Cosmic Queries – Between Planets and Stars, with Jackie Faherty

What lies hidden in the murky hallways of the cosmos? Neil deGrasse Tyson, astrophysicist Jackie Faherty, PhD, and co-host Chuck Nice answer your fan-submitted questions on brown dwarfs, interstellar objects, Planet 9, and more! NOTE: StarTalk+ Patrons and All-Access subscribers can watch or listen to this entire episode commercial-free here: https://www.startalkradio.net/show/cosmic-queries-between-planets-and-stars-with-jackie-faherty/ Thanks to this week’s Patrons for supporting us: Scott Peterson, Kody Krier, Anette Woolsey, Joe Aguirre, Daniel Hargrove, Jill Burkey Image Credit: NASA, ESA, Hubble; Processing & License: Judy Schmidt.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  From the American Museum of Natural History in New York City, and beaming out across all of space and time, this is StarTalk, where science and pop culture collide. This is StarTalk. I'm your host, Neil deGrasse Tyson, your personal astrophysicist. And today, we're gonna have a cosmic queries edition of StarTalk, with my co-host Chuck Nice.

• 0:27Chuck Nice?

  Yes.

• 0:28Neil deGrasse Tyson?

  Chuck, you baby.

• 0:28Chuck Nice?

  Hey Neil.

• 0:29Neil deGrasse Tyson?

  All right.

• 0:29Chuck Nice?

  What's happening?

• 0:30Neil deGrasse Tyson?

  Someone slipped in between us here.

• 0:31Chuck Nice?

  That's right.

• 0:31Neil deGrasse Tyson?

  I've got my friend and colleague.

• 0:33Chuck Nice?

  Yes.

• 0:33Neil deGrasse Tyson?

  Not only professional colleague, but museum colleague Jackie Farady.

• 0:36Chuck Nice?

  That's right.

• 0:37Speaker 02

  Hi.

• 0:37Neil deGrasse Tyson?

  Jackie in the house.

• 0:38Speaker 02

  Hi, in the, in the, in two houses. Double house here.

• 0:42Chuck Nice?

  Double house.

• 0:42Neil deGrasse Tyson?

  Double house. Jackie is one of the world's experts on the, the worlds that exist between planets and stars.

• 0:52Chuck Nice?

  Wow.

• 0:53Neil deGrasse Tyson?

  There's not a sharp boundary there. You might have thought so, or maybe you never thought about it. She's thought about it.

• 0:57Chuck Nice?

  Yes.

• 0:58Neil deGrasse Tyson?

  And she and her peep, her peeps. She's got a whole community of people. In fact, after we hired her, she brought other people after she came. So, this place, the American Museum of Natural History.

• 1:10Chuck Nice?

  Right.

• 1:10Neil deGrasse Tyson?

  Is one of the intellectual centers of this subject. Because of this woman right here.

• 1:15Speaker 02

  That's correct.

• 1:15Chuck Nice?

  That's really cool.

• 1:18Speaker 02

  I'm gonna take ownership of that.

• 1:19Chuck Nice?

  You sure?

• 1:19Speaker 02

  Yeah. We actually have a, our research group has stickers and t-shirts and logo, we have a logo. And we made it out of-

• 1:28Neil deGrasse Tyson?

  Is that the logo with the, with the, with the-

• 1:30Speaker 02

  Subway letters.

• 1:30Neil deGrasse Tyson?

  Subway symbols.

• 1:31Speaker 02

  Yeah.

• 1:32Chuck Nice?

  Oh. Because our subway symbols in New York City are circles.

• 1:36Neil deGrasse Tyson?

  Yes.

• 1:37Chuck Nice?

  With letters inside of them.

• 1:38Neil deGrasse Tyson?

  Yes, they are.

• 1:38Chuck Nice?

  So what are, what is, what's your design there?

• 1:40Speaker 02

  So we are BD NYC.

• 1:43Chuck Nice?

  Oh.

• 1:43Speaker 02

  Which stands for Brown dwarfs.

• 1:45Chuck Nice?

  Right.

• 1:45Speaker 02

  In New York City, research group.

• 1:46Neil deGrasse Tyson?

  Plus, a B train stops at this institution.

• 1:48Chuck Nice?

  It certainly does.

• 1:49Speaker 02

  So does the C.

• 1:50Chuck Nice?

  That's correct.

• 1:50Speaker 02

  B and C, there you go.

• 1:52Neil deGrasse Tyson?

  So, we solicited questions on, from, from our fanbase, telling them, we're gonna have the world's expert on this sort of netherworld between planets and stars.

• 2:03Chuck Nice?

  Yes.

• 2:03Neil deGrasse Tyson?

  And in came hundreds of questions.

• 2:05Speaker 02

  Hundreds.

• 2:06Neil deGrasse Tyson?

  Yes.

• 2:07Speaker 02

  Hundreds.

• 2:07Neil deGrasse Tyson?

  Hundreds of questions.

• 2:09Chuck Nice?

  Yes.

• 2:09Neil deGrasse Tyson?

  You've got them.

• 2:10Chuck Nice?

  And I've got them.

• 2:10Neil deGrasse Tyson?

  Neither of us have seen it.

• 2:11Chuck Nice?

  No, you haven't.

• 2:12Neil deGrasse Tyson?

  And.

• 2:12Chuck Nice?

  Not that it's a test.

• 2:13Neil deGrasse Tyson?

  No, no, I love shows like this when I have one of my, my astrophysics colleagues.

• 2:17Chuck Nice?

  Mm-hmm.

• 2:17Neil deGrasse Tyson?

  Cause then I'll have to say a thing.

• 2:18Chuck Nice?

  Right.

• 2:19Neil deGrasse Tyson?

  She knows everything. I'll just, I will go get lunch and then you, you tell me when you're done.

• 2:22Chuck Nice?

  Right, so.

• 2:23Speaker 02

  I like that Neil saying, "I know everything." That's a nice, that's a nice compliment. Thank you, Neil.

• 2:28Chuck Nice?

  Yeah. Alright, well, listen, why don't we jump into it with our first question, which is always from a Patreon patron?

• 2:34Neil deGrasse Tyson?

  Alright.

• 2:34Chuck Nice?

  Uh, okay, here we go. This is AMZ Industries. Wow, we've gone corporate with Patreon patrons.

• 2:40Speaker 02

  AMZ.

• 2:41Chuck Nice?

  AMZ Industries.

• 2:42Neil deGrasse Tyson?

  New York Stock Exchange listing.

• 2:44Chuck Nice?

  Tell me about it.

• 2:45Neil deGrasse Tyson?

  AMZ Industries.

• 2:46Chuck Nice?

  Right. Um, AMZ says, um, the sun is the biggest star in our solar system. I believe it's also the only star in our solar system.

• 2:56Neil deGrasse Tyson?

  Keep going.

• 2:56Chuck Nice?

  Okay.

• 2:57Speaker 02

  Yeah.

• 2:58Chuck Nice?

  Maybe I'm wrong. I'm just saying.

• 2:59Speaker 02

  You're gonna hold that one, yeah.

• 3:00Chuck Nice?

  Okay. Uh, do we know a star or any other object in space or interstellar space that is bigger than our sun? Okay.

• 3:09Speaker 02

  Hmm.

• 3:10Chuck Nice?

  Uh.

• 3:10Neil deGrasse Tyson?

  Okay, so just see, it's, they just mixed galaxy with solar system.

• 3:13Chuck Nice?

  That's what they did.

• 3:14Neil deGrasse Tyson?

  That's all.

• 3:14Chuck Nice?

  Thank you.

• 3:15Neil deGrasse Tyson?

  Yes.

• 3:15Chuck Nice?

  I'm trying to figure this out, but you got it.

• 3:17Speaker 02

  Yeah.

• 3:17Chuck Nice?

  That's what they did. So, uh, um, also to Jackie, um, do you believe in zodiac signs? Uh-huh.

• 3:27Speaker 02

  Mm-hmm.

• 3:27Chuck Nice?

  Okay. Alright.

• 3:29Speaker 02

  Uh, okay, twofold question, both of which are interesting to answer.

• 3:33Neil deGrasse Tyson?

  And they both sound completely unrelated to each other.

• 3:35Speaker 02

  They are unrelated to each other, I believe.

• 3:38Chuck Nice?

  I think one is a genuine interest in the cosmos and a, and the other is a genuine interest in you.

• 3:44Neil deGrasse Tyson?

  Oh.

• 3:45Speaker 02

  Oh, I love it. So I will go with the first one is the sun in our, okay, so yes, it's the only star that we know of in our solar system. Although we have searched for another object that might be, maybe not a star, but one of these objects I study, a brown dwarf.

• 4:02Chuck Nice?

  Brown dwarf.

• 4:02Speaker 02

  That might be a companion to our own sun, since it's alone, it's by itself, it doesn't have a partner.

• 4:07Chuck Nice?

  So.

• 4:08Neil deGrasse Tyson?

  We have to be orbiting really far away.

• 4:09Chuck Nice?

  Yeah, I was gonna say, cause you're talking, what, what, what, what I believe we're talking about, tell me if I'm wrong, is that sometimes there are anomalies in the gravitational movement of objects in our neighborhood, right?

• 4:25Speaker 02

  So I think you're going with the planet nine explanation.

• 4:27Chuck Nice?

  Okay, that's what I.

• 4:28Speaker 02

  Which is, yeah, and that's also been been pulled on and is very popular right now.

• 4:33Neil deGrasse Tyson?

  Planet nine, not Pluto, just to be clear.

• 4:36Chuck Nice?

  Right.

• 4:36Speaker 02

  Right, yes.

• 4:36Neil deGrasse Tyson?

  On this show, we gotta be clear about it.

• 4:38Speaker 02

  And also, we can discuss why that word planet's not very good in this context, anyway.

• 4:41Chuck Nice?

  Right.

• 4:42Speaker 02

  So, an object outside of what's currently Pluto's position that might be tugging on objects in the outer part of the solar system. The Kuiper Belt, which is this this this area of things that are leftover from when the solar system formed. Uh, and whether or not there's something else that's well beyond that.

• 4:59Chuck Nice?

  Right.

• 4:59Speaker 02

  Possibly there's indications, theorists certainly think that. Um, but um, but there was this nemesis hypothesis that existed several several years ago.

• 5:09Chuck Nice?

  Okay.

• 5:09Speaker 02

  For which that possibly you could link up mass extinctions that happened on this planet with a highly eccentric other object that might have been.

• 5:19Neil deGrasse Tyson?

  Orbit is eccentric, right.

• 5:21Speaker 02

  Yes, orbit is eccentric.

• 5:22Neil deGrasse Tyson?

  It's not emotionally eccentric.

• 5:24Speaker 02

  It could have been emotionally eccentric.

• 5:26Chuck Nice?

  Although it does spend a lot of time alone, so maybe, you never know.

• 5:29Speaker 02

  Why are we giving emotions to the object? Like, this is part of the problem. People put so much emotion on these objects, they wanna feel them.

• 5:37Chuck Nice?

  Yeah.

• 5:38Speaker 02

  Yeah.

• 5:39Neil deGrasse Tyson?

  You just called the thing eccentric, that's all.

• 5:40Speaker 02

  Yes, eccentric, right, so, uh, so that it would have an eccentric orbit. Uh, and that possibly was every time it got into some area of the outer solar system, it would kick a bunch of stuff in uh, towards the, uh, towards our area and cause possibly mass extinctions.

• 5:55Neil deGrasse Tyson?

  Comets that would then hit us, yeah, yeah.

• 5:57Speaker 02

  Comets, asteroids, um, and so that's, that's basically, we've looked far and near and we haven't found anything.

• 6:04Chuck Nice?

  Got you.

• 6:04Speaker 02

  So possibly that's out, um.

• 6:06Neil deGrasse Tyson?

  So nemesis was the proposed name if such an object existed and that would have been its name had we found it.

• 6:12Speaker 02

  Yeah, and nemesis is the idea that it's our nemesis.

• 6:16Chuck Nice?

  Right.

• 6:16Speaker 02

  The Earth's nemesis, not necessarily the Sun's.

• 6:18Chuck Nice?

  Right.

• 6:18Speaker 02

  The Earth's, because if it's gonna, uh, basically go far.

• 6:22Chuck Nice?

  If it's launching crap at us.

• 6:23Neil deGrasse Tyson?

  Salvo.

• 6:25Speaker 02

  Why would you want that?

• 6:26Chuck Nice?

  Right.

• 6:27Speaker 02

  That would feel like your nemesis, right?

• 6:29Neil deGrasse Tyson?

  Sure, sure.

• 6:30Speaker 02

  So that, okay, so beyond that, the question's asking if there's a, um, a star that's bigger than our our own Sun. And that's like, yeah, definitely, there's so many. My favorite star in the the nighttime sky is called Eta Carina.

• 6:45Chuck Nice?

  Eta Carina.

• 6:46Speaker 02

  You know Eta Carina. Eta Carina's a deity.

• 6:49Chuck Nice?

  And I love the fact that it actually sounds like a pop star. You know what I mean?

• 6:52Neil deGrasse Tyson?

  Eta?

• 6:53Speaker 02

  Yeah.

• 6:53Chuck Nice?

  Eta Carina.

• 6:54Speaker 02

  Yeah. It's in the constellation Carina.

• 6:57Neil deGrasse Tyson?

  That'd make a good ice cream flavor.

• 6:59Chuck Nice?

  That, Eta Carina. I ate a Carina?

• 7:02Neil deGrasse Tyson?

  Carina is the name of the flavor.

• 7:03Chuck Nice?

  And I ate a Carina.

• 7:04Neil deGrasse Tyson?

  Yeah.

• 7:05Speaker 02

  Wow, I wouldn't have put that in there, but okay. All right.

• 7:08Neil deGrasse Tyson?

  I like ice cream.

• 7:09Speaker 02

  It's in the homunculus nebula. Can you make that work? As like the homunculus nuts that somehow somebody could make that you'd put on the ice cream? Well, so Eta Carina is a very large star. And we now think that it's actually two stars, a binary star system.

• 7:23Chuck Nice?

  Oh.

• 7:23Speaker 02

  Uh, we call it a luminous blue variable. It's this object that's very, very massive. And so we think it's two and so forty to fifty times the mass of our, our own sun, but probably two of them. They go around each other eclipsing each other so that you can actually see the light of one dip very, very periodically.

• 7:40Neil deGrasse Tyson?

  Such a variability you're talking about.

• 7:41Speaker 02

  Yeah.

• 7:42Chuck Nice?

  Yeah. So let me just ask you this. Uh, even though it's a body moving in front or transiting another body, how, is one slightly larger than the other? Because where, they're both luminous.

• 7:56Speaker 02

  Yeah.

• 7:57Chuck Nice?

  So the idea of a transit is one blocks light from the other, but if they're both glowing, wh- wh- what are you measuring?

• 8:03Speaker 02

  So they're not the exact same mass.

• 8:05Chuck Nice?

  Okay.

• 8:06Speaker 02

  So you'd have one that's say sixty times the mass of a sun and the other's thirty times the mass of the sun.

• 8:11Chuck Nice?

  All right.

• 8:11Speaker 02

  There's even some hypothesis that there's a triple system in there. There's three, not just two.

• 8:17Chuck Nice?

  Wow.

• 8:17Speaker 02

  So I'm noting Eta Carina because I think it is just an awesome star, uh, or star system. But that's not the most massive.

• 8:26Neil deGrasse Tyson?

  Photos of that, right?

• 8:26Speaker 02

  Oh, yeah.

• 8:27Neil deGrasse Tyson?

  Yeah, yeah, yeah, you check that out. Yeah, we might put one on the website here. Yeah.

• 8:30Speaker 02

  You should.

• 8:31Chuck Nice?

  That's cool.

• 8:31Speaker 02

  Cause it was part of an HST legacy project.

• 8:34Neil deGrasse Tyson?

  Hubble Space Telescope, yeah.

• 8:35Speaker 02

  Oh, sorry, Hubble Space Telescope, yes.

• 8:37Neil deGrasse Tyson?

  Don't apologize.

• 8:38Speaker 02

  Yeah, you're right.

• 8:39Chuck Nice?

  You're in the lingo, girl.

• 8:40Speaker 02

  I'm in the lingo.

• 8:41Chuck Nice?

  Do the lingo thing.

• 8:43Neil deGrasse Tyson?

  HST and elemental P. Right, okay.

• 8:46Speaker 02

  Thank you, Neil. Um, and it, it's a, uh, so there's, there's a lot of data on, and on Eta Carina. Uh, but it's not the most massive. You get even more massive. There's a hundred, two hundred times the mass of our own sun.

• 8:59Chuck Nice?

  Wow.

• 8:59Speaker 02

  And these are not stable systems. This is, these stars.

• 9:03Neil deGrasse Tyson?

  Again, we're not referring to their motions.

• 9:04Chuck Nice?

  Right. Right, exactly.

• 9:06Neil deGrasse Tyson?

  They have eccentric stars and unstable stars.

• 9:08Chuck Nice?

  I like where this is going.

• 9:11Neil deGrasse Tyson?

  We also have degenerate stars as well, that's another thing.

• 9:13Chuck Nice?

  Really?

• 9:13Neil deGrasse Tyson?

  Yes, it's an actual kind of star.

• 9:16Chuck Nice?

  Is that, okay, I can't even tell you what, forget it. I just, my mind immediately went to a star.

• 9:21Neil deGrasse Tyson?

  And just for constellation weenies out there, Carina is a constellation visible primarily in the southern hemisphere, and it's part of the constal- it's part of a much larger constellation that used to be one piece. And it's the, the ship of, uh, the Argonauts, okay, Argo Novis is the ship. And it's just, Carina's the, is the, is the keel, I think?

• 9:46Speaker 02

  The keel, yeah.

• 9:48Neil deGrasse Tyson?

  Yeah, so what they did was that constellation was way too big for its britches, so they broke it up into parts. There's a compass, there's a sail, there's the hull, there's the, there, and so this is, it is the eta if brightest

• 10:00Speaker 02

  Right.

• 10:01Neil deGrasse Tyson?

  object in the constellation Carina. So alpha, beta, gamma, delta, epsilon, zeta, eta, so it'd be the seventh brightest star.

• 10:08Speaker 02

  And that's important also because it's not always the eta, because that's what it was catalogued at, but at one time it was one of the brightest stars in the nighttime sky because the thing is going through massive and insane explosions, and it's just dumping material off, which is creating this gorgeous-

• 10:24Chuck Nice?

  That makes the beautiful photos.

• 10:26Speaker 02

  Yes, the nebula that's around it is so unbelievably attractive to look at. And that's just from just dumps of material.

• 10:34Chuck Nice?

  Like that?

• 10:35Speaker 02

  Yeah.

• 10:35Neil deGrasse Tyson?

  It's really a crime scene.

• 10:36Chuck Nice?

  Right.

• 10:37Neil deGrasse Tyson?

  You're gonna see this gas just spilling out.

• 10:39Speaker 02

  So good.

• 10:39Neil deGrasse Tyson?

  Something happened down in there.

• 10:41Speaker 02

  Something bad happened, and something is continually bad happening. I mean, I would love to fly close and have a look at that thing. And you wouldn't want to be close as a human because there's probably a lot of really bad radiation around there, but man, would it be a sight, because it is really pretty.

• 10:58Chuck Nice?

  That's very cool.

• 10:59Speaker 02

  To the human eye.

• 11:00Chuck Nice?

  So eta Carina.

• 11:01Speaker 02

  Yeah.

• 11:02Chuck Nice?

  Nice.

• 11:02Neil deGrasse Tyson?

  Also, the sun is large enough, if you hollowed it out,

• 11:04Chuck Nice?

  Right.

• 11:04Neil deGrasse Tyson?

  you could pour a million Earths into it.

• 11:07Chuck Nice?

  Our sun.

• 11:08Neil deGrasse Tyson?

  Our sun.

• 11:08Chuck Nice?

  Right.

• 11:09Neil deGrasse Tyson?

  And now we're talking about stars bigger than that.

• 11:10Chuck Nice?

  That right.

• 11:10Speaker 02

  Much bigger, much, much, much bigger, yeah.

• 11:13Chuck Nice?

  And so these, these supermassive stars, these are, these are the ones that become black holes. Like, our sun couldn't become a black hole, it couldn't.

• 11:19Speaker 02

  No.

• 11:19Chuck Nice?

  Our sun couldn't become a black hole.

• 11:20Speaker 02

  Not massive enough, but these are, these are the ones, like, you look at these stars, luminous blue variables, and then there's another kind, they're called Wolf Rayette stars. So there's actually somebody here-

• 11:29Chuck Nice?

  Wolf Rayette?

• 11:30Speaker 02

  Yes. Yes, actually debatable if it's Wolf Rayet or Wolf Rayet.

• 11:35Chuck Nice?

  Oh, is that the deal? So the people, did they discover this?

• 11:38Neil deGrasse Tyson?

  Well, they, they first studied them in an important way.

• 11:41Chuck Nice?

  Alright.

• 11:42Neil deGrasse Tyson?

  And so then realized that no other stars look like those do, so they became their own category.

• 11:46Chuck Nice?

  Nice.

• 11:46Neil deGrasse Tyson?

  Wolf Rayet. R A Y E T.

• 11:49Chuck Nice?

  Okay.

• 11:49Neil deGrasse Tyson?

  If it's French, you leave, you don't pronounce the trailing consonant.

• 11:52Chuck Nice?

  Right, so Wolf Rayet. Nice. Alright, and for the second question.

• 11:56Neil deGrasse Tyson?

  Re-read that, please.

• 11:57Chuck Nice?

  Which is, do you believe in Zodiac signs?

• 12:00Speaker 02

  Uh, so what I, I, I believe is such an interesting thing. There are constellations in the nighttime sky, which are the markers for where the ecliptic of the path that the sun takes in the sky and all the planets and the moon they take. Uh, and so those are designations in the sky and that is, it's where the, the, um, the sun and the planets and the moon all move. Yeah. I don't place any significance on, um, what people like to do in reading their astrological, uh, sign. I'm actually not even sure what my sign is.

• 12:31Chuck Nice?

  Oh, wow. Hmm. When were you born?

• 12:33Speaker 02

  Not totally true. I do know what it is, but I'm just...

• 12:35Neil deGrasse Tyson?

  But you don't think about it or care about it?

• 12:37Speaker 02

  I don't think about it too much. Right.

• 12:39Chuck Nice?

  Mine is cancer. I'm a festering malignancy. Thank you.

• 12:43Speaker 02

  Does it feel accurate?

• 12:46Speaker 02

  Oh, man.

• 12:48Chuck Nice?

  Alright.

• 12:49Neil deGrasse Tyson?

  Alright.

• 12:49Chuck Nice?

  Enough of that.

• 12:50Neil deGrasse Tyson?

  Thank you, Jackie, for that. Alright.

• 12:51Chuck Nice?

  That was great. Wow. I got so much out of that, man.

• 12:54Neil deGrasse Tyson?

  What else you got there?

• 12:55Chuck Nice?

  Alright, why don't we, um, this is, uh, Sherman from San Diego says...

• 13:00Neil deGrasse Tyson?

  Are we still on the Patreon?

• 13:02Chuck Nice?

  This is a Patreon, Patreon.

• 13:03Neil deGrasse Tyson?

  Okay.

• 13:03Chuck Nice?

  Sherman from San Diego. Sherman says, uh, "Hi, Dr. Tyson, and hi, Dr. Farady. Understanding that it's only been a few decades since the discovery of the first exoplanets, there is still a lot we don't know about even the closest ones to our solar system." What tools and or resources are needed in the works or in the works to help us better understand the nature and composition of these objects? So, that's a very good question. Is there anything new and exciting that helps us?

• 13:36Neil deGrasse Tyson?

  Can I pre-pen that question by asking you? Are your methods and tools to find the worlds between planets and stars, do you have overlap with the methods and tools of those who are finding planets?

• 13:48Speaker 02

  Yeah, and I actually think this would drive the question of what do we mean when we say the word planet in this particular instance? Because the objects that I study that are, that I get the most excited about studying are ones that we sometimes refer to as rogue worlds, as they are the same mass as the objects that others might want to call a planet. But those objects orbit a star. And the ones that I study don't orbit a star. They're in between, yeah, they just, they're off there, they're alone, they have no host star. So there's nothing.

• 14:22Neil deGrasse Tyson?

  They're homeless.

• 14:23Speaker 02

  Yeah, we call them orphan, to be nicer maybe.

• 14:25Chuck Nice?

  Wow.

• 14:26Neil deGrasse Tyson?

  Orphan, homeless, rogue.

• 14:27Chuck Nice?

  I'm an orphan world.

• 14:28Speaker 02

  The orphaned objects that are out there. So that what I do, because it's a lot easier for you to attempt to get to what's in the atmospheres of these objects, when they don't have a host star that you have to block the light of, because the contrast ratio is so large.

• 14:42Neil deGrasse Tyson?

  I have thought about that.

• 14:43Speaker 02

  It's so much easier.

• 14:44Neil deGrasse Tyson?

  Is that like, like seeing a firefly in a Hollywood searchlight? You can't, the brightness contrast is so high, you can't see the dim things. So you got objects where there's no main star, so it's just the object itself.

• 14:57Speaker 02

  Yeah, just it on its own. But this is where it gets controversial, right? Because it could be the exact same mass, temperature, gravity, the whole deal, that we would call an object around another star, but because we find it alone, we call them brown dwarfs. And when they're the lowest mass, so not getting too far down this rabbit hole, which I assume you want me to define what a brown dwarf is at some point.

• 15:22Chuck Nice?

  Yeah, I was gonna say.

• 15:23Speaker 02

  Because it's probably important for your audience to understand what I'm an expert in.

• 15:27Neil deGrasse Tyson?

  But just quickly, you're saying that location matters in how you classify such an object?

• 15:35Speaker 02

  We don't have a good running definition right now.

• 15:38Neil deGrasse Tyson?

  Yeah, it is.

• 15:39Speaker 02

  For what it is that we'll call this high mass end problem outside of our own solar system.

• 15:45Neil deGrasse Tyson?

  High mass planet.

• 15:46Speaker 02

  High mass planet. High mass, so planet or.

• 15:49Neil deGrasse Tyson?

  So what's a brown dwarf?

• 15:51Speaker 02

  So brown dwarfs are these objects that exist in mass in between stars and planets, or whatever, the gray area in between. And the idea being that when you form a star, you have a giant molecular cloud of hydrogen, and it fragments into pieces. Whatever causes the fragmentation, the compression of the gas, it breaks off into pieces, the smallest possible pieces that could fragment off.

• 16:13Neil deGrasse Tyson?

  Wait, so you have the main piece, that's the main star?

• 16:16Speaker 02

  Well, it's lots of pieces, right?

• 16:18Neil deGrasse Tyson?

  Okay, but one of them is gonna, the big one's gonna be the star.

• 16:21Speaker 02

  There could be hundreds of them that'll be stars.

• 16:23Neil deGrasse Tyson?

  Oh, of course, alright. So now you got the other bits and pieces, go on.

• 16:25Speaker 02

  Yeah, so there'll be a whole spectrum, a whole distribution of objects, that will break off out of a gigantic molecular cloud.

• 16:32Neil deGrasse Tyson?

  Mm-hmm.

• 16:32Speaker 02

  And this molecular cloud will break down into, once you compress it, so that all of the gas then gets pushed together, and then enough so that the pressure there ignites the cores of these things that break off into tiny pieces. The smallest of the pieces end up being these objects that don't even know that they don't have enough mass to get the core hot enough to get nuclear burning going.

• 16:58Chuck Nice?

  But they do it anyway?

• 17:00Speaker 02

  No!

• 17:02Speaker 02

  No, this is why-

• 17:03Neil deGrasse Tyson?

  They think they're gonna be a star, but they're not.

• 17:05Speaker 02

  So, whatever, now you guys are putting a motion on it. They don't know what they should or shouldn't be, they're just existing. And so this, this is why people called them failed stars.

• 17:15Neil deGrasse Tyson?

  Right.

• 17:15Speaker 02

  Because they're not getting enough mass. But I look at it and like, whatever dude, like, who cares? It is existing with not enough mass, that's fine. It doesn't have the mass, instead, it can't get that nuclear engine going that's at the center of our sun.

• 17:29Neil deGrasse Tyson?

  Right.

• 17:29Speaker 02

  Instead, it's like a coal plucked from a fire, it just cools through its life. And that's it, and that is in between, basically what we say is the top mass for that that it happens is seventy-five times the mass of Jupiter, seventy-five Jupiters.

• 17:42Neil deGrasse Tyson?

  That would be a star.

• 17:43Speaker 02

  That's the border, right? Exactly, and this is very metallicity dependent, like, how much, how much metallicity, how many, how much iron?

• 17:51Chuck Nice?

  What's metallicity, oh, okay, I got you. So at the core, like, okay.

• 17:55Speaker 02

  Heavy elements. Uh, so how much of that was available will change, like, how much mass you need to get the core burning. But then, uh, the lower end of it, the low end-

• 18:06Speaker 02

  I don't know. What's the lowest mass fragment that you can break off? This is a huge discussion in astronomy right now. What is the lowest mass piece that breaks off?

• 18:14Neil deGrasse Tyson?

  And still becomes a thing.

• 18:15Chuck Nice?

  And is a thing. That right.

• 18:17Neil deGrasse Tyson?

  All right.

• 18:17Chuck Nice?

  That thing that doesn't know what it is.

• 18:19Speaker 02

  But then, wait, one last thing on it. One last thing, because I know we have to stop. But the planet would be opposite end of this. Can you form an object, the planets form in a disk around a star? But how big can it get around a star? So now you've got two competing things. You've got objects that form by breaking up a cloud that then self-fragments and blah, blah, blah, blah. And then you've got a disk around a forming star. And how big can that object get?

• 18:49Chuck Nice?

  Wow.

• 18:50Neil deGrasse Tyson?

  Okay.

• 18:50Speaker 02

  Planet versus brown dwarf.

• 18:51Neil deGrasse Tyson?

  We gotta take a quick break.

• 18:52Speaker 02

  Mm-hmm.

• 18:52Neil deGrasse Tyson?

  So that's the brown dwarf establishment right there.

• 18:56Chuck Nice?

  As opposed to my brown dwarf, which was the dwarf that was never painted by Disney because he was racist.

• 19:02Speaker 02

  Wow.

• 19:03Neil deGrasse Tyson?

  The eighth dwarf, yes. Chuck has issues. We're getting him through. When we come back, more with Jackie Farady on the world between planets and stars on StarTalk.

• 19:32Speaker 03

  Bringing space and science down to earth. You're listening to StarTalk.

• 19:48Neil deGrasse Tyson?

  We're back. StarTalk, Cosmic Aquarius, the worlds between stars and planets. Where are they? What are they? We got a word for them, but do we understand them? And our best chance of understanding them is this woman right here.

• 20:03Chuck Nice?

  Yes.

• 20:04Neil deGrasse Tyson?

  Jackie Farady in the house.

• 20:06Chuck Nice?

  Yes, yes.

• 20:06Neil deGrasse Tyson?

  Friend and colleague in the Department of Astrophysics, right here at the American Museum of Natural History. And you just described something I hadn't fully appreciated just before the break. That you have this humongo gas cloud, a molecular cloud, they call them. And it'll break into bits. And these are typically stars, but some might not be stars. In addition to that, each one of these will have a disk of material surrounding it that will then break up into little bits beyond the bits that just broke off to make the thing that had the disk.

• 20:40Speaker 02

  Hmm.

• 20:40Neil deGrasse Tyson?

  Did I understand that?

• 20:42Speaker 02

  You're doing good, yeah.

• 20:42Neil deGrasse Tyson?

  I'm doing okay.

• 20:43Speaker 02

  I will say, right, so those are the-

• 20:45Neil deGrasse Tyson?

  So two dynamic, two different kinds of phenomenon going on.

• 20:48Speaker 02

  Two different formation mechanisms.

• 20:50Neil deGrasse Tyson?

  Formation mechanism, that's the phrase I'm looking for.

• 20:52Speaker 02

  Right. And so we want to use that as definitional for saying like, what kind of object are you looking at? I'd prefer to know how it formed because can you eject these objects that form around a star?

• 21:06Neil deGrasse Tyson?

  Yeah, you do.

• 21:06Speaker 02

  Oh, 100% you do.

• 21:08Neil deGrasse Tyson?

  Yeah.

• 21:09Speaker 02

  They're launched off, we probably ejected stuff all sorts of ways when we formed our-

• 21:12Neil deGrasse Tyson?

  We might have like 30 planets or something at the beginning.

• 21:15Speaker 02

  Yes, yes, exactly.

• 21:16Neil deGrasse Tyson?

  And now we're down to eight? Get over it. And so all those would be rogue planets by now.

• 21:21Speaker 02

  Rogue worlds.

• 21:22Neil deGrasse Tyson?

  Or eaten.

• 21:23Speaker 02

  Rogue worlds, I like rogue worlds rather than planets, just because-

• 21:26Chuck Nice?

  Or could have any of them become joint forces to become like-

• 21:30Speaker 02

  Get picked up by another star.

• 21:31Neil deGrasse Tyson?

  Yeah, get picked up by another star.

• 21:33Speaker 02

  Yeah, so we talk about that too. That's pretty hard to do, but not impossible.

• 21:36Chuck Nice?

  Okay.

• 21:37Speaker 02

  It's possible that it could happen. Uh, they could also, they get scattered around. And we have evidence for this material now. Like, present day, we have material that has passed through our own solar system after it probably got ejected from a totally different solar system.

• 21:51Neil deGrasse Tyson?

  Nice.

• 21:51Speaker 02

  This object called Oumuamua, which is an interstellar asteroid-

• 21:57Neil deGrasse Tyson?

  Right.

• 21:57Speaker 02

  -rock that came flying through here. And that probably got dumped out when its own sun was forming its solar system. The one thing on this, though-

• 22:06Neil deGrasse Tyson?

  That ain't right, that ain't right.

• 22:07Chuck Nice?

  I know.

• 22:08Speaker 02

  Yeah, it is okay, like-

• 22:09Chuck Nice?

  Don't let the doorknob hit you, Omoa Moa.

• 22:12Speaker 02

  But don't you think-

• 22:14Neil deGrasse Tyson?

  Oh, by the way, it's Hawaiian for scout. And it's repeated, Amuramua for emphasis.

• 22:19Chuck Nice?

  Got you.

• 22:20Neil deGrasse Tyson?

  It's basically first scout.

• 22:21Chuck Nice?

  Got you.

• 22:22Speaker 02

  And it was named that because it was on a telescope, it was found through a telescope in Hawaii. The Pan-Stars Telescope, which is a wonderful telescope. And as an homage to Hawaii, they chose this wonderful name.

• 22:34Chuck Nice?

  Right.

• 22:34Neil deGrasse Tyson?

  So, so, just, I did this calculation long ago. This is the perfect time for me to invoke it.

• 22:40Chuck Nice?

  Alright.

• 22:40Neil deGrasse Tyson?

  Because how often does one get to invoke a calculation?

• 22:43Chuck Nice?

  Sweet.

• 22:43Neil deGrasse Tyson?

  If there were four bumblebees flying in the continental United States.

• 22:49Chuck Nice?

  Okay.

• 22:49Neil deGrasse Tyson?

  The chances of them accidentally bumping into each other are greater than any two stars in our galaxy.

• 22:57Speaker 02

  Ooh.

• 22:57Chuck Nice?

  Wow.

• 22:58Neil deGrasse Tyson?

  So, but if you want to talk about how empty space is between stars.

• 23:01Chuck Nice?

  That's how much stuff is not there.

• 23:02Neil deGrasse Tyson?

  It's not there. So, if you have rogue things cast off, there's still the unlikelihood that you would even come into the vicinity of another star. But even if you did, you're gonna have a velocity that's hard to trap.

• 23:15Chuck Nice?

  Suppose.

• 23:16Neil deGrasse Tyson?

  So, Amuramua had hyperbolic velocity, so we're not, it's coming through and it's not even looking back.

• 23:21Chuck Nice?

  Right.

• 23:21Speaker 02

  No, it has nothing to do with us. Right, like, we didn't capture it, we're not doing anything with it.

• 23:25Neil deGrasse Tyson?

  We're not doing a damn thing doing it.

• 23:26Speaker 02

  It just, it came through, like, beep beep, here I come, there I go. And even looking at its motion, uh, its velocity.

• 23:34Chuck Nice?

  Yeah.

• 23:34Speaker 02

  It looked like maybe we were its first pass, possibly. This is very hard to tease out, but there was a paper on that, whether or not we were the first.

• 23:41Neil deGrasse Tyson?

  A research paper, yeah.

• 23:41Speaker 02

  A research paper that was looking at whether or not we were its first encounter after it departed. And we traced, astronomers tried to trace it back and see where it might have come from.

• 23:51Chuck Nice?

  Right, so now, with that in mind, did, we're the first pass, did we alter its course?

• 23:58Speaker 02

  Oh, great question, Chuck. Uh, I don't know, maybe, probably a little bit.

• 24:03Neil deGrasse Tyson?

  Oh, yeah, yeah, yeah, it feels, yeah, you can, you can, you can, you cannot get captured, but still feel what's going on here.

• 24:09Chuck Nice?

  Okay.

• 24:10Neil deGrasse Tyson?

  Oh, yeah, yeah, so if you, if you look at, they have the trajectory.

• 24:13Speaker 02

  Oh, yeah, yeah, yeah, yeah, yeah.

• 24:14Neil deGrasse Tyson?

  And the trajectories arc.

• 24:15Speaker 02

  Right.

• 24:15Neil deGrasse Tyson?

  In response to the gravity of Jupiter and the Sun.

• 24:18Chuck Nice?

  Interesting.

• 24:18Speaker 02

  But when you put enough of a change in the velocity that when it gets to the next star, it's really obvious, like, oh, this is its next stellar encounter. I'm not sure we can tease it out quite yet, because it still looks like a disk, it's like a disk object. Just sort of flying around in the disk of the Milky Way.

• 24:37Chuck Nice?

  Nice.

• 24:38Speaker 02

  Beep beep.

• 24:39Neil deGrasse Tyson?

  What's that, the, um, the Jetsons?

• 24:41Chuck Nice?

  Oh.

• 24:41Neil deGrasse Tyson?

  No, the Jetsons.

• 24:42Chuck Nice?

  Oh, flying, uh, the flying cars.

• 24:43Neil deGrasse Tyson?

  Yeah, yeah, yeah.

• 24:44Speaker 02

  Oh, I thought you were doing beep beep from the Roadrunner.

• 24:46Neil deGrasse Tyson?

  That's before your time, sorry.

• 24:50Speaker 02

  Maybe.

• 24:50Chuck Nice?

  She's like, okay.

• 24:51Speaker 02

  Okay.

• 24:51Neil deGrasse Tyson?

  Yeah, Jetsons were so before everybody's time.

• 24:55Speaker 02

  I watched it when I was a kid, so I don't know why it's before me.

• 24:57Neil deGrasse Tyson?

  The Roadrunner did a beep beep too.

• 24:59Chuck Nice?

  Yes, he did.

• 24:59Speaker 02

  Yeah.

• 25:00Neil deGrasse Tyson?

  You don't just learn recently, but this had nothing to do with anything. The Roadrunner never left the road.

• 25:07Chuck Nice?

  How about when he was standing on air and the coyote would fall?

• 25:10Neil deGrasse Tyson?

  No, the coyote's standing on air. The Roadrunner isn't.

• 25:13Chuck Nice?

  That's true.

• 25:14Speaker 02

  Oh, huh.

• 25:15Chuck Nice?

  Interesting.

• 25:16Neil deGrasse Tyson?

  Yeah, the Roadrunner stops before it gets to the edge of the cliff. And it's always on the road.

• 25:20Speaker 02

  That's interesting.

• 25:21Neil deGrasse Tyson?

  Hence, the Roadrunner.

• 25:22Speaker 02

  Yeah, I have another point on stellar flyby. I wanted to just pull us back in here, Neil. So, you might-

• 25:29Neil deGrasse Tyson?

  You don't like my pop culture references? I'm sorry.

• 25:31Speaker 02

  I do, I love it, I love it, I love it, I love it, it's so great. Um, but, the, one of the things that I think is massively, uh, interesting right now in astronomy is how many times stars not run into each other, but interact with one other. So the issue of, and this is, this is my new thing, I'm really into the new villain of planetary architecture, is the stellar flyby. The unappreciated, um, influence that stars that move by each other can have. And the reason why I say that-

• 26:04Neil deGrasse Tyson?

  Flyby looting.

• 26:06Speaker 02

  Flybys that will change the core, the, change the structure of maybe your planetary system, or now, like, okay, so the question, I think, had something to do with what we're understanding about exoplanets and, and learning about it in the future. So, here's one for everybody. In one million years, just about one million, it's like 1.1 million years.

• 26:26Neil deGrasse Tyson?

  Okay, let me put, put that on my, on my calendar.

• 26:28Speaker 02

  I don't, I can't give you the exact date.

• 26:30Neil deGrasse Tyson?

  October 12th, October 12th, one million years.

• 26:32Speaker 02

  Plus or minus like 10,000 years, yes. But, um, but, there will be a stellar flyby, so, at its closest encounter, by a star that's smaller than our own sun, but we're headed for each other. And in one million years, it's gonna pass within our Oort Cloud. It's coming straight in.

• 26:51Neil deGrasse Tyson?

  So the Oort Cloud, the outer region of comets, that's a spherical zone. Very distant, but very there.

• 26:57Speaker 02

  Very there, with lots of material.

• 27:00Neil deGrasse Tyson?

  Yeah, this is like, uh, trillions of comets, just- Okay, that sounds- Just waiting to strike. I was gonna say, that sounds catastrophic.

• 27:08Speaker 02

  It's, I, it's, it's, we've looked at it.

• 27:14Speaker 02

  Astronomers have looked at it to see, like, is the dun- you know, is it gonna be a disaster? Uh, and the conclusion is, it's uncertain, but the impact that it'll have on the Oort Cloud might not be super bad.

• 27:26Neil deGrasse Tyson?

  Jan Ort was the Dutch astronomer who first calculated the existence of the Oort Cloud. It's so far away, you can't see the objects that, at that distance. But when they come in, you see them near the sun and you look at their trajectory. And you say, oh, this much terminate way out at this distance before it comes back again. The calls are coming from inside the house. Okay.

• 27:47Speaker 02

  But like, so-

• 27:51Speaker 02

  So if you think about it, the Oort Cloud actually stretches a third of the way to the closest star.

• 27:56Neil deGrasse Tyson?

  Mm-hmm.

• 27:57Speaker 02

  A third of the way.

• 27:58Neil deGrasse Tyson?

  Wow.

• 27:59Speaker 02

  It gets loose. So, I mean, think about that, you know, I mean, you get something that flies between us and that, uh, that next closest object, it loosens up things.

• 28:08Neil deGrasse Tyson?

  Because they've only barely held on to begin with.

• 28:11Speaker 02

  Barely held on.

• 28:12Neil deGrasse Tyson?

  So any disturbance will completely-

• 28:14Speaker 02

  Right.

• 28:14Neil deGrasse Tyson?

  Yeah, wreak havoc.

• 28:15Speaker 02

  And most important here is the consideration of, we're constantly doing mission planning. Like, what are the next stages of mission planning, right?

• 28:22Neil deGrasse Tyson?

  And what's the, what's the name of the star, just so I know?

• 28:23Speaker 02

  So, I, it's Gliese 780, 780.

• 28:26Neil deGrasse Tyson?

  Okay.

• 28:27Speaker 02

  It's a, it's one of these names that, um, I constantly mix it with 780 versus 781, I think. So, as my fear of-

• 28:34Neil deGrasse Tyson?

  As do we all. Gleason 7? No, no. Not Gleason?

• 28:38Speaker 02

  Yeah.

• 28:39Neil deGrasse Tyson?

  G L E I S E?

• 28:41Speaker 02

  E S.

• 28:42Neil deGrasse Tyson?

  Gle.

• 28:43Speaker 02

  G L I E S E.

• 28:44Neil deGrasse Tyson?

  E S E. It's a catalog of, uh, it's high, high-moving, fast-moving stars, right?

• 28:49Speaker 02

  Close, bright, so they're mostly fast-moving.

• 28:52Neil deGrasse Tyson?

  Yeah, yeah. Fast-moving, uh, in our field of view. So, in order for that to be the case, they have to be nearby. So... Man, I was hoping it was Gleason. No.

• 29:03Speaker 02

  No, unfortunately, no.

• 29:04Neil deGrasse Tyson?

  But just to be clear- Norton! So this is not a catalog of stars that are actually moving fast. It's a catalog of stars that are moving fast in our field of view. So you can have a bird fly by in front of you- Mm-hmm. And it, and it, that's going maybe 20 miles an hour, and a plane- That's moving past your field of view much more slowly.

• 29:25Chuck Nice?

  Right.

• 29:26Neil deGrasse Tyson?

  And you're not gonna say.

• 29:28Chuck Nice?

  That the bird is going faster than a plane.

• 29:29Neil deGrasse Tyson?

  The bird is not going 600 miles an hour.

• 29:31Chuck Nice?

  Right.

• 29:31Neil deGrasse Tyson?

  Right, so that angle matters. And that angle manifests by its distance. So, uh, there's a catalog of selected for their, for their fast movement in our night sky. And those tend to be the nearest objects.

• 29:45Speaker 02

  Yeah, right, because we're detecting them. And so that one had been known, we've known about that star for a really long time. It's a bright, it's a very bright star. And it's, it's, it's.

• 29:53Chuck Nice?

  It's headed for us.

• 29:54Speaker 02

  We are headed for it, it's heading for us. And just think about it, it's probably got a solar system around it. And an Oort cloud, and a Kuiper belt. Why not?

• 30:04Chuck Nice?

  Why, why wouldn't it?

• 30:04Speaker 02

  Probably the majority of stars, why wouldn't they have them? And so when you say, I've got all of my, every time I give a science talk, I bring this up. But don't you wanna, we'll, we're gonna see it.

• 30:15Chuck Nice?

  Totally wanna get in it.

• 30:16Speaker 02

  Like, bring it here.

• 30:18Neil deGrasse Tyson?

  Well, wait, that means Oort clouds will intersect.

• 30:20Speaker 02

  More than that, yes. The Oort clouds, the Kuiper belts, possibly like whatever, whatever this thing's got around it. We could fly something to it. There's a lot of this discussion about going to Proxima Centauri. Because we all wanna get there like now, while we're all still alive. Please, 78, man, let's go.

• 30:36Neil deGrasse Tyson?

  That's gonna be even closer when it's close.

• 30:37Speaker 02

  It's gonna be so close.

• 30:39Neil deGrasse Tyson?

  She sounded like she's like ready to.

• 30:41Chuck Nice?

  I was gonna say, and I am so ready to do this 1 million years from now.

• 30:45Neil deGrasse Tyson?

  She's fucking like, she's got her telescope all ready for it.

• 30:48Speaker 02

  This is very sad, because I'll be dead.

• 30:49Neil deGrasse Tyson?

  You better take them longevity pills before that happens.

• 30:52Chuck Nice?

  No, by then we'll be able to upload your consciousness to a computer.

• 30:55Speaker 02

  That'll be so nice. That's good.

• 30:57Chuck Nice?

  Yeah.

• 30:58Speaker 02

  I'd like to see it when it happens.

• 30:59Chuck Nice?

  Cool.

• 31:00Neil deGrasse Tyson?

  Chuck, what else you got?

• 31:01Chuck Nice?

  All right, so, okay. This is, let's go for a quick one, because I know we're running out of time in this segment. This is from Ross King.

• 31:08Neil deGrasse Tyson?

  You can do a long one and then I tease the next segment, dude. This is how I do this.

• 31:12Chuck Nice?

  Well, you know, if we keep discussing this like this, we'll be able to do it with this short one.

• 31:17Neil deGrasse Tyson?

  Go.

• 31:20Chuck Nice?

  No, this is Rossi King from YouTube. Uh, actually, I just wanted to ask this for myself, too. Was Jupiter a failed star? And then the person says, "I'm really glad it failed, because I love it in the nighttime sky."

• 31:31Neil deGrasse Tyson?

  Oh, my God. How cute is that? That should be a quick answer.

• 31:34Chuck Nice?

  Yeah, but is Jupiter a failed star? Which, you know, yeah.

• 31:37Speaker 02

  Yeah, yeah, no, uh, uh, it's not. No, the quick answer to that would be no. But again, let's not call them failed stars. Let's just call them the one.

• 31:47Neil deGrasse Tyson?

  Achieving planets?

• 31:49Speaker 02

  I call them overexcited planets. Thank you.

• 31:52Neil deGrasse Tyson?

  Overachieving planets?

• 31:53Speaker 02

  I'm not kidding, Neil. This is my coined term.

• 31:56Neil deGrasse Tyson?

  This is very modern teacher lingo, right?

• 31:59Speaker 02

  Overexcited planets. That's what I sometimes call them, but then I don't like planets.

• 32:02Chuck Nice?

  Don't star shame me. Don't star shame me.

• 32:06Speaker 02

  Love it, you guys are going with it.

• 32:07Chuck Nice?

  I'm not a failed star.

• 32:09Speaker 02

  Exactly. Jupiter shouldn't feel any, in any way, shape, or form like it is.

• 32:13Chuck Nice?

  Inadequate.

• 32:14Speaker 02

  Exactly.

• 32:15Chuck Nice?

  Right.

• 32:15Speaker 02

  It is a behemoth of our solar system.

• 32:18Chuck Nice?

  Yes.

• 32:18Speaker 02

  Many times, I say, if I'm gonna find an Earth-like planet, uh, that I'll be comfortable saying, yes, let's, let's consider that habitable. I want a Jupiter at a Jupiter radius away. Because you know what Jupiter does for us? It protects us in a lot of ways. It's the bouncer of the solar system. It's the one that's like taking hits for us because asteroids get dumped in and comets are coming in. And what does Jupiter do? It takes a lot of hits. Sure, it deflects some of them our way.

• 32:44Chuck Nice?

  Mm-hmm.

• 32:45Speaker 02

  Let's not talk about that part.

• 32:46Chuck Nice?

  Right.

• 32:46Speaker 02

  But unless you want to. But I would say.

• 32:49Neil deGrasse Tyson?

  But most of what it does is protect us.

• 32:52Speaker 02

  It's a protector. So I'd really like to see if we find an object.

• 32:56Neil deGrasse Tyson?

  The bouncer of the solar system.

• 32:57Chuck Nice?

  ID please.

• 32:58Neil deGrasse Tyson?

  Standing out there. ID please.

• 33:00Speaker 02

  Right. That's what it says to all the comets as they come in, like, nope.

• 33:04Neil deGrasse Tyson?

  ID includes what your trajectory is.

• 33:06Chuck Nice?

  Yeah, there you go.

• 33:06Neil deGrasse Tyson?

  Trajectory, please.

• 33:07Chuck Nice?

  Right.

• 33:08Neil deGrasse Tyson?

  Right, no, no, that ain't happening. Keep walking, so.

• 33:11Speaker 02

  So I would not call it a failed star. I'd call it the bouncer of the solar system. The most important of the planets for Earth to consider right now.

• 33:18Neil deGrasse Tyson?

  So how much more mass would it need? For it to have ignited a core of energy.

• 33:23Chuck Nice?

  Or not even a core, for it to not have ignited a core of energy.

• 33:27Speaker 02

  Well, this is-

• 33:28Chuck Nice?

  And become the overachieving planet.

• 33:30Speaker 02

  Right, so the brown dwarf regime is roughly the lower mass bound that we call is about 13 times the mass of Jupiter, but that not a great number. That was a traditional number that was used.

• 33:43Neil deGrasse Tyson?

  About a factor of 10.

• 33:44Speaker 02

  And, right, and the reason is because at that mass, you can get heavy hydrogen burning, or deuterium burning. And so because that tended to be a definitional thing, where either the difference between a star and a brown dwarf is hydrogen burning, nuclear burning, and then it was kind of capped at the bottom end of like, well, at about 13 Jupiter masses, then it's deuterium burning that stops. And so boom, that was the definition, and it's terrible.

• 34:11Neil deGrasse Tyson?

  So the way to think about it is just if Jupiter had more than 10 times its current mass, it would start entering the brown dwarf regime.

• 34:18Speaker 02

  Yeah, it would be a massive-

• 34:19Neil deGrasse Tyson?

  Okay.

• 34:20Speaker 02

  -thing.

• 34:20Neil deGrasse Tyson?

  But something about Jupiter, however, that Jupiter be proud, I think, is that it is emitting more energy than it is receiving from the sun.

• 34:27Speaker 02

  Yes.

• 34:28Neil deGrasse Tyson?

  So it is a net energy generating object in this solar system.

• 34:31Chuck Nice?

  It's like a blue state. Sorry, that was, that was very full of a club.

• 34:38Speaker 02

  It was.

• 34:38Chuck Nice?

  I'll fill in those details after this break, when StarTalk continues, the world between planets.

• 34:54Chuck Nice?

  Hey, we'd like to give a Patreon shout out to the following Patreon patrons, Joe Aguirre, or maybe Joe pronounces it Aguirre, Daniel Hargrove, and Jill Berkey. Guys, thanks so much for your support of StarTalk through Patreon, because without you, it'd be a lot more difficult to make this show. And if you would like to have your name shouted out as a Patreon patron, please go to patreon.com/startalkradio and support us.

• 35:25Speaker 03

  Bringing space and science down to earth. You're listening to StarTalk.

• 35:41Neil deGrasse Tyson?

  We're back on StarTalk. Cosmic Queries, the worlds between planets and stars. And we have one of the world's experts. Yes. On that, Jackie Farren. One of my colleagues, she's my colleague. Right, yes. Well, while I'm sitting here, I can be her colleague while I'm here. Yes, exactly. No, we get comedians here that are your colleagues. If I get one of my people, she's my colleague. Somehow I lose in this deal.

• 36:08Neil deGrasse Tyson?

  So we were talking about Jupiter as not a failed star, but an overachieving planet. But still, it's a factor of 10 in mass away from having turned on as a star. So that's still kind of far away. It's not kissing the door, you know, kissing the boundary there, right? Factor 10.

• 36:23Speaker 02

  No, yeah. It's in squarely in the, we're totally comfortable calling it a planet object. It'd have to be quite a bit more massive before we start to feel awkward. There are other systems. There's one called HR8799, the name of the star. And it has-

• 36:39Neil deGrasse Tyson?

  Again, named for the catalog out of which they come, yeah.

• 36:41Speaker 02

  Right. And these stars also have multiple names, but that's the most popular of the names. I often call that system-

• 36:48Neil deGrasse Tyson?

  Because that's the catchiest name. HR8799? That's the most popular. That one just, yeah, it just rolls off the tongue. That's like the share of-

• 37:00Speaker 02

  HR8799. So I sometimes call HR8799 the Brad Pitt of planetary systems that have been directly imaged. Because if you have a camera, AKA a chronograph or an adaptive optic system for astronomy-

• 37:11Neil deGrasse Tyson?

  Special camera for this, yeah?

• 37:12Speaker 02

  Yeah, we point it at HR8799 because it's so pretty.

• 37:18Neil deGrasse Tyson?

  Nice.

• 37:19Speaker 02

  The system. And you can image four, one, two, three, four planets orbiting-

• 37:25Neil deGrasse Tyson?

  In one fell swoop.

• 37:26Speaker 02

  Yeah, and I would highly recommend for your, um, for your listeners-

• 37:30Neil deGrasse Tyson?

  Does Brad Pitt know this?

• 37:32Speaker 02

  I have said it so much, I hope so.

• 37:34Neil deGrasse Tyson?

  Okay.

• 37:34Speaker 02

  And that I'd like him to just feel like the honor of the Brad Pitt status of planetary systems. HR8799, he could just call himself the HR8799 of, uh-

• 37:45Neil deGrasse Tyson?

  Of Hollywood. I'm Hollywood's HR8799, baby.

• 37:49Speaker 02

  Switch it up.

• 37:49Neil deGrasse Tyson?

  So, you know, just so- Point a camera at me. The year. I was the sexiest astrophysicist alive.

• 37:56Chuck Nice?

  Okay.

• 37:56Neil deGrasse Tyson?

  This is 40 pounds ago, by the way.

• 37:59Chuck Nice?

  I love that we are now measuring chronology in pounds.

• 38:02Neil deGrasse Tyson?

  That year Brad Pitt was the cover as Sexiest Man Alive.

• 38:06Chuck Nice?

  Cute.

• 38:06Neil deGrasse Tyson?

  Beyond category. He didn't have to be in a category in order to, but he had no category.

• 38:11Speaker 02

  What year is this?

• 38:14Speaker 02

  I want to link it to H8888.

• 38:17Neil deGrasse Tyson?

  Next time, next question.

• 38:20Speaker 02

  Don't want to answer it.

• 38:21Chuck Nice?

  That was great.

• 38:22Neil deGrasse Tyson?

  Next question.

• 38:22Chuck Nice?

  All right, so I have a question personally that I just, I'm thinking now and I just, I can't stop thinking about it. As you were talking about these formation mechanisms, what, what I want to know is, is it possible to have those two formation mechanisms happen simultaneously? So, I'm sorry, the three formation mechanisms happen simultaneously? So that you have that star that's being surrounded by a brown dwarf and planets?

• 38:59Speaker 02

  Yes.

• 38:59Chuck Nice?

  Can that happen?

• 39:00Speaker 02

  So you're asking a question that basically got asked at a seminar the other day. I ask it all the time and the result would be, uh, is it possible that you can form a brown dwarf?

• 39:12Chuck Nice?

  Yeah.

• 39:12Speaker 02

  What this thing is that we call a brown dwarf? These objects that have deuterium burning and they're formed through the process of fragmentation of a giant molecular cloud? And you can make that same kind of object deuterium burning through the accretion process or gravitational fragmentation around a star?

• 39:29Chuck Nice?

  Right.

• 39:30Speaker 02

  And so can you get, if you're going to count up all the objects? You would see at a certain mass, you would start to get more of the object because you're forming them two different ways. And so you would see a higher number of objects popping out as you get down to like, maybe it's at 10 Jupiter masses. Maybe it's at 12, maybe it's at four, whatever it is, because you're doubling down on how you form them.

• 39:57Neil deGrasse Tyson?

  On the mechanism.

• 39:58Speaker 02

  Yes, you would double the number, double, maybe triple, maybe quadruple, or maybe just a little bit more. But we're looking for this exact thing, for counting up the numbers we get and then seeing if there's any signature.

• 40:10Neil deGrasse Tyson?

  I take it back. I take it back.

• 40:12Speaker 02

  Pretty good. Pretty good.

• 40:13Chuck Nice?

  Well, thanks.

• 40:14Speaker 02

  Yes, a hundred percent.

• 40:15Chuck Nice?

  All right, cool.

• 40:16Neil deGrasse Tyson?

  I take it back, Chuck.

• 40:17Chuck Nice?

  Excellent.

• 40:17Neil deGrasse Tyson?

  So Chuck, this is our final segment. We gotta go into like lightning round now.

• 40:20Chuck Nice?

  All right, let's move into our lightning round.

• 40:23Speaker 02

  That was a bell.

• 40:24Chuck Nice?

  Okay.

• 40:25Neil deGrasse Tyson?

  Go Chuck.

• 40:26Chuck Nice?

  This is such a fascinating.

• 40:27Neil deGrasse Tyson?

  So Jackie, your answer has to be.

• 40:28Speaker 02

  How many seconds?

• 40:29Neil deGrasse Tyson?

  We're testing your soundbititude.

• 40:31Speaker 02

  Got it.

• 40:31Neil deGrasse Tyson?

  Okay.

• 40:32Speaker 02

  Ready.

• 40:32Neil deGrasse Tyson?

  All right, go Chuck.

• 40:33Chuck Nice?

  Okay. This is Kristin Davies and Kristin says, I'm a seventh grade science teacher in Ohio and I asked my students for their questions on the topic today. My students and I enjoy listening to clean episodes of StarTalk. Okay, now you see why I'm reading this?

• 40:46Neil deGrasse Tyson?

  Episodes that don't have Chuck in them.

• 40:47Chuck Nice?

  Yeah, that's what I'm saying. Thanks a lot, Kristin. Yeah, but I'm the one reading your question, Kristin. Just remember that. During our study times, I listen to other episodes on my commute to work and that gets me pumped up. So here's what she says.

• 41:01Chuck Nice?

  From the student, how many stars are in the universe? Has anyone ever counted them and is it possible? Another student says, can you turn a planet into a star? One and two questions.

• 41:10Neil deGrasse Tyson?

  Okay, first question, go.

• 41:12Speaker 02

  All right, so number of stars in the universe.

• 41:14Chuck Nice?

  Universe.

• 41:15Speaker 02

  That number is insane. Number of stars in the galaxy, we're gonna go with 200 billion probably. And so then there's billions and billions of galaxies. That's why I'm saying. Too, too large for me to give the exact number. Second question, can you turn a planet into a star? Awesome question. People are trying to figure this out. Unlikely because you dump enough material onto it. It probably gets fatter and you probably can't ignite unless you do a gigantic dump from something that happened.

• 41:42Chuck Nice?

  Fantastic.

• 41:43Neil deGrasse Tyson?

  But we can do a quick, Jackie, we can do the calculation.

• 41:45Speaker 02

  Yeah.

• 41:45Neil deGrasse Tyson?

  If, for the, for the number of stars. If you, if you just say our galaxy has like 100 billion stars, let's say.

• 41:51Speaker 02

  200, let's go with 200 billion.

• 41:52Neil deGrasse Tyson?

  But it's factor two between friends.

• 41:54Speaker 02

  Yeah, yeah, sure, okay.

• 41:55Neil deGrasse Tyson?

  So, and to keep the math simple, 100 billion stars.

• 41:58Chuck Nice?

  Okay.

• 41:58Neil deGrasse Tyson?

  And there's somewhere between 10 and 100 billion galaxies in the observable universe. So 100 billion times 100 billion, that's 10 to the 21st power.

• 42:10Chuck Nice?

  Okay, there you go.

• 42:11Speaker 02

  What do you call that?

• 42:12Neil deGrasse Tyson?

  That's one sextillion.

• 42:14Speaker 02

  Sextillion.

• 42:15Chuck Nice?

  That's a sextillion?

• 42:16Neil deGrasse Tyson?

  Sextillion.

• 42:17Chuck Nice?

  That seems very small.

• 42:19Neil deGrasse Tyson?

  Uh, well, let's do it. So a billion is, stay with me, nine zeros is a billion.

• 42:23Chuck Nice?

  Right.

• 42:24Neil deGrasse Tyson?

  Trillion.

• 42:25Chuck Nice?

  Okay.

• 42:25Neil deGrasse Tyson?

  Count the zeros, it's 12.

• 42:26Chuck Nice?

  10, right?

• 42:27Neil deGrasse Tyson?

  12.

• 42:28Chuck Nice?

  Okay.

• 42:28Neil deGrasse Tyson?

  Units, three zeros at a time.

• 42:30Chuck Nice?

  Cause it would have been 100 billion.

• 42:31Neil deGrasse Tyson?

  Start again, okay?

• 42:32Speaker 02

  Okay.

• 42:32Chuck Nice?

  So 12 trillion.

• 42:34Neil deGrasse Tyson?

  It's a trillion. 15 quadrillion.

• 42:36Chuck Nice?

  Quadrillion.

• 42:38Neil deGrasse Tyson?

  18. Quintillion. Twenty-one.

• 42:42Chuck Nice?

  Sex. Right.

• 42:44Neil deGrasse Tyson?

  Yeah. So that's all I'm saying.

• 42:45Speaker 02

  Yeah.

• 42:46Neil deGrasse Tyson?

  Yeah, so about a sextillion stars.

• 42:47Chuck Nice?

  No, but I'm saying, when I say that seems small, I mean, it seems small for the-

• 42:50Neil deGrasse Tyson?

  Sextillion is small to you?

• 42:51Chuck Nice?

  Yeah.

• 42:52Neil deGrasse Tyson?

  No! Plus, plus-

• 42:53Speaker 02

  I mean, it's big. That's a number I don't say, because it's just so big.

• 42:57Neil deGrasse Tyson?

  It's just too crazy big.

• 42:58Chuck Nice?

  No, I'm talking about, I'm talking about when you, from where we're starting. I, I think, because you said it's only a hundred billion.

• 43:05Neil deGrasse Tyson?

  In our own galaxy.

• 43:06Speaker 02

  In our galaxy.

• 43:07Chuck Nice?

  Oh, okay. All right, forget it then.

• 43:09Neil deGrasse Tyson?

  Plus, plus, plus, if, if there's not a sextillion stars in the galaxy, then there's two sextillion.

• 43:16Chuck Nice?

  Right.

• 43:16Speaker 02

  Yeah.

• 43:17Neil deGrasse Tyson?

  At those numbers, these factors of one and two-

• 43:19Chuck Nice?

  They don't make a difference. They make no difference.

• 43:20Neil deGrasse Tyson?

  You want to get the sense of the scale of this more than you want to-

• 43:22Chuck Nice?

  But you still can't get the sense of that scale.

• 43:23Speaker 02

  But one other thing-

• 43:24Neil deGrasse Tyson?

  And not all galaxies are our size. There's a lot of small, small and big ones, yeah.

• 43:28Speaker 02

  No, there's small ones, there's bigger ones. Uh, there's collide galaxies that have merged and come together. But another thing they asked about counting the number of stars, and there is this survey called, the, um, it's a European survey, it's called Gaia, and counting. They have, they're called the Billion Star Survey. One point seven billion stars, and that's, that's huge.

• 43:48Neil deGrasse Tyson?

  Those are not extrapolated. They're actually counting-

• 43:51Speaker 02

  Counted.

• 43:51Chuck Nice?

  They've counted a billion stars.

• 43:53Speaker 02

  Measured their distances, how far away they are. It's the greatest map that humans have ever produced.

• 43:58Neil deGrasse Tyson?

  One point seven billion-

• 44:00Speaker 02

  Billion. Billion.

• 44:01Neil deGrasse Tyson?

  Objects in a catalog.

• 44:02Speaker 02

  That's like a drop the mic moment.

• 44:04Chuck Nice?

  Yeah.

• 44:04Speaker 02

  I can't do that here. Okay, you did.

• 44:07Chuck Nice?

  Oh, okay, he did it. I was gonna say, please don't let that hit the ground.

• 44:09Speaker 02

  Neil dropped the mic for Gaia.

• 44:11Neil deGrasse Tyson?

  Excellent. Next.

• 44:12Chuck Nice?

  Okay.

• 44:12Neil deGrasse Tyson?

  Keep it moving. Oh, hey, go.

• 44:14Chuck Nice?

  There we go. All right, this is from Twitter, and this is, um, Aksh, Ak, Aksh, Akshat says this. I think that's the name, whatever, who cares. How do astronomers study-

• 44:26Neil deGrasse Tyson?

  Akshat cares.

• 44:26Chuck Nice?

  Akshat, Akshat probably cares. How do astronomers study the atmospheres of brown dwarfs? And how do we even detect them?

• 44:37Speaker 02

  Yeah, that's exactly what I do for a living.

• 44:39Chuck Nice?

  Yeah.

• 44:40Speaker 02

  And the way that we detect it is directly, so that's the actual method that we call it.

• 44:45Neil deGrasse Tyson?

  You can do that for a living?

• 44:46Speaker 02

  Yeah.

• 44:47Chuck Nice?

  I know.

• 44:47Neil deGrasse Tyson?

  Isn't that?

• 44:47Chuck Nice?

  That's a great thing to say.

• 44:49Neil deGrasse Tyson?

  Just a moment, just a moment.

• 44:51Speaker 02

  Oh.

• 44:52Chuck Nice?

  Let's all hold hands, yes.

• 44:53Neil deGrasse Tyson?

  Meditative moment, okay?

• 44:55Chuck Nice?

  It is a wonderful thing that you can do that for a living.

• 44:59Speaker 02

  Yeah.

• 45:00Neil deGrasse Tyson?

  Okay, go.

• 45:00Speaker 02

  Yeah, I also say the tagline for astronomers, though, is unlocking the secrets of the universe for a living. Like, that's a good tagline, right? You know? I mean, sure, studying the atmospheres of a brown dwarf sounds good, too, but unlocking the secrets of the universe.

• 45:12Neil deGrasse Tyson?

  Okay, remember, we're in lightning round, so go.

• 45:14Speaker 02

  I know, sorry. Direct imaging is the technique that we use. And I basically take a telescope, I point it directly at the object. For the most part, I have to use infrared instruments, though. So, a wavelength of light that you can't see with your eye. A wavelength that's a bit longer than the radiation that we all give off, the heat that we give off. And I'll take it and I'll take the light, I pass it through a spectrograph, and I look at what it's made, what is the chemical composition? What kinds of lines do I see? And mostly, it's molecular features.

• 45:44Neil deGrasse Tyson?

  Molecules.

• 45:45Speaker 02

  Molecules.

• 45:45Neil deGrasse Tyson?

  All right, cool.

• 45:46Chuck Nice?

  All right, excellent.

• 45:46Neil deGrasse Tyson?

  Mm-hmm.

• 45:48Chuck Nice?

  There we go.

• 45:49Neil deGrasse Tyson?

  Keep going.

• 45:50Chuck Nice?

  This is Tom Cat. Thank you, Tom. Tom Cat wants to know this: Do brown dwarfs have surfaces? Or are they just balls of hot gas?

• 45:58Neil deGrasse Tyson?

  Go.

• 45:59Speaker 02

  Yeah, that is, we're often asked this, and there's no surface for you to stand on, similar with Jupiter and Saturn, you're not going there and standing and having a really nice time.

• 46:09Chuck Nice?

  Yeah.

• 46:09Speaker 02

  No, we study-

• 46:10Chuck Nice?

  They call them gas giants, right?

• 46:11Speaker 02

  Yeah, gas giants. And so brown dwarfs are souped-up gas giants.

• 46:13Chuck Nice?

  Okay.

• 46:14Speaker 02

  Very similar to Jupiter.

• 46:16Neil deGrasse Tyson?

  So there's no point, deep enough where it's dense enough that you can call it a surface?

• 46:18Speaker 02

  There might be, we don't know.

• 46:19Neil deGrasse Tyson?

  You just don't want to go? You don't even want to test it?

• 46:22Speaker 02

  You'll die, we all die, right?

• 46:24Chuck Nice?

  That's hilarious.

• 46:25Speaker 02

  But could they have some sort of core similar to Jupiter or Saturn, which would have some sort of core? Very well, it could have that. We don't know yet, though.

• 46:32Chuck Nice?

  Excellent. This is-

• 46:36Chuck Nice?

  Ooh, Louis Giovanni. Louis Giovanni says this. How do we know what a planet is made of? And if it has an atmosphere, if it goes by how much light passes through or by it?

• 46:52Speaker 02

  So that sounds like they're asking about the transit method.

• 46:55Chuck Nice?

  Pretty much.

• 46:56Speaker 02

  One of the ways that we detect planets is by looking at the planet pass in front of its host star, between your eyeball and that host star. And there's, there's lots of methods that astronomers have developed to look at the light of the star very, very carefully and see if there's any change in it as they are suspecting the transit is happening. You have to have the timing down, like smack down, to when that transit is happening, you look right at the star and you can see what it's made of. This is very complicated.

• 47:24Neil deGrasse Tyson?

  We see what the atmosphere of the planet, the transiting planet is made of.

• 47:27Speaker 02

  Right.

• 47:28Neil deGrasse Tyson?

  Right.

• 47:28Speaker 02

  Through the light of the host star. It's a very complicated method. Uh, my preference, just to re, re-gauge us back to brown dwarfs, is we draw upon what we do in brown dwarf science. Since we directly detect the atmospheres, we can guide any measurements that you want to make when you're trying to, uh, make detections of objects.

• 47:48Neil deGrasse Tyson?

  So you have ground truth of what the atmosphere might be for those who are looking for the transit in front of a, a much brighter star in the background.

• 47:55Speaker 02

  We are ground truth for transiting planets. Especially hot Jupiters, these objects that are pretty close in that are like Jupiter.

• 48:02Chuck Nice?

  Cool. All right, here we go.

• 48:04Neil deGrasse Tyson?

  Actually, we, I think we just ran out of time.

• 48:06Chuck Nice?

  Did we really?

• 48:07Neil deGrasse Tyson?

  Did we ran out of time.

• 48:08Chuck Nice?

  Oh, man.

• 48:08Neil deGrasse Tyson?

  Yeah, Chuck, I'm sorry about that.

• 48:10Chuck Nice?

  Okay, all right.

• 48:10Speaker 02

  That's sad. Oh, so many questions.

• 48:12Neil deGrasse Tyson?

  You know what I think we should have, we should have, put a few of those online and have Jackie answer them.

• 48:16Chuck Nice?

  Oh, that's a good idea.

• 48:17Speaker 02

  We could do that. Yeah.

• 48:18Neil deGrasse Tyson?

  I'll put in for that.

• 48:20Chuck Nice?

  It's amazing. People really are excited about brown dwarfs, man.

• 48:24Neil deGrasse Tyson?

  Into what you get paid for.

• 48:25Speaker 02

  Yeah, they get paid to do this for a living. It's a pretty good job. Pretty good job.

• 48:31Neil deGrasse Tyson?

  All right, Jackie, thanks for being on StarTalk. It's not your first rodeo with us.

• 48:34Speaker 02

  No, well, I've done All Stars with Chuck, but this is the first time we've ever done one.

• 48:38Neil deGrasse Tyson?

  Is it our first time?

• 48:39Speaker 02

  It is our first time, Neil, yeah.

• 48:41Neil deGrasse Tyson?

  Oh, so you go way back?

• 48:43Chuck Nice?

  Yeah, I'm the HR 80. I'm the HR 799.

• 48:51Chuck Nice?

  Of co-hosts.

• 48:53Neil deGrasse Tyson?

  All right, this brings this episode of StarTalk to a close. I thank my co-host Chuck Nice, my friend and colleague Jackie Farady. Thanks for coming on. And as always, I bid you to keep looking out.