tiny, cool red dwarfs that 10 00:00:24,040 --> 00:00:27,800 could outlive our galaxy to colossal supergiants 11 00:00:27,800 --> 00:00:30,760 that blaze with the intensity of millions of suns. 12 00:00:30,760 --> 00:00:32,440 Wow, millions of suns. 13 00:00:32,440 --> 00:00:33,960 OK, I am hooked already. 14 00:00:33,960 --> 00:00:35,920 So how do astronomers even begin to make 15 00:00:35,920 --> 00:00:37,720 sense of this incredible variety? 16 00:00:37,720 --> 00:00:39,440 Where do you even start when you're 17 00:00:39,440 --> 00:00:41,120 trying to categorize stars? 18 00:00:41,120 --> 00:00:42,400 It is a challenge for sure. 19 00:00:42,400 --> 00:00:43,960 But astronomers are clever folks. 20 00:00:43,960 --> 00:00:45,460 They've come up with a system that's 21 00:00:45,460 --> 00:00:47,320 like a stellar fingerprint analysis. 22 00:00:47,320 --> 00:00:49,720 It's called the Morgan-Keynian classification system, 23 00:00:49,720 --> 00:00:51,000 or MK for short. 24 00:00:51,000 --> 00:00:51,520 MK. 25 00:00:51,520 --> 00:00:53,560 So that's how they keep track of all these stellar suspects, 26 00:00:53,560 --> 00:00:54,320 huh? 27 00:00:54,320 --> 00:00:56,560 What's the secret behind this MK system? 28 00:00:56,560 --> 00:00:57,480 Think of it like this. 29 00:00:57,480 --> 00:00:59,280 Every star emits light, right? 30 00:00:59,280 --> 00:01:01,840 And that light carries a unique signature, 31 00:01:01,840 --> 00:01:04,680 a spectrum that tells us a lot about the star's temperature, 32 00:01:04,680 --> 00:01:07,360 chemical composition, and even its motion. 33 00:01:07,360 --> 00:01:10,920 So it's like a star's personal ID card encoded in light. 34 00:01:10,920 --> 00:01:11,640 That's pretty cool. 35 00:01:11,640 --> 00:01:12,880 Exactly. 36 00:01:12,880 --> 00:01:15,840 And this MK system uses these spectral clues 37 00:01:15,840 --> 00:01:17,760 to sort stars into different categories, 38 00:01:17,760 --> 00:01:19,400 each designated by a letter. 39 00:01:19,400 --> 00:01:20,320 OK, spill the beans. 40 00:01:20,320 --> 00:01:21,960 What are these stellar categories? 41 00:01:21,960 --> 00:01:24,800 Get ready for a cosmic alphabet soup. 42 00:01:24,800 --> 00:01:29,640 O, B, A, F, G, K, and M. And just to make it easier 43 00:01:29,640 --> 00:01:32,560 to remember, there's this handy and mnemonic, 44 00:01:32,560 --> 00:01:34,960 oh, be a fine girl, guy. 45 00:01:34,960 --> 00:01:36,240 Kiss me. 46 00:01:36,240 --> 00:01:36,960 Huh. 47 00:01:36,960 --> 00:01:38,640 That's definitely one way to remember it. 48 00:01:38,640 --> 00:01:40,720 So is this sequence telling us something 49 00:01:40,720 --> 00:01:42,040 about the stars themselves? 50 00:01:42,040 --> 00:01:43,080 It absolutely is. 51 00:01:43,080 --> 00:01:45,600 It's essentially a temperature scale, from hottest 52 00:01:45,600 --> 00:01:46,320 to coolest. 53 00:01:46,320 --> 00:01:49,120 At one end of the spectrum, you have the O-type stars, 54 00:01:49,120 --> 00:01:51,200 the hottest and most massive. 55 00:01:51,200 --> 00:01:53,240 They're burning with such intense energy 56 00:01:53,240 --> 00:01:55,640 that they glow with a brilliant blue-white light. 57 00:01:55,640 --> 00:01:59,000 Their surface temperatures can exceed a scorching 30,000 58 00:01:59,000 --> 00:01:59,600 Kelvin. 59 00:01:59,600 --> 00:02:00,720 30,000 Kelvin. 60 00:02:00,720 --> 00:02:02,560 Wow, that's hot. 61 00:02:02,560 --> 00:02:03,520 Can you even imagine? 62 00:02:03,520 --> 00:02:04,120 Right. 63 00:02:04,120 --> 00:02:06,200 And then as you move down the spectral ladder, 64 00:02:06,200 --> 00:02:07,600 things start to cool down. 65 00:02:07,600 --> 00:02:11,440 We pass through the B-type stars, then A, then F, 66 00:02:11,440 --> 00:02:14,360 each getting progressively cooler and changing color. 67 00:02:14,360 --> 00:02:17,000 So like the colors of a rainbow, but in stars. 68 00:02:17,000 --> 00:02:18,000 Exactly. 69 00:02:18,000 --> 00:02:20,120 It's a beautiful spectrum, really. 70 00:02:20,120 --> 00:02:24,000 And finally, at the cooler end, we reach the M-type stars. 71 00:02:24,000 --> 00:02:26,000 These are the red dwarfs we talked about earlier, 72 00:02:26,000 --> 00:02:28,760 and they're much more laid back than their hot blue cousins. 73 00:02:28,760 --> 00:02:32,200 Their surface temperatures can be as low as 3,000 Kelvin. 74 00:02:32,200 --> 00:02:35,320 That's still incredibly hot, but it's definitely a far cry 75 00:02:35,320 --> 00:02:37,520 from 30,000 Kelvin. 76 00:02:37,520 --> 00:02:40,920 So where does our sun fall on this cosmic temperature scale? 77 00:02:40,920 --> 00:02:42,600 Well, our sun is a pretty average star. 78 00:02:42,600 --> 00:02:44,680 It's a G-type star, comfortably nestled 79 00:02:44,680 --> 00:02:46,680 in the middle of the spectral sequence. 80 00:02:46,680 --> 00:02:49,960 With a surface temperature of around 5,800 Kelvin, 81 00:02:49,960 --> 00:02:53,480 it's not too hot, not too cold, just right for supporting life 82 00:02:53,480 --> 00:02:55,040 on Earth, as far as we know. 83 00:02:55,040 --> 00:02:57,120 Goldilocks approved. 84 00:02:57,120 --> 00:02:59,280 So we have this whole spectrum of stars, 85 00:02:59,280 --> 00:03:01,320 each with its unique characteristics. 86 00:03:01,320 --> 00:03:02,600 Where do we go from here? 87 00:03:02,600 --> 00:03:04,720 What are some of the most intriguing types 88 00:03:04,720 --> 00:03:05,760 of stars out there? 89 00:03:05,760 --> 00:03:07,440 Well, if you're looking for the most common star 90 00:03:07,440 --> 00:03:10,520 in the universe, look no further than the humble red dwarf. 91 00:03:10,520 --> 00:03:13,960 These cool, faint stars make up something like 70% to 80% 92 00:03:13,960 --> 00:03:15,600 of all stars in our galaxy. 93 00:03:15,600 --> 00:03:16,560 Wow, that many. 94 00:03:16,560 --> 00:03:19,680 So they're kind of like the cosmic underdogs, quietly 95 00:03:19,680 --> 00:03:21,960 dominating the stellar population. 96 00:03:21,960 --> 00:03:23,040 Exactly. 97 00:03:23,040 --> 00:03:24,680 And what's really fascinating about them 98 00:03:24,680 --> 00:03:26,760 is their incredible longevity. 99 00:03:26,760 --> 00:03:29,280 They burn their hydrogen fuel so slowly 100 00:03:29,280 --> 00:03:33,560 that their lifespans can stretch into trillions of years. 101 00:03:33,560 --> 00:03:36,360 That's thousands of times longer than our sun's expected 102 00:03:36,360 --> 00:03:36,920 lifetime. 103 00:03:36,920 --> 00:03:38,480 Trillions of years. 104 00:03:38,480 --> 00:03:39,880 That's mind boggling. 105 00:03:39,880 --> 00:03:42,640 So they're like the tortoises of the cosmos, slowly 106 00:03:42,640 --> 00:03:44,360 and steadily shining for eons. 107 00:03:44,360 --> 00:03:45,880 That's a perfect analogy. 108 00:03:45,880 --> 00:03:48,800 And this incredible longevity has some really interesting 109 00:03:48,800 --> 00:03:52,000 implications, especially when we think about the possibility 110 00:03:52,000 --> 00:03:53,480 of life on other planets. 111 00:03:53,480 --> 00:03:54,840 Ooh, intriguing. 112 00:03:54,840 --> 00:03:57,440 Why would their long lifespan matter for life? 113 00:03:57,440 --> 00:03:58,040 Think about it. 114 00:03:58,040 --> 00:03:59,920 On Earth, it took billions of years 115 00:03:59,920 --> 00:04:02,120 for life to evolve from simple microbes 116 00:04:02,120 --> 00:04:04,240 to complex organisms like us. 117 00:04:04,240 --> 00:04:07,440 If a star lived only a few million or billion years, 118 00:04:07,440 --> 00:04:09,200 it's unlikely that life on its planets 119 00:04:09,200 --> 00:04:12,000 would have enough time to reach that level of complexity. 120 00:04:12,000 --> 00:04:12,840 That makes sense. 121 00:04:12,840 --> 00:04:15,800 So red dwarfs, with their incredibly long lifestands, 122 00:04:15,800 --> 00:04:18,280 could provide the stable environments needed for life 123 00:04:18,280 --> 00:04:20,440 to really take hold and flourish. 124 00:04:20,440 --> 00:04:21,360 That's pretty cool. 125 00:04:21,360 --> 00:04:22,120 It is. 126 00:04:22,120 --> 00:04:25,000 And there's growing evidence to support this idea. 127 00:04:25,000 --> 00:04:27,680 We've discovered planets orbiting red dwarfs, some 128 00:04:27,680 --> 00:04:30,040 even within the habitable zone, where temperatures 129 00:04:30,040 --> 00:04:33,160 could allow for liquid water, a key ingredient for life 130 00:04:33,160 --> 00:04:34,120 as we know it. 131 00:04:34,120 --> 00:04:37,320 So these seemingly insignificant stars 132 00:04:37,320 --> 00:04:40,520 might be holding the keys to unlocking the secrets of life 133 00:04:40,520 --> 00:04:41,320 beyond Earth. 134 00:04:41,320 --> 00:04:42,080 I love that. 135 00:04:42,080 --> 00:04:43,720 It's certainly a possibility. 136 00:04:43,720 --> 00:04:46,160 And it just goes to show that we shouldn't judge a star 137 00:04:46,160 --> 00:04:47,880 by its size or brightness. 138 00:04:47,880 --> 00:04:49,800 Even the smallest and faintest stars 139 00:04:49,800 --> 00:04:51,720 can hold incredible secrets. 140 00:04:51,720 --> 00:04:52,920 That's a great point. 141 00:04:52,920 --> 00:04:55,480 But what about stars like our sun? 142 00:04:55,480 --> 00:04:57,760 Where do they fit into this cosmic picture? 143 00:04:57,760 --> 00:05:00,160 Well, our sun, along with a good chunk of the stars 144 00:05:00,160 --> 00:05:02,400 you see in the night sky, belong to a category 145 00:05:02,400 --> 00:05:04,560 called main sequence stars. 146 00:05:04,560 --> 00:05:06,920 These stars are in the prime of their lives, you could say. 147 00:05:06,920 --> 00:05:07,880 Prime of their lives. 148 00:05:07,880 --> 00:05:09,320 What does that mean for a star? 149 00:05:09,320 --> 00:05:11,840 It means they're busy fusing hydrogen 150 00:05:11,840 --> 00:05:13,880 into helium in their cores, releasing 151 00:05:13,880 --> 00:05:16,320 vast amounts of energy in the process. 152 00:05:16,320 --> 00:05:18,920 This is what makes them shine so brightly. 153 00:05:18,920 --> 00:05:21,080 So they're the cosmic powerhouses, 154 00:05:21,080 --> 00:05:23,040 the ones keeping the lights on in the universe. 155 00:05:23,040 --> 00:05:23,920 Exactly. 156 00:05:23,920 --> 00:05:26,800 And they come in a range of sizes and temperatures, 157 00:05:26,800 --> 00:05:29,640 all following this pattern of hydrogen fusion. 158 00:05:29,640 --> 00:05:32,400 Our sun, as a G-type main sequence star, 159 00:05:32,400 --> 00:05:35,600 is kind of middle of the road in terms of temperature and size. 160 00:05:35,600 --> 00:05:38,520 So we're not the most dazzling star in the galaxy, 161 00:05:38,520 --> 00:05:40,560 but we're getting the job done. 162 00:05:40,560 --> 00:05:41,760 That's the way to look at it. 163 00:05:41,760 --> 00:05:44,880 And remember, main sequence stars like our sun 164 00:05:44,880 --> 00:05:47,520 are incredibly important because they're stable. 165 00:05:47,520 --> 00:05:50,000 They provide the long-term energy and stability 166 00:05:50,000 --> 00:05:52,920 that planetary systems like ours need to exist. 167 00:05:52,920 --> 00:05:55,440 Right, because without that stable energy source, 168 00:05:55,440 --> 00:05:57,880 we wouldn't be here having this conversation. 169 00:05:57,880 --> 00:05:59,520 But I imagine there are stars out there 170 00:05:59,520 --> 00:06:01,280 that are a bit more dramatic. 171 00:06:01,280 --> 00:06:03,960 What about those stars that really grab our attention 172 00:06:03,960 --> 00:06:06,360 with their sheer size and brilliance? 173 00:06:06,360 --> 00:06:07,840 Yes, you're talking about the giants 174 00:06:07,840 --> 00:06:09,680 and supergents of the cosmos. 175 00:06:09,680 --> 00:06:11,480 These are the stars that have graduated 176 00:06:11,480 --> 00:06:13,120 from the main sequence and are entering 177 00:06:13,120 --> 00:06:15,880 a new, more flamboyant chapter of their lives. 178 00:06:15,880 --> 00:06:16,920 Flamboyant. 179 00:06:16,920 --> 00:06:18,040 That sounds exciting. 180 00:06:18,040 --> 00:06:20,160 Tell me more about these stellar celebrities. 181 00:06:20,160 --> 00:06:22,080 Well, first we have the red giants. 182 00:06:22,080 --> 00:06:25,080 These are stars, often similar in mass to our sun, 183 00:06:25,080 --> 00:06:28,720 that have exhausted most of the hydrogen fuel in their cores. 184 00:06:28,720 --> 00:06:30,680 As they start to fuse helium, they 185 00:06:30,680 --> 00:06:32,720 undergo a dramatic transformation. 186 00:06:32,720 --> 00:06:33,720 Dramatic in what way? 187 00:06:33,720 --> 00:06:34,760 What happens to them? 188 00:06:34,760 --> 00:06:37,720 They begin to expand, and I mean really expand. 189 00:06:37,720 --> 00:06:40,480 They can swell up to hundreds of times their original size. 190 00:06:40,480 --> 00:06:42,400 Think of it like a balloon inflating. 191 00:06:42,400 --> 00:06:45,040 And as they expand, their surface cools down, 192 00:06:45,040 --> 00:06:47,360 giving them that characteristic reddish hue. 193 00:06:47,360 --> 00:06:50,120 So they're like giant glowing orbs in space. 194 00:06:50,120 --> 00:06:51,760 I can see why they grab our attention. 195 00:06:51,760 --> 00:06:52,440 Exactly. 196 00:06:52,440 --> 00:06:55,000 And one of the most famous examples of a red giant 197 00:06:55,000 --> 00:06:59,080 is Betelgeuse, the bright red star in the constellation Orion. 198 00:06:59,080 --> 00:07:00,000 Betelgeuse. 199 00:07:00,000 --> 00:07:01,640 I've definitely heard of that one. 200 00:07:01,640 --> 00:07:04,480 It's amazing to think that a star we can see with the naked eye 201 00:07:04,480 --> 00:07:07,120 is going through such a dramatic transformation. 202 00:07:07,120 --> 00:07:07,920 It is. 203 00:07:07,920 --> 00:07:09,920 And when we look at Betelgeuse, we're 204 00:07:09,920 --> 00:07:12,160 seeing a glimpse into our sun's future. 205 00:07:12,160 --> 00:07:14,280 In about 5 billion years, our sun 206 00:07:14,280 --> 00:07:17,440 will also become a red giant, expanding and engulfing 207 00:07:17,440 --> 00:07:20,080 the inner planets, including Mercury and Venus. 208 00:07:20,080 --> 00:07:21,480 Whoa. 209 00:07:21,480 --> 00:07:23,440 That's a little scary to think about, 210 00:07:23,440 --> 00:07:26,040 but also incredibly fascinating. 211 00:07:26,040 --> 00:07:28,320 So red giants are pretty impressive, 212 00:07:28,320 --> 00:07:30,840 but I bet the supergiants are even more mind blowing. 213 00:07:30,840 --> 00:07:32,120 Oh, you have no idea. 214 00:07:32,120 --> 00:07:34,960 Supergiants are the true heavyweights of the cosmos. 215 00:07:34,960 --> 00:07:37,720 They're formed from stars at least 10 times more 216 00:07:37,720 --> 00:07:38,960 massive than our sun. 217 00:07:38,960 --> 00:07:40,080 10 times more massive. 218 00:07:40,080 --> 00:07:41,720 That's already huge. 219 00:07:41,720 --> 00:07:44,240 And what happens when these monsters run out of fuel? 220 00:07:44,240 --> 00:07:46,040 Well, get ready for this. 221 00:07:46,040 --> 00:07:49,000 They expand to truly colossal sizes, sometimes 222 00:07:49,000 --> 00:07:51,600 exceeding 1,000 times the radius of our sun. 223 00:07:51,600 --> 00:07:53,560 1,000 times the radius of our sun. 224 00:07:53,560 --> 00:07:55,880 That's like unimaginable. 225 00:07:55,880 --> 00:07:57,600 It must take an insane amount of energy 226 00:07:57,600 --> 00:07:59,000 to power a star that big. 227 00:07:59,000 --> 00:07:59,500 It does. 228 00:07:59,500 --> 00:08:01,440 Supergiants are incredibly luminous, 229 00:08:01,440 --> 00:08:03,840 shining with the light of millions of suns. 230 00:08:03,840 --> 00:08:05,680 They're the rock stars of the universe, 231 00:08:05,680 --> 00:08:07,440 burning bright and living fast. 232 00:08:07,440 --> 00:08:08,720 Burning bright and living fast. 233 00:08:08,720 --> 00:08:11,080 Is that why we see them so clearly in the night sky? 234 00:08:11,080 --> 00:08:13,040 That's part of it, but it's also because they're 235 00:08:13,040 --> 00:08:14,480 relatively rare. 236 00:08:14,480 --> 00:08:17,200 Their intense energy output comes at a price. 237 00:08:17,200 --> 00:08:19,640 They burn through their fuel at a much faster rate 238 00:08:19,640 --> 00:08:22,500 than smaller stars, so their lifespans are much shorter. 239 00:08:22,500 --> 00:08:25,080 Only a few million to tens of millions of years, 240 00:08:25,080 --> 00:08:26,400 astronomically speaking. 241 00:08:26,400 --> 00:08:28,800 Wow, so they're like the cosmic fireworks, 242 00:08:28,800 --> 00:08:31,640 putting on a spectacular show, but fading away 243 00:08:31,640 --> 00:08:33,480 much more quickly. 244 00:08:33,480 --> 00:08:35,680 It's amazing how diverse stars can be. 245 00:08:35,680 --> 00:08:39,620 So we've got red dwarfs, main sequence stars like our sun, 246 00:08:39,620 --> 00:08:41,920 and these incredible giants and supergiants. 247 00:08:41,920 --> 00:08:43,920 What happens next in a star's life? 248 00:08:43,920 --> 00:08:45,360 Where do they go from there? 249 00:08:45,360 --> 00:08:47,160 That's where things get even more interesting, 250 00:08:47,160 --> 00:08:49,800 but I think that's the story for another part of our deep dive. 251 00:08:49,800 --> 00:08:50,960 You're killing me. 252 00:08:50,960 --> 00:08:53,640 But OK, I guess we have to leave our listeners in suspense 253 00:08:53,640 --> 00:08:54,440 for a bit. 254 00:08:54,440 --> 00:08:57,000 Don't forget to follow and subscribe to Cosmos in a Pod 255 00:08:57,000 --> 00:08:59,800 and our YouTube channel for more cosmic adventures. 256 00:08:59,800 --> 00:09:02,360 We'll be back soon to explore the final chapters 257 00:09:02,360 --> 00:09:04,800 in the lives of stars, and trust me, 258 00:09:04,800 --> 00:09:05,920 you won't want to miss it. 259 00:09:05,920 --> 00:09:07,920 All right, so last time we left you on a cliffhanger. 260 00:09:07,920 --> 00:09:11,120 We talked about how stars evolve from those humble red dwarfs 261 00:09:11,120 --> 00:09:13,440 to those dazzling supergiants. 262 00:09:13,440 --> 00:09:15,800 But as with all things in the universe, 263 00:09:15,800 --> 00:09:17,920 even stars have an expiration date. 264 00:09:17,920 --> 00:09:20,360 And I am ready to learn about the grand finale. 265 00:09:20,360 --> 00:09:23,440 So what happens when a star runs out of fuel? 266 00:09:23,440 --> 00:09:25,280 Is it lights out, game over? 267 00:09:25,280 --> 00:09:26,200 Not necessarily. 268 00:09:26,200 --> 00:09:27,920 It's not a simple off switch. 269 00:09:27,920 --> 00:09:29,940 The way a star ends its life depends 270 00:09:29,940 --> 00:09:31,680 a lot on its starting mass. 271 00:09:31,680 --> 00:09:33,600 OK, so like a cosmic weight class. 272 00:09:33,600 --> 00:09:34,200 Tell me more. 273 00:09:34,200 --> 00:09:35,000 Exactly. 274 00:09:35,000 --> 00:09:37,480 Let's start with the stars that are up to eight times 275 00:09:37,480 --> 00:09:39,320 the mass of our sun. 276 00:09:39,320 --> 00:09:41,800 When they reach the end of their main sequence lives, 277 00:09:41,800 --> 00:09:43,960 they start to shed their outer layers, 278 00:09:43,960 --> 00:09:45,960 like a snake shedding its skin. 279 00:09:45,960 --> 00:09:47,240 A cosmic molting. 280 00:09:47,240 --> 00:09:48,840 That's pretty vivid image. 281 00:09:48,840 --> 00:09:51,720 What's left behind after this stellar striptease? 282 00:09:51,720 --> 00:09:54,280 What remains is the core of the star, 283 00:09:54,280 --> 00:09:58,080 a super dense earth-sized ball of matter called a white dwarf. 284 00:09:58,080 --> 00:09:58,920 A white dwarf. 285 00:09:58,920 --> 00:10:00,400 So it's not really a star anymore. 286 00:10:00,400 --> 00:10:02,360 Well, it's a stellar remnant. 287 00:10:02,360 --> 00:10:04,520 It's no longer generating energy through fusion, 288 00:10:04,520 --> 00:10:08,480 but it's still incredibly hot, glowing with leftover heat. 289 00:10:08,480 --> 00:10:10,080 Imagine squeezing the mass of the sun 290 00:10:10,080 --> 00:10:11,640 into something the size of our planet. 291 00:10:11,640 --> 00:10:13,120 That's incredible. 292 00:10:13,120 --> 00:10:14,080 So dense. 293 00:10:14,080 --> 00:10:15,760 What eventually happens to a white dwarf? 294 00:10:15,760 --> 00:10:16,880 Does it just fade away? 295 00:10:16,880 --> 00:10:19,680 Over billions of years, yes, it will slowly 296 00:10:19,680 --> 00:10:23,840 cool down and dim, eventually becoming a cold, dark object 297 00:10:23,840 --> 00:10:25,240 known as a black dwarf. 298 00:10:25,240 --> 00:10:27,320 So a quiet ending for some stars. 299 00:10:27,320 --> 00:10:29,720 But what about the stars that are more than eight times 300 00:10:29,720 --> 00:10:31,880 the mass of our sun? 301 00:10:31,880 --> 00:10:35,120 I have a feeling their grand finale is a bit more explosive. 302 00:10:35,120 --> 00:10:36,240 You are absolutely right. 303 00:10:36,240 --> 00:10:38,400 These massive stars go out with a bang. 304 00:10:38,400 --> 00:10:39,160 Literally. 305 00:10:39,160 --> 00:10:40,480 We're talking about supernovae. 306 00:10:40,480 --> 00:10:41,080 Supernovae. 307 00:10:41,080 --> 00:10:43,200 Those are the incredibly bright explosions 308 00:10:43,200 --> 00:10:45,160 we sometimes see in distant galaxies, right? 309 00:10:45,160 --> 00:10:46,040 Exactly. 310 00:10:46,040 --> 00:10:48,040 As a massive star runs out of fuel, 311 00:10:48,040 --> 00:10:51,880 its core collapses under its own immense gravity. 312 00:10:51,880 --> 00:10:53,960 This collapse triggers a shock wave 313 00:10:53,960 --> 00:10:56,960 that rips through the star, blasting its outer layers 314 00:10:56,960 --> 00:10:59,640 into space with incredible force. 315 00:10:59,640 --> 00:11:01,400 So it's like a cosmic implosion that 316 00:11:01,400 --> 00:11:03,120 leads to a massive explosion. 317 00:11:03,120 --> 00:11:05,080 It's hard to even wrap my head around the scale 318 00:11:05,080 --> 00:11:06,000 of these events. 319 00:11:06,000 --> 00:11:06,720 It is. 320 00:11:06,720 --> 00:11:09,400 And what's left behind after a supernova 321 00:11:09,400 --> 00:11:11,960 depends on the initial mass of the star. 322 00:11:11,960 --> 00:11:15,560 For stars that are, say, 10 to 20 times the mass of the sun, 323 00:11:15,560 --> 00:11:18,280 the core collapses into an incredibly dense object 324 00:11:18,280 --> 00:11:19,920 called a neutron star. 325 00:11:19,920 --> 00:11:21,320 I've heard of neutron stars. 326 00:11:21,320 --> 00:11:23,360 They're like the ultimate cosmic oddities, right? 327 00:11:23,360 --> 00:11:24,200 Absolutely. 328 00:11:24,200 --> 00:11:26,160 They are some of the most extreme objects 329 00:11:26,160 --> 00:11:27,240 in the universe. 330 00:11:27,240 --> 00:11:30,880 Imagine a sphere only about 10 to 20 kilometers across 331 00:11:30,880 --> 00:11:33,360 that's smaller than a city, but packing in more mass 332 00:11:33,360 --> 00:11:34,840 than our entire sun. 333 00:11:34,840 --> 00:11:37,600 Wait, a city-sized object with more mass than the sun? 334 00:11:37,600 --> 00:11:38,960 How is that even possible? 335 00:11:38,960 --> 00:11:41,560 The gravity in a neutron star is so strong 336 00:11:41,560 --> 00:11:43,600 that it crushes the matter inside, 337 00:11:43,600 --> 00:11:47,760 forcing electrons and protons to combine and form neutrons. 338 00:11:47,760 --> 00:11:49,720 This creates a super dense material 339 00:11:49,720 --> 00:11:52,120 that's unlike anything we find here on Earth. 340 00:11:52,120 --> 00:11:54,120 So it's like a giant atomic nucleus. 341 00:11:54,120 --> 00:11:56,880 I'm starting to understand why they call them neutron stars. 342 00:11:56,880 --> 00:11:57,880 You got it. 343 00:11:57,880 --> 00:12:00,840 And just to get a sense of how extreme these objects are, 344 00:12:00,840 --> 00:12:04,320 imagine taking a teaspoon of neutron star material. 345 00:12:04,320 --> 00:12:07,080 That tiny amount would weigh billions of tons. 346 00:12:07,080 --> 00:12:08,080 Billions of tons. 347 00:12:08,080 --> 00:12:10,720 OK, that's officially mind blowing. 348 00:12:10,720 --> 00:12:12,760 But what about the most massive stars, 349 00:12:12,760 --> 00:12:14,640 the ones that are much bigger than 20 times 350 00:12:14,640 --> 00:12:16,200 the mass of our sun? 351 00:12:16,200 --> 00:12:17,960 Do they also form neutron stars? 352 00:12:17,960 --> 00:12:20,080 That's where things get even weirder. 353 00:12:20,080 --> 00:12:23,440 When these super massive stars explode as supernovae, 354 00:12:23,440 --> 00:12:25,320 their cores collapse so completely 355 00:12:25,320 --> 00:12:26,920 that they form black holes. 356 00:12:26,920 --> 00:12:27,520 Black holes. 357 00:12:27,520 --> 00:12:29,040 I think everyone has heard of black holes, 358 00:12:29,040 --> 00:12:30,400 but they're so hard to grasp. 359 00:12:30,400 --> 00:12:31,520 What exactly are they? 360 00:12:31,520 --> 00:12:34,600 Imagine a region of space time where gravity is so intense 361 00:12:34,600 --> 00:12:37,360 that nothing, not even light, can escape. 362 00:12:37,360 --> 00:12:38,280 That's a black hole. 363 00:12:38,280 --> 00:12:39,800 So it's like a cosmic trap door. 364 00:12:39,800 --> 00:12:42,440 Anything that gets too close disappears forever. 365 00:12:42,440 --> 00:12:43,800 You could think of it that way. 366 00:12:43,800 --> 00:12:46,040 And what's even crazier is that black holes 367 00:12:46,040 --> 00:12:48,760 warp the fabric of space time around them. 368 00:12:48,760 --> 00:12:51,440 It's like dropping a bowling ball on a trampoline. 369 00:12:51,440 --> 00:12:54,360 The fabric stretches and distorts around the massive object. 370 00:12:54,360 --> 00:12:56,840 OK, that's helping me visualize it a bit better, 371 00:12:56,840 --> 00:12:58,560 but it's still pretty mind boggling. 372 00:12:58,560 --> 00:13:03,400 So we have white dwarfs, neutron stars, and black holes, 373 00:13:03,400 --> 00:13:05,840 these remnants of dead stars. 374 00:13:05,840 --> 00:13:08,040 But I feel like we've skipped over some other intriguing 375 00:13:08,040 --> 00:13:09,000 types of stars. 376 00:13:09,000 --> 00:13:11,040 What about variable stars, for example? 377 00:13:11,040 --> 00:13:12,040 Yes. 378 00:13:12,040 --> 00:13:14,560 Variable stars are fascinating because they 379 00:13:14,560 --> 00:13:16,600 change in brightness over time. 380 00:13:16,600 --> 00:13:18,080 They're not just steadily shining. 381 00:13:18,080 --> 00:13:21,240 They pulse, flicker, and sometimes even erupt. 382 00:13:21,240 --> 00:13:24,440 So they're like the cosmic flashers of the universe. 383 00:13:24,440 --> 00:13:26,240 What causes this variability? 384 00:13:26,240 --> 00:13:28,840 There are many different types of variable stars, 385 00:13:28,840 --> 00:13:31,720 and their variability can be caused by a range of factors. 386 00:13:31,720 --> 00:13:34,440 Some stars pulsate because of internal processes, 387 00:13:34,440 --> 00:13:37,040 like changes in their temperature or pressure. 388 00:13:37,040 --> 00:13:38,920 Others might be part of a binary system 389 00:13:38,920 --> 00:13:42,360 where two stars orbit each other and their brightness changes 390 00:13:42,360 --> 00:13:43,840 as they eclipse each other. 391 00:13:43,840 --> 00:13:46,200 So it's like they're putting on a celestial dance, 392 00:13:46,200 --> 00:13:48,200 changing their brightness as they interact. 393 00:13:48,200 --> 00:13:49,560 That's a great way to put it. 394 00:13:49,560 --> 00:13:52,400 And these variable stars are not just pretty to look at. 395 00:13:52,400 --> 00:13:54,760 They're incredibly valuable tools for astronomers. 396 00:13:54,760 --> 00:13:55,280 Tools? 397 00:13:55,280 --> 00:13:56,200 How so? 398 00:13:56,200 --> 00:13:59,480 Well, one type of variable star, called a cepheid variable, 399 00:13:59,480 --> 00:14:02,240 has a special relationship between its pulsation period 400 00:14:02,240 --> 00:14:03,800 and its luminosity. 401 00:14:03,800 --> 00:14:06,480 Basically, the longer the pulsation period, 402 00:14:06,480 --> 00:14:08,080 the brighter the star. 403 00:14:08,080 --> 00:14:10,360 So it's like a cosmic clock that also tells 404 00:14:10,360 --> 00:14:11,480 us how bright the star is. 405 00:14:11,480 --> 00:14:12,520 Exactly. 406 00:14:12,520 --> 00:14:15,240 And knowing a star's luminosity allows astronomers 407 00:14:15,240 --> 00:14:17,640 to calculate its distance from Earth. 408 00:14:17,640 --> 00:14:21,200 This is incredibly useful for mapping out the vast distances 409 00:14:21,200 --> 00:14:22,240 in the universe. 410 00:14:22,240 --> 00:14:24,360 So by studying these blinking stars, 411 00:14:24,360 --> 00:14:27,360 astronomers can measure the vastness of space. 412 00:14:27,360 --> 00:14:28,320 That's pretty clever. 413 00:14:28,320 --> 00:14:29,000 It is. 414 00:14:29,000 --> 00:14:30,800 And there are other types of variable stars, 415 00:14:30,800 --> 00:14:33,720 like RR Lyrae stars, that are useful for studying star 416 00:14:33,720 --> 00:14:36,040 clusters and the evolution of galaxies. 417 00:14:36,040 --> 00:14:37,880 It's amazing how much information 418 00:14:37,880 --> 00:14:40,560 we can glean from these seemingly simple changes 419 00:14:40,560 --> 00:14:42,040 in a star's brightness. 420 00:14:42,040 --> 00:14:43,920 It's like they're sending us coded messages 421 00:14:43,920 --> 00:14:44,920 about the universe. 422 00:14:44,920 --> 00:14:47,320 And then we have some truly unusual stars out there, 423 00:14:47,320 --> 00:14:49,680 like brown dwarfs and magnetars. 424 00:14:49,680 --> 00:14:50,840 Brown dwarfs. 425 00:14:50,840 --> 00:14:52,720 Those are the failed stars, right? 426 00:14:52,720 --> 00:14:54,480 The ones that never quite got massive enough 427 00:14:54,480 --> 00:14:56,280 to ignite nuclear fusion. 428 00:14:56,280 --> 00:14:56,840 That's right. 429 00:14:56,840 --> 00:14:59,400 They're kind of like the in-betweeners of the cosmos. 430 00:14:59,400 --> 00:15:01,640 Not quite planets, not quite stars. 431 00:15:01,640 --> 00:15:03,600 So they're like the cosmic teenagers, 432 00:15:03,600 --> 00:15:05,320 still figuring things out. 433 00:15:05,320 --> 00:15:06,840 You could say that. 434 00:15:06,840 --> 00:15:10,320 And while they might not shine as brightly as stars, 435 00:15:10,320 --> 00:15:13,480 they're still fascinating objects to study. 436 00:15:13,480 --> 00:15:15,560 They can tell us a lot about star formation 437 00:15:15,560 --> 00:15:17,720 and the limits of stellar evolution. 438 00:15:17,720 --> 00:15:20,520 I'm always up for learning about cosmic misfits. 439 00:15:20,520 --> 00:15:21,800 What about magnetars? 440 00:15:21,800 --> 00:15:22,960 Those sound intense. 441 00:15:22,960 --> 00:15:23,760 They are. 442 00:15:23,760 --> 00:15:26,800 Magnetars are neutron stars with incredibly 443 00:15:26,800 --> 00:15:29,840 powerful magnetic fields, trillions of times stronger 444 00:15:29,840 --> 00:15:31,360 than Earth's magnetic field. 445 00:15:31,360 --> 00:15:32,760 Trillions of times stronger. 446 00:15:32,760 --> 00:15:34,680 That's just, I can't even comprehend that. 447 00:15:34,680 --> 00:15:36,840 What makes their magnetic field so strong? 448 00:15:36,840 --> 00:15:38,760 It's thought to be related to the way they form 449 00:15:38,760 --> 00:15:40,640 in supernova explosions. 450 00:15:40,640 --> 00:15:43,040 The rapid rotation and intense pressures 451 00:15:43,040 --> 00:15:45,320 within a newly formed neutron star 452 00:15:45,320 --> 00:15:48,040 can generate these extreme magnetic fields. 453 00:15:48,040 --> 00:15:50,080 So they're like spinning cosmic magnets, 454 00:15:50,080 --> 00:15:52,200 but on a scale that's hard to even imagine. 455 00:15:52,200 --> 00:15:53,360 Exactly. 456 00:15:53,360 --> 00:15:56,000 And these incredibly powerful magnetic fields 457 00:15:56,000 --> 00:15:58,080 can trigger some pretty wild phenomena, 458 00:15:58,080 --> 00:16:01,200 like bursts of high energy X-rays and gamma rays. 459 00:16:01,200 --> 00:16:03,000 So they're not just dense and heavy. 460 00:16:03,000 --> 00:16:05,160 They're also bursting with energy. 461 00:16:05,160 --> 00:16:06,680 I'm sensing a pattern here. 462 00:16:06,680 --> 00:16:08,800 The universe loves extremes. 463 00:16:08,800 --> 00:16:10,040 It certainly does. 464 00:16:10,040 --> 00:16:13,480 And I think we have time for one more stellar oddity. 465 00:16:13,480 --> 00:16:15,360 Wolf-Rayet stars. 466 00:16:15,360 --> 00:16:17,320 These are massive hot stars that are 467 00:16:17,320 --> 00:16:19,520 in the process of losing their outer layers 468 00:16:19,520 --> 00:16:20,840 at an incredible rate. 469 00:16:20,840 --> 00:16:22,200 Losing their outer layers. 470 00:16:22,200 --> 00:16:25,400 Is that similar to what happens when a star becomes a red giant? 471 00:16:25,400 --> 00:16:26,960 It's similar in the sense that material 472 00:16:26,960 --> 00:16:28,600 is being ejected from the star. 473 00:16:28,600 --> 00:16:31,800 But with Wolf-Rayet stars, it's happening much more violently 474 00:16:31,800 --> 00:16:32,720 and rapidly. 475 00:16:32,720 --> 00:16:34,680 They have powerful stellar winds that 476 00:16:34,680 --> 00:16:37,400 are blasting material into space at millions 477 00:16:37,400 --> 00:16:38,560 of kilometers per hour. 478 00:16:38,560 --> 00:16:39,880 Millions of kilometers per hour. 479 00:16:39,880 --> 00:16:41,240 That's like a cosmic hurricane. 480 00:16:41,240 --> 00:16:44,200 What causes these extreme stellar winds? 481 00:16:44,200 --> 00:16:46,920 It's related to their intense radiation pressure. 482 00:16:46,920 --> 00:16:48,600 These stars are so hot and luminous 483 00:16:48,600 --> 00:16:50,080 that the pressure of the radiation 484 00:16:50,080 --> 00:16:52,360 is literally pushing their outer layers away. 485 00:16:52,360 --> 00:16:55,120 So they're like cosmic pressure cookers blasting their contents 486 00:16:55,120 --> 00:16:56,120 out into space. 487 00:16:56,120 --> 00:16:57,720 That's a great analogy. 488 00:16:57,720 --> 00:17:01,280 And this process creates these beautiful and complex nebulae 489 00:17:01,280 --> 00:17:05,360 around Wolf-Rayet stars where the ejected material glows 490 00:17:05,360 --> 00:17:06,840 with brilliant colors. 491 00:17:06,840 --> 00:17:09,240 OK, I think my brain is officially full. 492 00:17:09,240 --> 00:17:11,320 We've covered so much ground today, 493 00:17:11,320 --> 00:17:13,720 from the quiet deaths of white dwarfs 494 00:17:13,720 --> 00:17:16,080 to the explosive supernovae that give birth 495 00:17:16,080 --> 00:17:19,960 to neutron stars and black holes and all the weird and wonderful 496 00:17:19,960 --> 00:17:21,200 stars in between. 497 00:17:21,200 --> 00:17:23,800 It really is a testament to the incredible diversity 498 00:17:23,800 --> 00:17:25,120 of the universe, isn't it? 499 00:17:25,120 --> 00:17:25,920 It is. 500 00:17:25,920 --> 00:17:29,000 I'm starting to realize that every star has a story to tell, 501 00:17:29,000 --> 00:17:31,400 a unique journey through cosmic time. 502 00:17:31,400 --> 00:17:34,120 But with all we've learned today, I have to ask, 503 00:17:34,120 --> 00:17:36,880 are there still unanswered questions about stars, 504 00:17:36,880 --> 00:17:38,840 mysteries that keep astronomers up at night? 505 00:17:38,840 --> 00:17:39,880 Oh, absolutely. 506 00:17:39,880 --> 00:17:41,520 The universe is full of mysteries. 507 00:17:41,520 --> 00:17:44,400 And with every answer, we uncover new questions arise. 508 00:17:44,400 --> 00:17:46,280 But I think that's a story for next time. 509 00:17:46,280 --> 00:17:49,280 You're killing me again with the cliffhangers. 510 00:17:49,280 --> 00:17:52,680 But OK, I guess we have to leave our listeners wanting more. 511 00:17:52,680 --> 00:17:55,000 Don't forget to follow and subscribe to Cosmos 512 00:17:55,000 --> 00:17:57,680 in a Pod and our YouTube channel for the final part 513 00:17:57,680 --> 00:18:01,160 of our deep dives into the fascinating world of stars. 514 00:18:01,160 --> 00:18:04,000 We'll be back soon to explore those lingering mysteries 515 00:18:04,000 --> 00:18:05,600 and see what else we can discover 516 00:18:05,600 --> 00:18:08,320 about these celestial wonders. 517 00:18:08,320 --> 00:18:10,440 Welcome back to Cosmos in a Pod. 518 00:18:10,440 --> 00:18:12,600 I'm ready to delve into those stellar mysteries 519 00:18:12,600 --> 00:18:13,560 you mentioned. 520 00:18:13,560 --> 00:18:15,960 What are the big questions that have astronomers 521 00:18:15,960 --> 00:18:17,040 scratching their heads? 522 00:18:17,040 --> 00:18:19,680 Well, one of the biggest puzzles is understanding the tipping 523 00:18:19,680 --> 00:18:23,000 point between a supernova forming a neutron star 524 00:18:23,000 --> 00:18:25,520 versus collapsing into a black hole. 525 00:18:25,520 --> 00:18:28,440 We know it has to do with mass, but the precise boundary 526 00:18:28,440 --> 00:18:30,000 is still a bit fuzzy. 527 00:18:30,000 --> 00:18:33,000 It's a delicate dance between gravity, nuclear forces, 528 00:18:33,000 --> 00:18:35,680 and the properties of matter under extreme pressure. 529 00:18:35,680 --> 00:18:38,400 So like a cosmic game of tug of war, 530 00:18:38,400 --> 00:18:41,880 which force wins determines the fate of the star's core. 531 00:18:41,880 --> 00:18:43,040 Exactly. 532 00:18:43,040 --> 00:18:45,520 And then there's the whole mystery surrounding black holes 533 00:18:45,520 --> 00:18:46,520 themselves. 534 00:18:46,520 --> 00:18:49,040 We can detect their gravitational influence, 535 00:18:49,040 --> 00:18:51,200 and we're starting to image them indirectly, 536 00:18:51,200 --> 00:18:54,520 but what truly lies at the heart of a black hole? 537 00:18:54,520 --> 00:18:57,200 It's a region where our current understanding of physics 538 00:18:57,200 --> 00:18:58,000 breaks down. 539 00:18:58,000 --> 00:19:00,480 It's like peering into the abyss of the unknown. 540 00:19:00,480 --> 00:19:03,640 I imagine those questions are keeping theoretical physicists 541 00:19:03,640 --> 00:19:04,280 very busy. 542 00:19:04,280 --> 00:19:05,320 They certainly are. 543 00:19:05,320 --> 00:19:07,840 And speaking of mysteries, how about the question 544 00:19:07,840 --> 00:19:10,880 of how planets form around different types of stars? 545 00:19:10,880 --> 00:19:13,800 We've discovered thousands of exoplanets, planets 546 00:19:13,800 --> 00:19:17,040 orbiting other stars, but the process of planet formation 547 00:19:17,040 --> 00:19:19,840 is still shrouded in, well, stardust. 548 00:19:19,840 --> 00:19:21,640 Right, we know it involves gravity pulling together 549 00:19:21,640 --> 00:19:25,280 gas and dust, but the specifics, how those materials clump 550 00:19:25,280 --> 00:19:28,280 together, how planets migrate within a system, 551 00:19:28,280 --> 00:19:30,080 there's so much we're still figuring out. 552 00:19:30,080 --> 00:19:31,580 And it gets even more intriguing when 553 00:19:31,580 --> 00:19:33,840 we consider the diversity of stars themselves. 554 00:19:33,840 --> 00:19:36,120 Can planets form around red dwarfs 555 00:19:36,120 --> 00:19:37,840 with their intense flares? 556 00:19:37,840 --> 00:19:41,120 What about around massive stars that live fast and die young? 557 00:19:41,120 --> 00:19:43,400 Does the type of star influence the types of planets 558 00:19:43,400 --> 00:19:46,400 that can form and ultimately the potential for life? 559 00:19:46,400 --> 00:19:47,880 So many questions. 560 00:19:47,880 --> 00:19:49,480 And speaking of life, that's probably 561 00:19:49,480 --> 00:19:51,360 the biggest mystery of all. 562 00:19:51,360 --> 00:19:53,520 Are we alone in the universe? 563 00:19:53,520 --> 00:19:57,160 Does life exist on other planets orbiting other stars? 564 00:19:57,160 --> 00:19:59,480 It's the ultimate question, isn't it? 565 00:19:59,480 --> 00:20:01,920 And while we haven't found definitive proof yet, 566 00:20:01,920 --> 00:20:04,760 the sheer number of stars and planetary systems out there 567 00:20:04,760 --> 00:20:07,880 makes the possibility incredibly exciting. 568 00:20:07,880 --> 00:20:10,720 Just think, billions of galaxies, 569 00:20:10,720 --> 00:20:12,960 each with billions of stars, many of which 570 00:20:12,960 --> 00:20:15,240 likely have planets, the odds seem 571 00:20:15,240 --> 00:20:17,640 to be in favor of life existing elsewhere. 572 00:20:17,640 --> 00:20:20,540 It's both humbling and awe-inspiring to think about. 573 00:20:20,540 --> 00:20:23,160 And the more we learn about the diversity of stars, 574 00:20:23,160 --> 00:20:25,960 the more we realize how much we still don't know. 575 00:20:25,960 --> 00:20:27,280 That's the beauty of science. 576 00:20:27,280 --> 00:20:29,600 It's a never-ending quest for knowledge. 577 00:20:29,600 --> 00:20:32,320 And the study of stars is a perfect example of that. 578 00:20:32,320 --> 00:20:34,560 It's a journey that takes us from the smallest particles 579 00:20:34,560 --> 00:20:36,640 to the largest structures in the universe. 580 00:20:36,640 --> 00:20:39,320 So from atoms to galaxies, it's all connected. 581 00:20:39,320 --> 00:20:41,200 And what's amazing is that anyone can join 582 00:20:41,200 --> 00:20:42,720 this journey of discovery. 583 00:20:42,720 --> 00:20:45,920 You don't need a fancy telescope or a degree in astrophysics 584 00:20:45,920 --> 00:20:48,040 to appreciate the wonders of the night sky. 585 00:20:48,040 --> 00:20:49,120 Absolutely. 586 00:20:49,120 --> 00:20:52,160 Just looking up at the stars can spark a sense of wonder 587 00:20:52,160 --> 00:20:53,600 and curiosity. 588 00:20:53,600 --> 00:20:57,120 It's a reminder of our place in the vastness of the cosmos. 589 00:20:57,120 --> 00:21:01,000 And it can inspire us to ask questions, to learn more, 590 00:21:01,000 --> 00:21:02,680 and to keep exploring. 591 00:21:02,680 --> 00:21:03,640 Well said. 592 00:21:03,640 --> 00:21:05,240 And speaking of exploring, for those 593 00:21:05,240 --> 00:21:07,880 who want to dive deeper into the world of stars, 594 00:21:07,880 --> 00:21:09,480 what resources would you recommend? 595 00:21:09,480 --> 00:21:12,160 There are so many great places to start. 596 00:21:12,160 --> 00:21:14,040 For getting to know the night sky, 597 00:21:14,040 --> 00:21:17,840 Stellarium is a fantastic free planetarium software 598 00:21:17,840 --> 00:21:20,760 that lets you explore the stars from your computer. 599 00:21:20,760 --> 00:21:21,800 I've heard of that. 600 00:21:21,800 --> 00:21:24,540 It's like having a personal planetarium right on your screen. 601 00:21:24,540 --> 00:21:25,440 Exactly. 602 00:21:25,440 --> 00:21:28,680 And for those who want a deeper dive into the science of stars, 603 00:21:28,680 --> 00:21:32,000 there are classic books like Cosmos by Carl Sagan 604 00:21:32,000 --> 00:21:34,360 and A Brief History of Time by Stephen Hawking. 605 00:21:34,360 --> 00:21:36,000 Ah, yes, the greats. 606 00:21:36,000 --> 00:21:39,080 Their books are truly inspiring, even for non-scientists. 607 00:21:39,080 --> 00:21:40,840 And of course, you can always keep up 608 00:21:40,840 --> 00:21:42,680 with the latest astronomical discoveries 609 00:21:42,680 --> 00:21:44,640 through websites like NASA's website 610 00:21:44,640 --> 00:21:46,880 or by following science news outlets. 611 00:21:46,880 --> 00:21:48,040 Great recommendations. 612 00:21:48,040 --> 00:21:50,400 It's so inspiring to see how much information and knowledge 613 00:21:50,400 --> 00:21:52,920 is out there for anyone who's curious about the universe. 614 00:21:52,920 --> 00:21:55,040 And speaking of inspiration, don't 615 00:21:55,040 --> 00:21:57,800 forget to follow and subscribe to Cosmos in a Pod 616 00:21:57,800 --> 00:22:00,200 and our YouTube channel for more deep dives 617 00:22:00,200 --> 00:22:02,160 into the wonders of the cosmos. 618 00:22:02,160 --> 00:22:04,160 We have lots more exciting episodes coming up, 619 00:22:04,160 --> 00:22:06,600 covering everything from black holes to the search 620 00:22:06,600 --> 00:22:08,280 for extraterrestrial life. 621 00:22:08,280 --> 00:22:09,040 That's right. 622 00:22:09,040 --> 00:22:12,120 We'll be exploring the mysteries of dark matter, the birth 623 00:22:12,120 --> 00:22:14,960 and death of galaxies, and so much more. 624 00:22:14,960 --> 00:22:18,400 So join us as we continue our exploration of the universe. 625 00:22:18,400 --> 00:22:20,600 This deep dive into the universe of stars 626 00:22:20,600 --> 00:22:22,960 has been absolutely fascinating. 627 00:22:22,960 --> 00:22:25,280 From their formation to their dramatic deaths, 628 00:22:25,280 --> 00:22:28,040 stars drive the evolution of galaxies, 629 00:22:28,040 --> 00:22:31,320 create the elements that make up our world, and inspire us 630 00:22:31,320 --> 00:22:33,480 to contemplate our place in the cosmos. 631 00:22:33,480 --> 00:22:35,880 It's a reminder that we are all connected to the universe 632 00:22:35,880 --> 00:22:37,040 in profound ways. 633 00:22:37,040 --> 00:22:39,160 We are, after all, stardust. 634 00:22:39,160 --> 00:22:40,800 A beautiful thought to end on. 635 00:22:40,800 --> 00:22:43,280 Thank you for joining us on this cosmic adventure. 636 00:22:43,280 --> 00:22:45,680 Until next time, keep looking up and keep exploring 637 00:22:45,680 --> 00:22:58,440 the wonders of the universe.