Pod Insights StarTalk Podcast The Life and Death of Stars with Jackie Faherty About this episode Are we really made of stardust? On this episode, Neil deGrasse Tyson and comic co-host Negin Farsad explore the life – and death – of stars with astrophysicist Jackie Faherty, PhD.
Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:01 Neil deGrasse Tyson? Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.
0:14 Neil deGrasse Tyson? This is StarTalk. I'm your host Neil deGrasse Tyson, your personal astrophysicist. And this is a Cosmic Queries edition on the birth, life, and death of stars.
0:28 Neil deGrasse Tyson? Didn't know we know all about them, did you? And who do I have as my co-host today? Negin Farsad. Negin, welcome back to StarTalk.
0:36 Negin Farsad? Oh my gosh, I'm so excited about today's topic. I don't understand any of it.
0:40 Neil deGrasse Tyson? Well, you're in the right place at the right time. And you, you're a comedian and you're a host of Fake the Nation, which I was recently a guest on. I was delighted. Thanks for having me.
0:49 Negin Farsad? You were so great. People should listen to that episode.
0:53 Neil deGrasse Tyson? Oh, well, thank you. Yeah, yeah. And you're also author of the book, "How to Make White People Laugh." Now, I laughed just reading that title. Is that allowed?
1:03 Negin Farsad? And that's, the entire book is just the title. That's it. And there's no, it's actually just a notebook where you can write your own thoughts.
1:11 Neil deGrasse Tyson? I didn't know if the, like, the laugh police, "No, you're not white. You can't laugh at that." You know, it's the thing. So while I, as an astrophysicist, have some background in the birth, life, and death of stars, it does not compare to who we brought in as a special guest, a friend and colleague, Jackie Farady. Jackie, welcome.
1:32 Speaker 02 Hi, everybody.
1:34 Neil deGrasse Tyson? All right, all right. Jackie, like, lives in the lives of stars. And she knows where they come and where they're going, where they've been. And I finally got your full title here, Jackie. Senior Scientist and Senior Education Manager at the American Museum of Natural History. And you're also a part of our Department of Astrophysics as an associate there. And you're also an astronomy professor for outlier.org. So what is that?
2:01 Speaker 02 Yeah, outlier.org is this company that was started by the co-founders of MasterClass.
2:08 Neil deGrasse Tyson? Oh, okay.
2:08 Speaker 02 And they, yeah, which you did a MasterClass, right?
2:11 Neil deGrasse Tyson? I did a MasterClass, yeah, yeah. But they're good people, all good people, yeah.
2:14 Speaker 02 So you know that they put, like, they put production value as very important in the course creation, but they also, like, they don't skim on content. So they contacted me and a couple other astronomers to put together an introduction to astronomy class that would bring all the things that you need to know about the universe at the 101 level, you know?
2:37 Neil deGrasse Tyson? Yeah, astro 101, excellent, excellent.
2:39 Speaker 02 Yeah. Critical to this, though, is that they came to the Hayden Planetarium before they even talked to me about this, because they loved our visualization space there.
2:51 Neil deGrasse Tyson? And you have access to data that helps inform so many of our visualizations in the shows that we produce. So you're like a key cog in that turning wheel of bringing the universe down to Earth.
3:07 Neil deGrasse Tyson? So Jackie, let me just lead off with a question for you, just to get, so we're all on the same page. And Negin, since she doesn't know anything, we got to make sure she joins the page that you and I are on, all right? If stars live millions and billions of years, and we look up at the night sky and just get a snapshot of them, what right do you have to possibly claim that you know how they're born?
3:30 Speaker 02 Yeah, it's, uh, it's pretty offensive that we decide we know how they're born, right?
3:35 Neil deGrasse Tyson? That's just audacious. That's like taking a snapshot of Negin and saying, Negin, we know when and where you were born, and when you're gonna die, and where you're gonna die, and, but you just have a snapshot of her in this one moment.
3:45 Negin Farsad? It's like the worst retroactive gender reveal party.
3:52 Speaker 02 Well, right, so, so the thing with stars, which I think is, it's really fascinating, is sometimes we project human emotion onto them. So we talk about the life of stars, as if they live somehow, and that they die, and that this is sad. But there's really no life or death, it's just sort of morphing from one kind of thing into another. And this is what stars do. And when we look up at the nighttime sky, we look for signatures in the vast numbers that we now know are out there that tell us that this one is recently in the stellar form that we see it,
4:32 Speaker 02 or this one's heading out of looking like the stars as we know and love them, and it's gonna start to look like something a little bit different. So, we do know a lot. We also know very little, but we do know a lot.
4:47 Neil deGrasse Tyson? That's a disclaimer. We know so much, but really, we don't know much at all. But we know so much.
4:53 Negin Farsad? This makes you sound a little bit like a lawyer,
4:58 Negin Farsad? and not a scientist when you say stuff like that.
5:01 Speaker 02 You have to put a clause on everything, because you can't have people thinking that we know everything that there is, because then there'd be no reason for us to continually say, "They're so mysterious, the cosmos are so mysterious." And Vera Rubin, actually, I think she famously said something like, "We're like kindergartners right now, humans that are looking up into the sky and trying to figure stuff out. No one should say we're advanced when it comes to everything that we know and understand. There's so much to know and understand and learn. But we do know quite a bit about stars."
5:33 Neil deGrasse Tyson? Well, you can't just blow by Vera Rubin without a little bit of bio. So, she was one of our more senior members of our community, died a few years, a couple of years ago. And she discovered dark matter in galaxies. So, that sort of brought dark matter home in a way that was like, whoa, this stuff is not just exotic at the edges of the universe. It's in our face. And we just named a telescope after her, Jackie, right?
5:55 Speaker 02 That's right, yep.
5:57 Neil deGrasse Tyson? The Large Synoptic Survey Telescope, which no one wanted to pronounce, and we said, "It's time to just fix that up." And so, now it's the Vera Rubin Telescope. She's one of our heroes in our field. So, go on.
6:08 Speaker 02 Absolutely, yeah. Yeah, and I actually overlapped with Vera when I was a postdoctoral fellow, the phase you get to when you have a PhD and you're in between faculty or whatever next stage you get into. And I was at the Carnegie Institution for Science. In Washington DC and that's where Vera did a significant amount of her career and she was a huge advocate for women in science. I mean, massive advocate for women in science. So she was, it was amazing to be in the same department that she was in.
6:40 Negin Farsad? By the way, Jackie, who among us hasn't been at the Carnegie Institute for Science as a postdoctoral fellow? I'm just, you know, talking to the choir here.
6:49 Neil deGrasse Tyson? That's just a thing. It's just a thing. Although Negin, did I hear Jackie say that being a postdoc is what you are before you have your faculties? Is that what she said?
7:01 Speaker 02 Did I say that?
7:03 Neil deGrasse Tyson? I thought you said-
7:04 Negin Farsad? Before you have the touch and feel you-
7:08 Neil deGrasse Tyson? Before you have your faculties. Your faculties are still being home. So that's great. So we solicited questions from our Patreon members. So apparently we're playing hardball now. You want to get a question done in on this, you got to sort of get in the Patreon circle. So Negin, you collected them? I haven't seen them before. I think Jackie knows the topic, but I don't know that she's seen them either. So we're hitting at this cold. So let's do it.
7:34 Negin Farsad? Okay, you guys are up for some treats here. From Cameron Bishop, we have this question. My cosmic query is about life after the death of stars, specifically for any planets unfortunate enough to be in orbit. How are their orbits affected and could life-
7:50 Neil deGrasse Tyson? Oh, I love that. He's worried about the family.
7:53 Negin Farsad? Yeah.
7:54 Neil deGrasse Tyson? He's worried about the family.
7:55 Speaker 02 So true. Yeah, I know. The idea that you could exist around a star that once was. And I actually think about this question a lot nowadays for a number of reasons. But we are finding planets around dead stars, around, see there I go again. I just said that we always project these emotions on stars, but stars that have morphed into their new counterpart, so white dwarfs, these end products of stars like our sun or neutron stars, which are higher mass than our sun would be. And you can find worlds around these
8:34 Speaker 02 things, like planets that have either survived, they've survived whatever this thing was that was like to have your star basically- Lose its ability to be a nice core hydrogen burning thing that provides you nice sunshine and light and it fades into this other other phase. So planets can survive this. So we should talk about our own solar system because we have eight worlds, planets that we call in our solar system. Pluto's out there as a dwarf planet. Neil, I know that's your favorite topic.
9:12 Neil deGrasse Tyson? You know, I'm biting my tongue.
9:14 Speaker 02 I know, I see you are. I can see you. I was avoiding your tongue. Right.
9:17 Negin Farsad? A lot of restraint.
9:19 Neil deGrasse Tyson? A lot of restraint. Thank you for noticing, Megan.
9:22 Speaker 02 I noticed that. But so, you know, when our sun starts to lose its hydrogen and burn out, it's going to expand and it's going to absorb the inner solar system. Mercury, Venus, Earth probably, and maybe out to Mars is going to get engulfed in the sun.
9:42 Negin Farsad? This sounds like a spinoff series to The Biggest Loser. Like a really galaxy-wide spinoff series.
9:51 Speaker 02 Yeah, yeah, yeah. Well, so you could feel...
9:55 Neil deGrasse Tyson? Wait, wait, wait. So Jackie, what you're saying is in death or in its transition to not fusing hydrogen in the core, it will eat its children. That's what you're saying?
10:07 Speaker 02 You could say it like that. I think that...
10:09 Neil deGrasse Tyson? As long as we're going to anthropomorphize, it dies and right while it's dying, it eats and vaporizes its children.
10:16 Speaker 02 Yep, yep. And there is evidence, at least some observational evidence, that this does happen, that planets do get gobbled up during this process. There's objects that we look at, the white dwarfs that we are, white dwarfs is these evolved states of stars like our sun after they've run out of their hydrogen. They, we found they've got signatures of basically pulling in the last of this material that might have come from a rocky world like the earth. And so we do see signatures of that planet on the white dwarf. It's a really cool new thing.
10:50 Neil deGrasse Tyson? What? You're saying it's like it... You're saying it's like it's got food on its lips that it didn't wipe away. It still has evidence of eating, of eating the planets still in its mouth.
11:03 Speaker 02 Nice. Yes, yes.
11:04 Negin Farsad? It's like a lot like my toddler. All day long.
11:09 Neil deGrasse Tyson? You know exactly what they've been eating all day. The ice cream drip, the candy cane, right, all right.
11:17 Negin Farsad? By the way, I just want to point out, are we, are we allowed to say white dwarfs? I just want to make sure we don't get cancelled here.
11:26 Neil deGrasse Tyson? Yeah, where the black dwarf?
11:29 Speaker 02 We can say that.
11:30 Neil deGrasse Tyson? You think we can say that? All right.
11:32 Speaker 02 Yeah, yeah, but white dwarfs, so planets around stars that have evolved is a thing. I don't think you want to live around it necessarily. Oh, but a cool thing in our own solar system, when it does happen that our sun ends up doing its thing and bloating out, you called it, what did you call it? The, um, the Biggest Loser aspect of it.
11:53 Negin Farsad? Yeah, a spin off series of The Biggest Loser.
11:57 Speaker 02 So when that happens, it's going to get hotter, farther away from Earth. So Pluto might thaw down and be an interesting world to look at, uh, at that stage.
12:09 Neil deGrasse Tyson? I ain't moving to Pluto. Don't, don't, don't try to get me to. That ain't happening. That ain't happening. I'm just saying. I'm just saying too. All right. So what it means, Jackie, is that if we figure out how to, as a species, outlive the sun, we need to find another star system to travel to. And I would hope in five billion years, we have enough space travel to enable that.
12:32 Speaker 02 Well, you know, we could maybe stay in our own solar system, Neil, but we'd have to stay within, because we've got a lot of interesting planetary bodies outside of the planets. There's the moons in the outer solar system that are intriguing.
12:44 Neil deGrasse Tyson? So we planet hop our way away from the sun as the sun is dying.
12:48 Speaker 02 We keep thinking about our own solar system before we decide, like, let's kick it from this side of the, you know, Brian Arm of the galaxy and head out.
12:57 Neil deGrasse Tyson? All right.
12:58 Speaker 02 Just a suggestion.
12:59 Neil deGrasse Tyson? All right, keep it coming, McGee.
13:01 Negin Farsad? All right, from Ben Sellers. He writes, Neil and others have said the beautiful words that we are all made of stardust. By the way, Ben, if you really mean it, you should get the tattoo. Okay. He writes, atoms forged within stars that later spread through the universe after star dies. But how do we know that the atoms in our bodies are from stars? Is there a stolar barcode on my nitrogen atoms?
13:25 Neil deGrasse Tyson? I like that.
13:26 Negin Farsad? Stellar zip code for my oxygen. Couldn't these elements have been generated in the Big Bang or during other processes?
13:33 Neil deGrasse Tyson? Yeah, Jackie, what's up?
13:34 Speaker 02 Yeah, I love this question. There is something that is kind of new into pop culture, or even pop science culture, I would say. It's called the astronomer's periodic table. Have you seen this, Neil?
13:47 Neil deGrasse Tyson? No, I haven't, I haven't.
13:48 Speaker 02 It's really cool. So astronomer named Jennifer Johnson at Ohio State was getting so frustrated with this concept that gets thrown around that all heavier elements formed through supernovas. So that you need supernovas that are to form anything that's heavier than hydrogen, I can say. So, you know, hydrogen, helium, we think come from the Big Bang. That, that, that one, I hope Ben wasn't necessarily disputing. It's the higher elements, and you get some lithium from the Big Bang, too. But it takes higher level explosions to get the rest of the stuff. And Jennifer Johnson is getting frustrated with it.
14:30 Speaker 02 So she created, on a bar napkin one day, this, this diagram of the periodic table as shown through what processes developed those elements. And then it got turned into a graphic that gets used out. So I suggest anyone look this up because it's an awesome, beautiful graphic. If you want to know where gold comes from, where astronomers think gold comes from, or silver, or copper, you have to look at this diagram and it'll show you.
15:01 Speaker 02 What we think the physical process was that led to that element emerging onto your periodic table.
15:08 Neil deGrasse Tyson? So Jackie, you're saying when I was in high school and my chemistry teacher said, "Here are all these elements on the periodic table," and I asked him, "Where did they come from?" He said, "Oh, we dig them out of the earth." I was unsatisfied with that answer. It would be a few more years when I'd learned that this stuff came from the universe. If we had that periodic table next to the regular one, I would have been totally satisfied from early on in life. That's what you're telling me.
15:31 Speaker 02 I think we should use this periodic table in those exact kind of classes because even in the, if I could get on a little soapbox about New York State's curriculum.
15:40 Negin Farsad? Uh-oh.
15:41 Neil deGrasse Tyson? Uh-oh, here it comes.
15:42 Speaker 02 I know. Well, we have this amazing program at the American Museum of Natural History. It's a master's program that we teach teachers how to teach science and they come out and become earth science teachers. And one of the core elements in the New York State curriculum is elements higher than iron on the periodic table come from supernova. And I'm like, "No, no, no, no, no. We know more now." We should be able to say like, "There's neutron, neutron star mergers." There's the death of low-mass stars, which ends up producing quite a bit of the material that makes up all of us. And then there's cosmic ray fission that you can see. There's a couple of processes, and if you saw it on the periodic table,
16:25 Speaker 02 you might start to feel a little bit more connected to stellar processes, to stars, to the kinds of stars that are out there. So I suggest looking at the astronomer's periodic table.
16:35 Negin Farsad? By the way, I love it.
16:36 Neil deGrasse Tyson? We're all connected, is what you're saying, in more ways than previously known. I like that.
16:41 Speaker 02 Yes.
16:42 Negin Farsad? I love, by the way, I was gonna say that I love that this scientist drew, started drawing this periodic table on a bar napkin, which indicates she got drunk and started making a new periodic table where most people get drunk and just draw penises on a bar napkin. So it's a little different. It's just a little different.
17:01 Neil deGrasse Tyson? Yes, or some people drunk-text people. And if you're a quality scientist, you drunk and invent new ways of understanding the universe.
17:09 Negin Farsad? She probably drunk, yeah. She drunk-text new elements is what she's doing.
17:13 Speaker 02 I want to make sure that I qualify it too, though, because I may have inserted that anecdotal note. I'm not positive it was a bar.
17:20 Negin Farsad? No, no, no. It was a bar napkin. It was a bar napkin.
17:23 Neil deGrasse Tyson? Just leave it. It's good. Let that one stick. We gotta take a quick break. When we come back, more Cosmic Queries with Jackie Farady. We're talking about the birth, life, and death of stars.
17:46 Speaker 03 I'm Joel Cherico, and I make pottery. You can see my pottery on my website, cosmicmugs.com. Cosmic Mugs, art that lets you taste the universe every day. And I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.
18:13 Neil deGrasse Tyson? We're back, Cosmic Queries, with my co-host, Negin Farsad. Negin, always good to have you on StarTalk.
18:19 Negin Farsad? Oh, I love being on.
18:20 Neil deGrasse Tyson? I want more of you on StarTalk, so we gotta work that out. And this is Cosmic Queries, always a popular variant on the StarTalk model. And today, the topic is the birth, life, and death of stars. And we've got my friend and colleague Jackie Farady from the American Museum of Natural History. It's what she does, it's what she breathes. She thinks about stars day and night. Jackie, all right. All right, let's do this. So Negin, give me some more questions.
18:49 Negin Farsad? Okay. Woody asks, "Does a star becoming a black hole count as star death? Seems like more of an evolution. But if that's true, and Jupiter is a failed star, does that make stars failed black holes?"
19:02 Neil deGrasse Tyson? Ooh!
19:04 Negin Farsad? I know.
19:04 Neil deGrasse Tyson? Snap!
19:05 Negin Farsad? He got real hot there.
19:07 Neil deGrasse Tyson? He got, he got all philosophical on you, Jackie. Yeah, dig, dig out of that one, Jackie. See what you do with that.
19:12 Speaker 02 I mean, there's a couple of triggers in there for me when it comes to words that one, because as, as, as, I'll start with the biggest one, which Neil knows that my, my super expertise in astronomy is on these things called brown dwarfs. So, we talked about white dwarfs. White dwarfs are stars that have evolved off from like our, kind of our sun's mass. Brown dwarfs are objects that exist in between stars and planets. Now, what people like to call them because of...
19:49 Speaker 02 Various reasons which I could get into is failed stars. Because they don't have enough mass to get their core hot enough so that they can burn and to have a nuclear engine like the sun does. So they call them failed stars. But does anybody want failure in the title of what they are? Let's just all say no, right?
20:09 Negin Farsad? We don't, we don't. Advocate for them. Thank you, Jackie.
20:12 Speaker 02 You're welcome.
20:13 Neil deGrasse Tyson? They have feelings too. Right, okay.
20:16 Speaker 02 Yeah, there's more on this feeling thing. But, you know, they're, they are not failures in any way, shape, or form. I sometimes call them overexcited planets because that, you know, the word planet, everybody loves. And so that's nice. But Jupiter is certainly not a failure at what it is. And I would not call it in any way a failed star, number one, because that would also imply that it's a brown dwarf from some rules that people are putting in. And Jupiter's not big enough. You have to be around 13 times the mass of Jupiter before you can actually get some heavy hydrogen burning and start entering a category, which we sometimes call the boundary of brown dwarfs. So Jupiter's totally good with where it is. And I'm sorry to pick on Ben, was it?
21:01 Negin Farsad? Woody.
21:03 Speaker 02 Woody, Woody, I'm sorry, Woody. This feels like I'm picking on you, but sometimes it happens. And then as far as stars being failed black holes, well, I mean, black holes aren't stars either. Black holes are the evolved take on stars. And some stars will become black holes if they have a high enough mass. But most stars are not massive enough to become that. You've got to be a really massive star. And those are actually the rarest kinds of stars that we have. High mass stars, the ones that are eight and more, 10, 15, 20 times the mass of our sun. Those are the ones that start entering a territory where they may end up
21:43 Speaker 02 be having enough mass to go supernova and then become a black hole. Those stars now would become black holes. So it's a different category. Not to pick on Woody too much, but let's not, let's remove failure from our thinking. Let's go positive.
22:00 Neil deGrasse Tyson? We could also buy that token, Jackie. We could say that the sun is a failed Jupiter.
22:06 Speaker 02 Yeah, if you wanted to reverse the negativity, we could.
22:09 Neil deGrasse Tyson? Yeah, let's do that. Just to balance it out over time. And then we can neutralize it in 10 years. How about that?
22:15 Speaker 02 Yeah. If Jupiter wanted to throw shade on the sun, it would call the sun a failure.
22:21 Neil deGrasse Tyson? Yeah, there you go.
22:22 Negin Farsad? Folks, Jackie is handing out participation trophies, basically, to all of the stars and planets. I think that's what's happening here.
22:30 Neil deGrasse Tyson? And to be explicit there, if Jupiter eclipses the sun for another civilization that's looking at the discovery of planets, then Jupiter is literally throwing shade on the sun.
22:42 Speaker 02 That's good. That's pretty good, Neil.
22:44 Neil deGrasse Tyson? Yeah.
22:45 Negin Farsad? Well done, well done.
22:47 Neil deGrasse Tyson? All right, so, Bagheen, keep going.
22:50 Negin Farsad? Okay, Jesse de La Rosa asks, "Once a star has entered its death sequence, how long do they take? Also, have there been any stars that have come back into life?" Or have come back to life?
23:02 Neil deGrasse Tyson? I like that. I like that.
23:04 Speaker 02 Zombie.
23:05 Neil deGrasse Tyson? Zombie stars, yeah.
23:07 Speaker 02 That's the thing. Neil, you might remember, we were at a science coffee recently, and we were talking about zombies.
23:12 Neil deGrasse Tyson? Well, tell people what science coffee is, just so it's not like we're studying coffee.
23:15 Speaker 02 Oh, yes.
23:16 Neil deGrasse Tyson? Right.
23:16 Speaker 02 Right. So, once a week, in our Department of Astrophysics at AM&H, we all get together, and we review the papers that have come out over the week. So, every day, astronomers are posting their peer-reviewed, "Here it is. This is what my result is." It's gone through a process where other experts in the field have put their checkmark on it. I'm putting it out in the literature for everybody to reference, to read, to think about, to comment on, to contradict. And so that happens every day. You probably get somewhere between 30 and 70 papers that'll come out. I would say 70 is a big day, but sometimes that does
23:56 Speaker 02 happen. And so, at the end of the week, hopefully, all of us have at least looked at some of them. And we get together and we start discussing, like, okay, so who says what, and what do we think? And so that happens on Fridays. And we used to do it all in person, where we would have coffee and cookies, and it's nice, it's jovial. But we don't, we do it on Zoom now, so we should call it something else. I don't know what, but.
24:22 Neil deGrasse Tyson? B.C., before COVID.
24:24 Speaker 02 Yeah. In the before-COVID times, yeah. But, right, so the question is about, I've already forgotten what it was.
24:33 Neil deGrasse Tyson? Sorry, I distracted you, sorry.
24:36 Negin Farsad? How long does the death sequence take? And do they ever come back to life?
24:42 Speaker 02 Right, okay, so the death sequence and um, this, I think this is an interesting thing to think about. It really depends on your mass, how massive you are. So for low mass stars versus the highest mass stars, it's gonna be totally different values that I could give you. For the lowest mass stars that exist, which, by the way, they are the most populous stars in the galaxy. They're everywhere. And if you wanna know how good star formation is at making a kind of star, it's really good at the lowest mass stars. But those, the lifetimes of the lowest mass kinds of stars, they actually live for longer than the age of the, of the universe right now.
25:27 Speaker 02 They can live for a hundred billion years, which means that every low mass star that was ever born is still around. It hasn't started its death cycle yet. I like that phrasing. Um, high mass stars, on the other end of it, they, they're, they live wild and they die real fast. So they go very quickly through all of their fuel. There's a good analogy here somewhere of the kinds of people that might be low mass stars.
26:00 Speaker 02 But I don't have it. The highest mass stars are, um, they, they will go, they only live for a hundred million years. The lowest mass things, like I said, they'll go for a hundred billion years. Can you believe this? This is insane. So they're everywhere and they're beacons of the history of the galaxy. Um, and now, once they do start going through the phase, like our sun, for instance, is about four and a half billion years old, as by our metrics of measuring it. And we think it's got enough hydrogen, enough fuel, to go for another four and a half billion years or so before. It's out and it's a red giant and it blows off its outer layers and then the whole
26:45 Speaker 02 chaos ensues in the solar system. But there'll be a lot happening in, say, a billion years. It's gonna get super hot in our area of the solar system because the sun is losing a bit of mass. It's got a nice solar wind, it's losing a bit of mass, temperature's getting a little bit hotter. And so because of that, conditions will change in the solar system. It's not necessarily the death cycle, but you could say it's the aging process. It's the aging process for stars.
27:15 Neil deGrasse Tyson? All right, so how much of a star's life does it spend dying? What fraction of its life? So if I live 100 billion years, now I'm ready to die, how quickly do I die?
27:27 Speaker 02 So in astronomy, we define your solid, you're a star, you're not dying, as the time that you spend what we call the main sequence. The main sequence. The time when you're stably burning hydrogen and you've got a core that's nicely balanced where the pressure that's coming from the core is balanced by gravity trying to contract you. So that's a stable situation and that's what we technically call the main.
28:00 Neil deGrasse Tyson? So you're referring to astrophysically stable as distinct from emotionally stable? Because that would be a different issue.
28:06 Speaker 02 Oh, yeah. The emotionally stable star. You could probably make a really good comic out of like the stability strip for stars. There is an instability strip, you know? I'm not making this up. Stars live on their main sequence and when they start to go off, they go on an instability strip where they are wobbling around, they're unstable because gravity and the pressure coming from their cores is trying to find a new balance.
28:34 Negin Farsad? And because they need more sleep, you know? And they need to be hydrated.
28:38 Speaker 02 There you go.
28:39 Negin Farsad? It's like they need to meet some of their basic self-care needs.
28:41 Neil deGrasse Tyson? There it is.
28:42 Speaker 02 Yes, all of that. I would agree. I'm in a complete agreement with this. Even though I said I don't think we should have more, uh, give emotions to these, but it's, it, sometimes it helps. They need, they need loving environments. They need to be in an area where they feel good. You don't want to be in a highly irradiated area. That's not good for you. That's very unhealthy.
29:06 Neil deGrasse Tyson? Or in a place where there are too many other objects that could do a gravitational, uh, slingshot around you and mess with your orbital stability. That, that's bad too.
29:14 Speaker 02 Exactly. Exactly. Do you want to live, so some of this could be, um, like urban life? If you want to live at the center of the galaxy, that is not a solid, healthy place for most stars. Let's just all be honest. There's too much radiation.
29:31 Negin Farsad? As someone who lives in Manhattan, I take issue with that characterization.
29:38 Neil deGrasse Tyson? It just means you're irradiated, Nadine. That's all that means.
29:41 Negin Farsad? Irradiated is the most fun way.
29:43 Neil deGrasse Tyson? So tell me about zombies now. Tell me about zombies. So that was the other half of the question.
29:46 Negin Farsad? Oh, right.
29:47 Speaker 02 Yeah. So can a star come back to life after it's already passed through a, um, its evolved state? And so the answer to that is yes, sort of. So it depends on what you mean by like what stage it might be in. And the thing that we were talking about at Science Coffee was these zombie neutron stars. So these evolved versions of stars. So they've already passed through. Like, can you become a star again? That question I don't have an answer to. I don't think that that's an easy thing to come back from. You can get stripped down. So imagine yourself as a star and I'm going to give you a companion that's going to be really close to you. And that companion is just going to start yanking
30:32 Speaker 02 on all of your material. So that you're in a companion scenario where one object is pulling material from the other, getting bigger. One's getting bigger, the other's getting skinnier. And so the bigger star, or the star that's pulling material from you. Will eat you and become a really interesting kind of object, which we think leads to eventually it might lead to a supernova explosion. But then that other object, maybe you strip it down to where it goes from being a star to being a brown dwarf, where all of a sudden, the core of it can't process material the same way. It can't get hot enough to burn like a star.
31:12 Neil deGrasse Tyson? So you shut it off?
31:13 Speaker 02 It becomes...
31:14 Neil deGrasse Tyson? You just shut off its process? Alright, alright.
31:16 Speaker 02 And then you can keep going and strip it down to it's basically a planet, to it's like Jupiter, and it's, it could even go down all the way to some rocky semblance of an object. So there is that that can happen. And then it's possible that a companion or material that gets dumped onto you can trigger you to have a new sort of sense of an object. So neutron stars might have this with a companion that triggers them back into life where they start pulsating, or they get a bunch of material that ends up looking like they've come back to life. They get, they become bright once again. Companions can do that for you. No object is going to naturally come back into some sort of stellar state, though.
31:58 Speaker 02 It needs to have some sort of outside material or outside mechanism that ends up...
32:02 Neil deGrasse Tyson? So to be a zombie, you need to have a friend?
32:03 Speaker 02 Yeah. That's a good way of putting it, Neil.
32:08 Neil deGrasse Tyson? Just to help you out of the grave.
32:09 Negin Farsad? This is not track with the way The Walking Dead works, by the way.
32:14 Neil deGrasse Tyson? I think it's an unwritten episode of The Walking Dead.
32:17 Negin Farsad? Yeah, it's like a nice capsule episode. I like that. Let's send that idea to them, Neil.
32:24 Neil deGrasse Tyson? Alright, we gotta take another break. When we come back, the third and final segment of Cosmic Queries, the birth, life, and death of star.
32:42 Speaker 04 Hey, it's time for a Patreon shout out to the following Patreon patrons. TheWarZone12, 1/4/9, that is the name that's given, and Michael Borger. Guys, thank you so much for your support and for your very amusing names. And anybody else who would like their very own Patreon shout out, please go to patreon.com/stargtorkradio and support us.
33:19 Neil deGrasse Tyson? We're back. StarTalk, Cosmic Queries, the birth of life and death of stars. My co-host, Nagin Farzad. Nagin, love having you as my co-host. And what is your Twitter handle, for everybody to know?
33:30 Negin Farsad? Oh, it's @NaginFarzad, N-E-G-I-N-F-A-R-S-A-D.
33:35 Neil deGrasse Tyson? Okay, that's your name, right?
33:41 Negin Farsad? It would have been easier if I just said, "It's my name."
33:43 Neil deGrasse Tyson? That's right. Okay, you got that one done?
33:48 Neil deGrasse Tyson? And Jackie, you're also active on social media, so how should people find you?
33:52 Speaker 02 I'm on Twitter, Twitter and Instagram, and my Twitter's @JFarady. That one's easy, I feel like.
33:59 Neil deGrasse Tyson? Yeah, F-A-H-E-R-T-Y.
34:01 Speaker 02 Should be easy. And then Instagram, it's @JFarady17.
34:05 Neil deGrasse Tyson? Ooh, there were 16 other J-Faradys?
34:08 Speaker 02 I don't know if there was, I just liked the number 17. So as soon as one is taken, I'm like... And then I automatically just jump to 17.
34:16 Neil deGrasse Tyson? I got you. Very cool. All right, so we have questions. This is our third and final segment. And Negin, let's see how many we can squeeze in. Go for it.
34:24 Negin Farsad? Okay. Parker Graham asks, "When a star begins to die and starts its expanding phase, can that phase be long enough for it to be possible for far-orbiting planets to become inhabitable and even possibly create new life?"
34:42 Speaker 02 Yeah.
34:42 Neil deGrasse Tyson? So I guess, Jackie, it's not, "Does it reach the right temperature?" But will that last long enough for biological evolution to do its thing? Which we know takes time.
34:51 Speaker 02 Yeah, so I think that there's two points to this. Number one is that during the death cycle of stars, I'll just start calling it that, what happens is the habitable zone around the star does start moving. This is part of why we're gonna have such a problem around the sun in about a billion years, because by that time, the habitable zone, where liquid water doesn't have a... Liquid water is the definition of the habitable zone, where it can bubble on the surface. And so unless you're in that habitable zone, water's gonna be an issue. So for these giant stars.
35:25 Neil deGrasse Tyson? Liquid water, liquid water is gonna be an issue.
35:27 Speaker 02 Liquid water is gonna be an issue, on the surface, I should say, too. That's very important, because you can have water deep down, under a crust of ice or something. You can, you can have water. But liquid water bubbling on the surface is one of our metrics for defining, like, that might be a good place to look for, for life. So the habitable zone, that area moves around a lot as that star is moving through the phase. And so, wh- how long you need for biological life to show up? I- it has to get there somehow. If your world already has an ocean. So let's say, in our own solar system as an example, when our sun starts to bloat out,
36:07 Speaker 02 and some of the outer objects in our solar system, there's awesome moons like Enceladus and Europa, and um, even Pluto. I know Neil doesn't love Pluto discussions at some level, when it's talking about it as a planet, but that's why I like to call things worlds. And the habitable zone will start stretching away from our sun. And there are already created objects, which may already have a lot of the ingredients that you need for organic life. And so, I would, I would not count it out as impossible, but you do need some of the ingredients there already.
36:48 Speaker 02 So, the prescription is have something there, be ready, and maybe the habitable zone will show up at your door, uh, and you'll melt down and life could emerge.
36:59 Neil deGrasse Tyson? Mm.
37:00 Speaker 02 Fluently.
37:01 Neil deGrasse Tyson? Alright.
37:02 Speaker 02 Yeah.
37:03 Neil deGrasse Tyson? I like it. Alright, keep it coming, Negin.
37:04 Negin Farsad? Okay, uh, Jared Sim says, uh, hello, Dr. Tyson, Dr. Faraday, and of course, the hilarious Negin. I included that part. It was a compliment to me in there.
37:13 Speaker 02 Jared asks, what would happen?
37:15 Neil deGrasse Tyson? Jared's favorite comedian ever in the whole universe. Right, right, that was in parentheses.
37:20 Speaker 02 What would happen if you could split a star right in half? Would it come back together from gravity and other binding forces? Or is there a sufficient distance where they would be two separate pieces? Lifespan, question mark?
37:34 Neil deGrasse Tyson? Wow, this sounds like a science fiction, something that the Death Star weapon from Star Wars might want to try to do. We're done killing planets, now let's cut a star in half.
37:44 Speaker 02 Yeah, yeah, I will say, a lot of these questions are a little dark and a little dangerous, like I don't know what the, what people were thinking when they were submitting them, but there's definitely a little bit of darkness here. Could you split it, like take a knife, like some knife and split it down the middle?
38:04 Neil deGrasse Tyson? Just a laser, just laser, cut the thing in half, and then what happens next?
38:08 Speaker 02 My immediate reaction to that is absolutely not, but that's in part because you'd have to be so, this is so science fiction, because you'd have to be so swift in order to figure out how to get certain physical properties to not immediately react, so that you could get a scissor through it. I mean, a better answer maybe is to a question that this person isn't asking, but I want to answer, and I think it does help here, is when you hit one star with another star, what happens? Because that starts with two halves, and number one, how often does it happen? And that answer is, stars don't collide very often, but it can happen.
38:53 Speaker 02 They swirl around each other, because gravity is something that's not that interested in seeing the two objects smash into each other, they have to overcome that. Then when they do, they can coalesce into a new thing. To get two halves is...
39:10 Speaker 02 Very science fiction in my, in my quick reaction to that.
39:14 Neil deGrasse Tyson? But I'm imagining, but listen, but if, if it is science fiction and you have these big old hands, let's say that it grabs two sides of the star and pulls it apart. There's a distance you could pull them apart where I think they would just coalesce into two separate stars, each with half the mass that the previous one had, right?
39:32 Speaker 02 So, but I think you end up with a contact binary scenario. Yes, you could, because we do have contact binaries where two stars end up sharing the same amount of material that's orbiting between them. They're very dangerous and ultimately, when you have two stars that are coalescing, they do go through a period where they're kind of evolving as two separate cores into a solid core. So I'm just thinking how you reverse that process. You'd have to pull those two stars. So yeah, the answer to that one is yes, there is a distance which if you could rapidly separate them and pull them apart where you're good and you will have two smaller objects that is, that is possible.
40:13 Neil deGrasse Tyson? So if we were infinitely powerful or we were the programmers of this simulation in which we all live, and there's one star that has just way too much mass and there's some needy planets out there, you could have the power to just pluck off, uh, material and just put it where you want it and scatter the stars so, so one star can become 10.
40:32 Speaker 02 Well, there is, there's definitely enough mass in some stars to pluck out hundreds of stars where there's still stars, there's still stable objects.
40:44 Neil deGrasse Tyson? Right, okay.
40:45 Speaker 02 And so that is possible, but you'd have to redistribute the material. Uh, I'm thinking of it like as a Play-Doh, like you'd have to make sure that the outer core and the inner core, because there's the.
40:54 Neil deGrasse Tyson? Plus it's very socialist and we can't have that, not at a mer- murder. You have too much mass.
41:00 Negin Farsad? But I love the idea that Jared sees the stars kind of like our senate, uh, just split in half down the middle.
41:07 Speaker 02 Right.
41:08 Negin Farsad? But I just want to say Jared, the stars are not that partisan. And if they are, Kamala Harris will come in and, and be the tie-breaking star.
41:15 Neil deGrasse Tyson? She'll tie-break that out. That's right.
41:17 Negin Farsad? Another question?
41:18 Neil deGrasse Tyson? All right. Yeah, let's do it.
41:20 Negin Farsad? Robert Weaver, another dark one. Okay, Robert Weaver, Weaver asks, what would happen if the nearest star to us blew up?
41:28 Speaker 02 Oh, I like this question. Um, so I'm not sure which star they mean because sometimes they might mean our sun. Do they mean our sun? This is, that's, that, that would be an, a, a end game scenario for us here on Earth, clearly, uh, because that's our, that's our life force. So if the closest star to us, which is the sun, blows up, um, blows up, we're, we're goners.
41:54 Neil deGrasse Tyson? Ball game over, okay.
41:55 Speaker 02 Ball game over, 100%.
41:57 Negin Farsad? It's been nice.
41:57 Speaker 02 Yeah. Uh, the next closest one to us, this is always a fun pop quiz, um, is a triple system, actually. There's three stars in that system. None of them are actually gonna go supernova. If any of them did, we'd still be in severe danger because it's actually not that far away from us. The closest star to us is our fort cloud, the like surrounding area of our solar system, stretches a third of the way out to that system. So we're already pretty close to it when it comes to like our extended family of the solar system. So uh, the nearby vicinity, what I call the spitting distance area around our solar neighborhood.
42:42 Negin Farsad? Like the suburbs of our solar neighborhood.
42:45 Speaker 02 Suburbs. Well, we're in the suburbs of the galaxy. That's true.
42:50 Negin Farsad? I got you. Okay.
42:51 Speaker 02 Yeah, we're definitely in the suburbs of the galaxy. But if any of the like 100, 100 parse, 300 light years, stars, go supernova, it's, it's gonna be a, and, once they get far enough away, it's not that bad. I don't know the exact distance where we start to say like, we've got a severe problem here. Uh, but it'd certainly be something that we could observe in a major way.
43:15 Neil deGrasse Tyson? And it would, and I, I guess if it's, if it's the Alpha Centauri system, it, it would be visible in broad daylight, right?
43:22 Speaker 02 Oh, yeah.
43:23 Neil deGrasse Tyson? Yeah, yeah, it would be like, and, and fortunately, we know what that would be if it happened, uh, and we don't have to worry about whether the, the kings will die or whether there'd be a change.
43:36 Speaker 02 The kings? Who are the kings?
43:39 Neil deGrasse Tyson? That's what I'm saying. They're not anymore, you know, but in the day, the change of emperors, you know, a new star in the sky, that something different is gonna happen.
43:47 Speaker 02 Yeah, no, none of that is an issue. I think.
43:49 Negin Farsad? Well, like, is, is something pelting us in the face? Like if one of those stars, like it, or it's just, it's dark or what?
43:57 Speaker 02 Well, when when the supernova, when a supernova occurs, it blows off highly energetic particles in in multiple directions. And if we, so a supernova that went off nearby have, one that I can use as a great example is one that happened in the year 1987. I think we were all alive, yes?
44:21 Neil deGrasse Tyson? It's the one that we saw happen in 1987.
44:25 Speaker 02 Right, we saw it happen.
44:26 Neil deGrasse Tyson? It actually happened half a million years ago. Something like that, yeah.
44:30 Speaker 02 Right, exactly. It's it's a faraway object. And in 1987, I think it, there was an operator at Los Companes Observatory, which was one of the first to see it, I believe. But it was a noticed thing. It was like, oh, this thing got bright. And then the they detected, they actually detected the earth got hit by a couple of highly energetic particles called, these neutrinos hit the earth and were detected. And we collected like, I don't know, it was like 15 of them. But we did get hit with them. But that thing is.
45:07 Negin Farsad? So far.
45:08 Speaker 02 Yes, and you do not want to get slammed by the radiation that comes from a supernova. So as much distance as you can put between yourself and that, if you're a habitable world, then keep that distance. If you're something else, though, there are things that probably want the supernova to go off. Because a supernova, when it goes off, it's actually enriching the area around it. It's dumping all this material, right? That comes from that massive star that was churning away at all this nice, higher mass elements, and it dumps them out into the area, enriching, giving feedback to the galaxy. And so next generations of stars really benefit from supernovas going off. But.
45:49 Neil deGrasse Tyson? So they're our frenemy. They can kill us, but really, we like them at some, at some point, I think.
45:56 Speaker 02 We don't know if a supernova went off that triggered our own solar system being formed. Well, our sun being formed led to our solar system being formed. But, you know, supernovas going off will trigger star formation in the galaxy. So it is a good thing. But once you're alive, you want to stay away from them.
46:15 Neil deGrasse Tyson? You sound like we have the option to run away. Keep your distance.
46:21 Speaker 02 Right. Well, I think if you're gonna find a new star to live around, you know, look around, make sure you don't have any supergiants around that look like they're going to be going supernova anytime soon. So that should go into your like, you know, when you go on Zillow.
46:38 Neil deGrasse Tyson? It's the real estate map. Yeah. Very cool.
46:41 Speaker 02 Like, don't pick an area with a super, like a giant. If you see a star that's got a really low real estate and you're like, but that's an amazing star, like, look a little closer. I bet it's got a supergiant around it. Bet there's a beetle just like right next to it.
46:56 Negin Farsad? Buying a house next to a frat, like buying a house next to a frat house or something. You don't want to do that.
47:01 Speaker 02 Yes, right.
47:03 Neil deGrasse Tyson? So Negin, we have time for like, if Jackie is good at this, we're gonna send three lightning round questions to her. Let's try it. Okay, go.
47:11 Negin Farsad? Okay, here we go. John David Newman asks, "On average, are the stars we observe furthest away from us older, bigger, and shorter-lived than the stars that we see closer to us? And what's the shortest and longest living star we've found?"
47:24 Neil deGrasse Tyson? Go.
47:24 Speaker 02 Gosh, that's so much. So the closest stars to us should not be a unique sampling in the galaxy because they, we should not be in a unique place in the galaxy. We have both young stars that are nearby and old stars that are nearby. So we do get both. The youngest stars that are near us are on the order of,
47:46 Speaker 02 depends on what you mean by near, but like, let's go to 300 light years away. Then you start getting things that are like 2 million years old or 3 million years old. But we've also got stars sweeping in that are like 10 billion years old that are near us. And so that's all what I would call spitting distance away at like, let's just say 100 light years or so away from the sun.
48:05 Neil deGrasse Tyson? Go, next one, Negin.
48:07 Negin Farsad? James Senior asks, "What starts the gravitational pull that brings the elements together to form a star? I'm guessing that in a nebula, there is an abundance of the correct ingredients to form a star, but how did stars form before there were any nebulas?"
48:21 Speaker 02 Yeah, first stars are the best stars in some ways. And that was a bunch of hydrogen coming together. Pull the hydrogen together because gravity is your friend. And gravity pulled the hydrogen together. And the first stars were mostly hydrogen. They were unstable and they blew up big time.
48:39 Neil deGrasse Tyson? Wait, but you're speaking like gravity is something separate from the hydrogen. The hydrogen atoms have gravity.
48:44 Speaker 02 Yes, right, and you get enough of them, pulls them together.
48:47 Neil deGrasse Tyson? They'll have a collective gravity, so it's the mutual gravitational attraction, not like gravity is just some thing hanging around. Well, it might be, how about dark matter? Isn't dark matter gravity?
48:56 Speaker 02 Yes.
48:56 Neil deGrasse Tyson? Sitting there minding its own business?
48:57 Speaker 02 I think we should be honest too, Neil. We're, gravity is very confusing. Gravity is not exactly the easiest thing for us as scientists to understand.
49:07 Negin Farsad? Sends so many mixed signals.
49:09 Speaker 02 I know, it does.
49:12 Speaker 02 Well, what transports it? What's its, what's its particle? Like, how does gravity work? This is...
49:17 Neil deGrasse Tyson? That's why, again, that's why we go to the bar. It's to cry over our drinks.
49:22 Speaker 02 Yeah, you get some good conversations about gravity going on.
49:24 Negin Farsad? It bought me a drink, but then it didn't really want to talk to me. What?
49:31 Neil deGrasse Tyson? So we've got to end it there. Uh, but, Jackie, thanks for coming back on StarTalk. Uh, it's always good to see you. I mean, I see you in the offices and during a science coffee, and it's great to have you part of this StarTalk enterprise. And, and again, always good to have you.
49:48 Negin Farsad? Learned so much, thank you.
49:49 Neil deGrasse Tyson? All right, so this has been StarTalk Cosmic Queries. I'm Neil deGrasse Tyson, your personal astrophysicist. As always, bidding you to keep looking up.
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