StarTalk Podcast_ The Life and Death of Stars with Jackie Faherty

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. Didn't know we know all about them, did you? And who do I have as my co-host today? Nagin Farsad. Nagin, welcome back to StarTalk.

Oh my gosh, I'm so excited about today's topic. I don't understand any of it.

Well, you're in the right place at the right time. And you're a comedian and you're a host of Fake the Nation, which I was recently a guest on. I was delighted.

Neil, you were so great. People should listen to that episode.

And you're also author of the book, How to Make White People Laugh. Now, I'd laugh just reading that title. Is that allowed?

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.

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 a thing. So 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 Faraday. Jackie, welcome.

Hi.

Hi, everybody.

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. Yes. 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?

Yeah, outlier.org is this company that was started by the co-founders of Masterclass.

Oh, okay.

Yeah, which you did a Masterclass, right?

I did a Masterclass, yeah. They're good people, all good people.

So you know that they put production value as very important in the course creation, but they also 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?

Yeah, Astro 101. Excellent, excellent.

But 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 experience. space there. And so that is.

And you have access to data that helps inform so many of our visualizations in the shows that we produce. So you're, you're like a key cog in that turning wheel of bringing the universe down to earth.

That's a nice way of saying it.

So Jackie, let me just lead off with a question for you just to get, so we're all on the same page and Nagin, 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?

Yeah, it's pretty offensive that we decide we know how they're born, right?

That's just audacious. That's like taking a snapshot of Nagin and saying, Nagin, we know when and where you were born and when you're gonna die and where you're gonna die, but you just have a snapshot of her in this one moment.

It's like the worst retroactive gender reveal party. 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, or this one's heading out of looking like the stars as we know and love them. And it's going to 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.

That's a disclaimer. We know so much, but really we don't know much at all. But we know so much.

This makes you sound a little bit like a lawyer and not a scientist when you say stuff like that.

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 like 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 like 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.

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?

That's right.

Yep.

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. Yeah. 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 like 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.

By the way, Jackie, who among us hasn't been at the Carnegie Institute for Science as a post-doctorate fellow? I'm just, you know, talk to the choir here. I mean, we've all been.

It's just a thing. Although, Nagin, did I hear Jackie say that Being a postdoc is what you are before you have your faculties. Is that what you said? Did I say that? I thought you said that.

Before you have your touch and feel, you get your postdoc.

Before you have your faculties. Your faculties are still being honed. So that's great. So we solicited questions from our Patreon members. So apparently we're playing hardball now. Do you want to get a question done? in on this, you gotta sorta get in the Patreon circle. So, Nagin, 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 hittin' at this cold, so let's do it.

Okay, you guys are up for some treats here. From Cameron Bishop, we have this question. My cosmic query is about life and death after the... Sorry. 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 prepare in advance for warning signs? Yeah.

He's worried about the family.

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 counterparts, 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 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 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.

You know, I'm biting my tongue.

I know, I see you are. I can see you biting your tongue.

A lot of restraint.

A lot of restraint. Thank you for noticing, Nagin.

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.

This sounds like a spin-off series to The Biggest Loser, like a really galaxy-wide spin-off series.

Yeah, yeah, yeah.

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.

You could say it like that. I think that.

that, you know. As long as we're going to anthropomorphize, it dies, and right while it's dying, it eats and vaporizes its children.

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. We found they've got signatures of basically pulling in the last of this material that might've 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 in science.

What?

You're saying it's like it's got food on its lips that it didn't wipe away.

Nice.

It still has evidence of eating the planet still in its mouth.

Nice, yes.

It's a lot like my toddler.

All day long. You know exactly what they've been eating all day. The ice cream drip, the candy cane.

By the way, I just want to point out, are we allowed to say white dwarfs? I just want to make sure we don't get canceled here. Yeah, we're the black dwarf.

I think we can say that.

You think we can say that. All right.

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. Najeen, what did you call it? The biggest loser aspect?

Yeah, a spinoff series of the biggest loser.

So when that happens, it's going to get hotter and Farther away from Earth. So Pluto might thaw down and be an interesting world to look at at that stage.

I ain't moving to Pluto. Don't try to get me there. That ain't happening. I'm just saying.

It's been discussed.

I'm just saying, too. It's been discussed. 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 5 billion years we have enough space travel to enable that.

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.

So we'd planet hop our way away from the sun as the sun is dying.

We keep thinking about our own solar system before we decide, like, let's kick it from this side of the planet. you know, Orion armed galaxy and head out.

Okay. All right. Just a suggestion.

Got it.

All right, keep it coming.

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 solar barcode on my nitrogen atoms? A stellar zip code for my oxygen.

Couldn't these elements have been generated in the Big Bang or during other processes?

Yeah. Jackie, what's up?

Yeah, I love this question. There is something that is kind of new into pop culture, even pop science culture, I would say. It's called the astronomer's periodic table. Have you seen this, Neil?

No, I haven't. I haven't.

It's really cool. So an 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 to form anything that's heavier than hydrogen, I can say. So hydrogen and helium, we think, come from the Big Bang. 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 was getting frustrated with it. So she created on a bar napkin one day, 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 now. 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 what we think the physical process was that led to that element emerging onto your periodic table.

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 learn 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.

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.

Uh-oh. Uh-oh, here it comes.

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, 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.

By the way, I love it.

We're all connected is what you're saying in more ways than previously known. I like that.

I love, by the way, I was going to say that I love that this scientist 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. Yeah.

Or some people drunk text people. But if you're a quality scientist, you drunk and invent new ways of understanding.

She probably drunk, yeah. She drunk texts new elements is what she's doing.

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. No, no, no. It was a bar napkin. It was a bar napkin. It's settled.

Let that one stick. We got to take a quick break. When we come back, more Cosmic Queries with Jackie Faraday. We're talking about the birth, life, and death of stars. We're back, Cosmic Queries. I'm with my co-host, Nagin Farsad. Nagin, always good to have you on Star Talk.

Oh, I love being on.

Thanks for having me. I want more of you on Star Talk, so we've got to work that out.

Totally.

And this is Cosmic Queries, always a popular variant on the Star Talk model. And today the topic is the birth, life, and death of stars. And we've got My friend and colleague, Jackie Faraday, 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.

Yeah.

All right. All right, let's do this. So, Nagim, give me some more questions.

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?

Oh, snap.

He got real hot there.

He got all philosophical on you, Jackie. Dig out of that one, Jackie.

There's a couple of triggers in there for me when it comes to words. I'll start with the biggest one, which Neil knows that 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 our sun's mass. Brown dwarfs are objects that exist in between stars and planets. Now, what people like to call them, because of 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, 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?

We don't. We don't. Advocate for them. Thank you, Jackie.

You're welcome.

Yes, I know.

They have feelings too. Right. Okay.

Yeah. There's more on this feeling thing, but 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 failure. it's a brown dwarf from some rules that people are putting in.

And Jupiter is 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 is totally good with where it is. And I'm sorry to pick on Ben, was it? I feel like I'm picking on Ben.

Woody, Woody.

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 and 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 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.

We could also, by that token, Jackie, we could say that the sun is a failed Jupiter.

Yeah, if you wanted to reverse the negativity, we could.

Yeah, let's do that. Just to balance it out over time. And then we can neutralize it in 10 years.

How about that? Yeah.

If Jupiter wanted to throw shade on the sun, it would call the sun a failed Jupiter.

Folks, Jackie is handing out participation trophies, basically, to all of the stars and planets. I think that's what's happening here.

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.

That's good.

That's pretty good, Neil. I like it.

Well done. Well done. Yeah.

All right. So, Beguine, keep going.

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? Ooh.

I like that.

Zombies.

Yeah.

Zombie stars.

Yeah.

That's the thing. Neil, you might remember we were at a science coffee recently and we were talking about zombie.

But tell people what science coffee is just so it's not like we're studying coffee.

Right. So once a week in our department of astrophysics at At AMNH, 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 check mark 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 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 Saturdays. 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 science zoom.

BC before COVID.

Before COVID times.

Yeah. But right. So the, the question is about, I've already, I've already forgotten what it was. It was on. Sorry.

I distracted you. Sorry.

How long does the death sequence take and do they ever come back to life? Right.

Okay. So the death sequence, and 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 going to 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 want to 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 universe right now. They can live for 100 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. High mass stars on the other end of it, 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 versus high mass stars. But I don't have it. The highest mass stars are, they only live for 100 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. 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 chaos ensues in the solar system. But there'll be a lot happening in, say, a billion years. It's going to 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 is 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.

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?

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 sequence.

So you're referring to astrophysically stable as distinct from emotionally stable. That would be.

A different issue.

The emotionally stable star. You could probably make a really good comic out of the stability strip for stars. There is an instability strip. 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.

And because they need more sleep, you know, and they need to be hydrated. It's like they need to meet some of their basic self-care needs.

There it is.

All of that. And so I would agree. I'm in complete agreement with this. Even though I said I don't think we should have more give emotions to these, but sometimes it helps. 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.

Or in a place where there are too many other objects that could do a gravitational slingshot around you and mess with your orbital stability. That's bad too.

Exactly. Do you want to live... So some of this could be... Like urban life, if you want to live at the center of the galaxy, that is not a solid, healthy place for most of us. Let's just all be honest. There's too much radiation.

As someone who lives in Manhattan, I take issue with that characterization.

I hear you.

It just means you're irradiated.

Irradiated in the most fun way.

So tell me about zombies now. Tell me about zombies. That was the other half of the question.

Yeah, so can a star come back to life after it's already passed through 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, right? 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 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 is getting skinnier. And so the bigger star, 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.

So you shut it off.

Yeah.

You just shut off its process.

And then you can keep going and strip it down to it's basically a planet. It's like Jupiter. And 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. It needs to have some sort of outside material or outside mechanism that ends up contributing.

So to be a zombie, you need to have a friend.

Yeah, that's a good way of putting it, Neal.

Just to help you out of the grave.

This does not track with the way The Walking Dead works, by the way.

I think it's an unwritten episode of The Walking Dead.

Yeah, it's like a nice capsule episode. I like that. Let's send that idea to them, Neil. All right.

We've got to take another break. When we come back, the third and final segment of Cosmic Queries, The Birth, Life, and Death of Stars. We're back. StarTalk Cosmic Queries Edition, The Birth, Life, and Death of Stars. Nagin Farsad, my co-host. Nagin, you're on social media, right?

I am.

You got a Twitter handle? What do you got?

I'm at Nagin Farsad on all of the things. All of the things? Yes, all of the social. Any social media you can think of, that's what it is. And it's N-E-G-I-N-F-A-R-S-A-D.

No one was vying for that name.

No, I know. Wouldn't it be funny if I was like Nagin Farsad 343 on Twitter? It's like, dang. There's a lot of us, Neil. There's a lot of us.

No, there's only one you, I'm certain of it. And Jackie, what's your social media presence?

I'm on Twitter, Twitter and Instagram. And my Twitter is at Jay Faraday. That one's easy. I feel like that's my name.

You know, F-A-H-E-R-T-Y. Yeah.

Yeah.

Thanks, Neil. And then at Instagram, it's at Jay Faraday 17.

So there were 16 other Jay Faraday.

I don't know if there was. I just like the number 17. So as soon as one is taken, I'm like, damn it. And then I automatically just jumped to 17.

I got you. Very cool.

That's a little quirk.

And on Instagram?

Instagram is Jay Faraday 17. Twitter is just Jay Faraday.

And anybody on TikTok yet? No, it's just for the youngins. That's just for the youngins.

I don't like admitting that, so.

I'm going to make an account.

Today, and it's going to be called, let's redo this, at jfairity17 at TikTok, okay? Because I'm young.

There you go. There you go. All right, so we have questions. This is our third and final segment, and Nagin, let's see how many we can squeeze in. Go for it.

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?

Yeah.

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.

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 going to 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 is going to be an issue. So for these giants, liquid water, liquid water is going to be liquid water is going to be an issue on the surface. I should say too. That's very important because you can have water deep down under a crust device 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 is, that area moves around a lot as that star is moving through the phase. And so how long you need for biological life to show up, 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 and some of the outer objects in our solar system, there's awesome moons like Enceladus and Europa, 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. The habitable zone will start stretching away from our sun and they're already created objects, which may already have a lot of the ingredients that you need for organic life. And so I would not count it out as impossible to But you do need some of the ingredients there already. So the prescription is have something there,

be ready, and maybe the habitable zone will show up at your door and you'll melt down and life could emerge. Fluently.

All right. Yeah.

I like it. All right, keep it coming, Nagin.

Okay, Jared Sims says, hello, Dr. Tyson, Dr. Faraday, and of course the hilarious Nagin. I included that part because there's a compliment to me in there. Jared asks, what would happen?

Jared's favorite comedian ever in the whole universe.

That was in parentheses. 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?

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.

Yeah.

Yeah. I will say a lot of these questions are a little dark and a little dangerous. Like I don't know 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?

Just a laser. Just laser. Cut the thing in half. And then what happens next?

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 that stars don't collide very often, but it can happen. 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 very science fiction in my quick reaction to this.

But I'm imagining, but if it is science fiction and you have these big old hands, let's say 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?

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 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 possible.

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 material and just put it where you want it and scatter the the stars so one star can become 10.

Well, there's definitely enough mass in some stars to pluck out hundreds of stars where there's still stars. There's still stable objects. So that is possible, but you'd have to redistribute the material and 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... Plus it's very socialist, and we can't have that.

No.

You have too much mass.

But I love the idea that Jared sees the stars kind of like our Senate, just split in half down the middle. Right. But I just want to say, Jared, the stars are not that partisan. And if they are, Kamala Harris will come in and be the tie-breaking star.

She'll tie-break that out.

Yeah. That's right. Another question? All right.

Yeah, let's do it.

Robert Weaver, another dark one. Okay, Robert Weaver asks, what would happen if the nearest star to us blew up?

Oh, I like this question. So I'm not sure which star they mean because sometimes they might mean our sun. Do they mean our sun? That would be an endgame scenario for us here on Earth, clearly. Because that's our life force. So if the closest star to us, which is the sun, blows up, we're goners.

Ball game over.

Ball game over, 100%. Yeah. The next closest one to us, this is always a fun pop quiz, is a triple system, actually. There's three stars in that system. None of them are actually going to 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 Oort cloud. The 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 our extended family of the solar system. So the nearby vicinity, what I call the spitting distance area around our solar neighborhood.

Like the suburbs of our solar neighborhood. Suburbs.

Well, we're in the suburbs of the galaxy. That's true.

Oh, gotcha. Okay.

Yeah, we're definitely in the suburbs of the galaxy. But if any of the like 100, 300 light years stars go supernova, it's going to be a. 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. But it'd certainly be something that we could observe in a major way.

And I guess if it's the Alpha Centauri system, it would be visible in broad daylight.

Oh, yeah.

Yeah, yeah. It would be like... And fortunately, we know what that would be if it happened. And we don't have to worry about whether the kings will die or... or whether there'd be a change. The kings?

Who are the kings, Neil?

That's what I'm saying. They're not anymore.

No.

But in the day, the change of emperors, a new star in the sky, that something different is going to happen.

Yeah, no, none of that is an issue.

But is something pelting us in the face? If one of those stars, or it's just... It's dark or what? Like, I don't know.

Well, when a supernova occurs, it blows off highly energetic particles in multiple directions. And if we, so a supernova that went off nearby, one that I could use as a great example is one that happened in the year 1987. I think we were all alive.

Yes?

It's the one that we saw happen in 1987.

Yes.

Right.

We saw it happen in 19... It actually happened half a million years ago.

Yes.

Something like that, yeah.

Right, exactly.

It's a faraway object. And in 1987, I think there was an operator at Las Campanas 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 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.

So far. 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 the 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.

So they're our frenemy. They can kill us, but really we like them at some point.

Well, 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 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.

You sound like we have the option to run away. Keep your distance.

Right.

Well, I think if you're going to find a new star to live around, you know, look around. Make sure you don't have any super giants 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 and you try.

And- It's the real estate map. Yeah, very cool.

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- Get out of there. But that's such an amazing star, like look a little closer. I bet it's got a super giant around it. I bet there's like Beetlejuice.

Like right next to it. It's like buying a house next to a frat house or something. You don't want to do that.

That's right.

Yes, right.

So Nagin, we have time for like, If Jackie is good at this, we're going to send three lightning round questions to her. Let's try it. Okay, go.

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?

Go.

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, 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. I feel like I answered that.

Okay. Yeah, but that was a little long for a sound bite. Let's see if we can make it even shorter.

Go.

Next one, Nagin.

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? Ooh.

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.

Wait, but you're speaking like gravity is something separate from the hydrogen. The hydrogen atoms have gravity.

Yes. Right.

And you get enough of them.

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? Yes.

I think we should be honest too, Neil. Gravity is very confusing. Gravity is not exactly the easiest thing for us as scientists to understand the mechanisms.

I know, it does.

Well, what transports it? What's its particle? How does gravity work?

Nagin, that's why we go to the bar.

It's to cry over our drinks.

Yeah, you get some good conversations about gravity.

It bought me a drink, but then it didn't really want to talk to me.

What? So we've got to end it there. Jackie, thanks for coming back on StarTalk.

Yeah.

It's always good to see you. I mean, I see you in the offices and during Science Coffee, and it's great to have you part of the StarTalk enterprise. And Nagin, always good to have you. I've learned so much. Thank you. And your kid's doing well? Grandma taking care of him now?

Oh, yeah. You said earlier? They're doing their back-breaking work of running after a toddler.

Okay, so that means it's not as fun with them running into your Zoom screen.

See, that's part of it. They've managed to keep her at bay. 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.

StarTalk Podcast_ The Life and Death of Stars with Jackie Faherty

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