SPEAKER_1: 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.
SPEAKER_1: This is StarTalk.
SPEAKER_1: I'm your host, Neil deGrasse Tyson, your personal astrophysicist.
SPEAKER_1: And today, we're going to have a Cosmic Queries edition of StarTalk with my co-host, Chuck Nice.
SPEAKER_1: Chuckie, baby.
SPEAKER_1: All right, someone slipped in between us here.
SPEAKER_2: That's right.
SPEAKER_1: I've got my friend and colleague, not only professional colleague, but museum colleague, Jackie Faherty.
SPEAKER_2: That's right.
SPEAKER_3: Jackie, in the house.
SPEAKER_2: Double house here.
SPEAKER_2: Double house.
SPEAKER_1: Jackie is one of the world's experts on the worlds that exist between planets and stars.
SPEAKER_1: Wow.
SPEAKER_1: There's not a sharp boundary there.
SPEAKER_1: You might have thought so, or maybe you never thought about it.
SPEAKER_1: She's thought about it.
SPEAKER_2: Yes.
SPEAKER_1: And she and her peeps, she's got a whole community of people.
SPEAKER_1: In fact, after we hired her, she brought other people after she came.
SPEAKER_1: So this place, the American Museum of Natural History, is one of the intellectual centers of this subject, because of this woman right here.
SPEAKER_2: That's really cool.
SPEAKER_1: Give me another one.
SPEAKER_3: I'm going to take ownership of that.
SPEAKER_2: You sure?
SPEAKER_3: We actually have a, our research group has stickers and T-shirts and we have a logo.
SPEAKER_3: We made it out of-
SPEAKER_1: Is that the logo with the subway letters?
SPEAKER_2: Yeah.
SPEAKER_2: Oh, because our subway symbols in New York City are circles with letters inside of them.
SPEAKER_1: Yes, they are.
SPEAKER_2: So what's your design there?
SPEAKER_3: So we are BDNYC, which stands for Brown Dwarfs, in New York City, research group.
SPEAKER_1: But the B train stops at this institute.
SPEAKER_2: It certainly does.
SPEAKER_2: So does the C.
SPEAKER_2: That's correct.
SPEAKER_3: B and C, there you go.
SPEAKER_1: So we solicited questions from our fan base, telling them we're gonna have the world's expert on this sort of nether world between planets and stars.
SPEAKER_1: And then in came hundreds of questions.
SPEAKER_1: Yes.
SPEAKER_3: Hundreds.
SPEAKER_1: Hundreds of questions.
SPEAKER_1: Yes.
SPEAKER_1: You've got them.
SPEAKER_2: And I've got them.
SPEAKER_1: Neither of us have seen it.
SPEAKER_2: No, you haven't.
SPEAKER_2: Not that it's a test.
SPEAKER_1: No, no, I love shows like this when I have one of my astrophysics colleagues, because then I'll have to say a thing.
SPEAKER_2: Right.
SPEAKER_1: She knows everything.
SPEAKER_1: I'm gonna go get lunch and then you tell me when you're done.
SPEAKER_3: I like that Neil saying I know everything.
SPEAKER_3: That's a nice compliment.
SPEAKER_2: Well, listen, why don't we jump into it with our first question, which is always from a Patreon patron.
SPEAKER_1: All right.
SPEAKER_2: Okay, here we go.
SPEAKER_2: This is AMZ Industries.
SPEAKER_2: Wow, we've gone corporate with Patreon patrons.
SPEAKER_1: That sounds very New York Stock Exchange-
SPEAKER_2: Tell me about it.
SPEAKER_2: AMZ says the sun is the biggest star in our solar system.
SPEAKER_2: I believe it's also the only star in our solar system.
SPEAKER_1: Keep going.
SPEAKER_2: Maybe I'm wrong.
SPEAKER_2: I'm just saying.
SPEAKER_2: Do we know a star or any other object in space or interstellar space that is bigger than our sun?
SPEAKER_1: Okay, so just see, they just mixed galaxy with solar system.
SPEAKER_2: That's what they did.
SPEAKER_1: That's all.
SPEAKER_2: Thank you.
SPEAKER_2: I'm trying to figure this out, but you got it.
SPEAKER_2: That's what they did.
SPEAKER_2: So, also to Jackie, do you believe in zodiac signs?
SPEAKER_2: Uh-huh.
SPEAKER_2: All right.
SPEAKER_3: Okay, two-fold question, both of which are interesting to answer.
SPEAKER_1: And they both sound completely unrelated to each other.
SPEAKER_3: They are unrelated to each other, I believe.
SPEAKER_2: I think one is a genuine interest in the cosmos and the other is a genuine interest in you.
SPEAKER_3: Oh, I love it.
SPEAKER_3: 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.
SPEAKER_3: Although we have searched for another object that might be maybe not a star, but one of these objects I study, a brown dwarf.
SPEAKER_2: Brown dwarf.
SPEAKER_3: That might be a companion to our own sun.
SPEAKER_3: Since it's alone, it's by itself.
SPEAKER_3: It doesn't have a partner.
SPEAKER_2: So are you-
SPEAKER_1: We have to be orbiting really far away.
SPEAKER_2: Yeah, I was gonna say, because 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?
SPEAKER_3: So I think you're going with the Planet Nine explanation.
SPEAKER_2: Okay, that's where I-
SPEAKER_3: Which is, yeah, and that's also been pulled on and is very popular right now.
SPEAKER_1: Planet Nine, not Pluto, just to be clear.
SPEAKER_2: Right, yes.
SPEAKER_1: I'm just sure we gotta be clear about it.
SPEAKER_3: And also we can discuss why that word planet is not very good in this context anyway.
SPEAKER_3: 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.
SPEAKER_3: The Kuiper Belt, which is this area of things that are left over from when the solar system formed.
SPEAKER_3: And whether or not there's something else that's well beyond that, possibly there's indications.
SPEAKER_3: Theorists certainly think that.
SPEAKER_3: But there was this nemesis hypothesis that existed several years ago.
SPEAKER_3: 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.
SPEAKER_1: The orbit is eccentric.
SPEAKER_3: Yes, orbit is eccentric.
SPEAKER_1: It's not emotionally eccentric.
SPEAKER_3: It could have been emotionally eccentric.
SPEAKER_2: Although it does spend a lot of time alone, so maybe you never know.
SPEAKER_3: Why are we giving emotions to the object?
SPEAKER_3: Like this is part of the problem.
SPEAKER_3: People put so much emotion on these objects.
SPEAKER_3: They want to feel them.
SPEAKER_1: Yeah.
SPEAKER_1: You just called the thing eccentric, that's all.
SPEAKER_3: Yes, eccentric.
SPEAKER_3: Right, so that it would have an eccentric orbit and that possibly it was every time it got into some area of the outer solar system, it would kick a bunch of stuff in towards our area and cause possibly mass extinction.
SPEAKER_1: Comets that would then hit right over there.
SPEAKER_3: Comets, asteroids.
SPEAKER_3: And so that's basically we've looked far and near and we haven't found anything.
SPEAKER_3: So possibly that's out.
SPEAKER_1: So nemesis was the proposed name if such an object existed and that would have been its name had we found it.
SPEAKER_3: Yeah, and nemesis is the idea that it's our nemesis, the Earth's nemesis, not necessarily the sun's, the Earth's because if it's gonna basically go far to-
SPEAKER_2: If it's launching crap at us.
SPEAKER_2: Salvo.
SPEAKER_3: Why would you want that?
SPEAKER_3: That would feel like your nemesis, right?
SPEAKER_2: Sure, sure, sure.
SPEAKER_3: So that, okay, so beyond that, the question's asking if there's a star that's bigger than our own sun.
SPEAKER_3: And that's like, yeah, definitely.
SPEAKER_3: There's so many.
SPEAKER_3: My favorite star in the nighttime sky is called Ada Carina.
SPEAKER_2: Ada Carina?
SPEAKER_3: You know Ada Carina.
SPEAKER_3: Ada Carina is a beauty.
SPEAKER_2: And I love the fact that it actually sounds like a pop star.
SPEAKER_3: Ada?
SPEAKER_2: Ada Carina.
SPEAKER_3: Yeah, it's in the constellation Carina.
SPEAKER_1: They make a good ice cream flavor.
SPEAKER_2: Ada Carina.
SPEAKER_1: No, no, Carina is the name of the flavor.
SPEAKER_2: And I ate a Carina.
SPEAKER_3: Wow, I wouldn't have put that in there, but okay.
SPEAKER_1: All right.
SPEAKER_3: It's in the homunculus nebula.
SPEAKER_3: Can you make that look as the homunculus nuts that somehow somebody could make that you'd put on the ice cream?
SPEAKER_3: Well, so Ada Carina is a very large star.
SPEAKER_3: We now think that it's actually two stars, a binary star system.
SPEAKER_3: We call it a luminous blue variable.
SPEAKER_3: It's this object that's very, very massive.
SPEAKER_3: And so we think it's two and so 40 to 50 times the mass of 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.
SPEAKER_1: So that's a variability you were talking about.
SPEAKER_3: Yeah.
SPEAKER_2: So let me just ask you this.
SPEAKER_2: Even though it's a body moving in front or transiting another body, how is one slightly larger than the other?
SPEAKER_2: Because they're both luminous.
SPEAKER_2: So the idea of a transit is one blocks light from the other, but if they're both glowing, what are you measuring?
SPEAKER_3: So they're not the exact same mass.
SPEAKER_3: So you'd have one that's say 60 times the mass of the sun and the other is 30 times the mass of the sun.
SPEAKER_3: There's even some hypothesis that there's a triple system in there.
SPEAKER_3: There's three, not just two.
SPEAKER_3: So I'm noting Ada Carina because I think it is just an awesome star or star system.
SPEAKER_3: But that's not the most massive.
SPEAKER_1: Oh yeah.
SPEAKER_3: Yeah, yeah, yeah.
SPEAKER_1: Yeah, we might put one on the website here.
SPEAKER_1: Yeah.
SPEAKER_3: You should.
SPEAKER_3: Because it was part of an HST legacy project.
SPEAKER_1: Hubble Space Telescope.
SPEAKER_3: Oh, sorry.
SPEAKER_3: Hubble Space Telescope, yes.
SPEAKER_2: You're in the lingo, girl.
SPEAKER_3: I'm in the lingo.
SPEAKER_1: Do the lingo thing.
SPEAKER_1: HST and elemental peak.
SPEAKER_3: Thank you, Neil.
SPEAKER_3: And it's a, so there's a lot of data on Ada Carina.
SPEAKER_3: But it's not the most massive.
SPEAKER_3: You get even more massive.
SPEAKER_3: There's 100, 200 times the mass of our own sun.
SPEAKER_3: And these are not stable systems.
SPEAKER_3: This is the stars.
SPEAKER_1: Again, we're not referring to their motions, Chuck.
SPEAKER_2: Right, exactly.
SPEAKER_1: They have eccentric stars and unstable stars.
SPEAKER_2: I like where this is going.
SPEAKER_1: We also have degenerate stars as well.
SPEAKER_1: That's another thing.
SPEAKER_1: Really?
SPEAKER_1: Yes, it's an actual kind of star.
SPEAKER_2: Okay, I can't even tell you what, forget it.
SPEAKER_2: I just, my mind immediately went to a star.
SPEAKER_1: And just for constellation weenies out there, Carina is a constellation visible primarily in the southern hemisphere.
SPEAKER_1: And it's part of a much larger constellation that used to be one piece.
SPEAKER_1: And it's the ship of the Argonauts, okay?
SPEAKER_1: Argo Novus is the ship.
SPEAKER_1: And it's just, Carina is the keel, I think?
SPEAKER_3: The keel, yeah.
SPEAKER_1: Yeah, so what they did was that constellation was way too big for the britches, so they broke it up into parts.
SPEAKER_1: So there's a compass, there's a sail, there's the hull, there's the, and so this is, it is the eta if brightest object in the constellation Carina.
SPEAKER_1: So alpha, beta, gamma, delta, epsilon, zeta, eta.
SPEAKER_1: So it'd be the seventh brightest star.
SPEAKER_3: And that's important also because it's not always the eta, because that's what it was cataloged 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.
SPEAKER_3: And it's just dumping material off, which is creating this gorgeous-
SPEAKER_3: Yes, the nebula that's around it is so unbelievably attractive to look at.
SPEAKER_3: And that's just from-
SPEAKER_1: But Chuck, it's really a crime scene.
SPEAKER_3: Just dumps of material.
SPEAKER_2: What's that?
SPEAKER_3: Yeah.
SPEAKER_1: It's really a crime scene.
SPEAKER_1: You're gonna see this gas just spilling out.
SPEAKER_2: So good.
SPEAKER_1: Like something happened down in there.
SPEAKER_3: Yeah, something bad happened.
SPEAKER_3: And something is continually bad happening.
SPEAKER_3: I mean, I would love to fly close and have a look at that thing.
SPEAKER_3: And you wouldn't want to be close as a human because there's probably a lot of really bad radiation around there.
SPEAKER_3: But man, would it be a sight.
SPEAKER_3: Because it is really pretty.
SPEAKER_2: That's very cool.
SPEAKER_3: It's got a human eye.
SPEAKER_2: So, Ada Carina.
SPEAKER_1: Yeah.
SPEAKER_1: Nice.
SPEAKER_1: Also, the sun is large enough, if you hollowed it out, you could pour a million Earths into it.
SPEAKER_2: Our sun.
SPEAKER_1: Our sun.
SPEAKER_2: Right.
SPEAKER_1: And now we're talking about stars bigger than that.
SPEAKER_2: That's right.
SPEAKER_2: And so these super massive stars, these are the ones that become black holes.
SPEAKER_2: Like, our sun couldn't become a black hole, could it?
SPEAKER_3: No.
SPEAKER_2: Our sun couldn't become a black hole.
SPEAKER_3: Not massive enough.
SPEAKER_3: But these are, these are the ones like, you look at these stars, the luminous blue variables, and then there's another kind, they're called Wolf-Rayette stars.
SPEAKER_3: So there's actually somebody here.
SPEAKER_2: Wolf-Rayette?
SPEAKER_3: Yes.
SPEAKER_3: Yes, actually debatable if it's Wolf-Rayette or Wolf-Rayette.
SPEAKER_2: So the people, did they discover this?
SPEAKER_1: Well, they first studied them in an important way.
SPEAKER_2: All right.
SPEAKER_1: And so then realized that no other stars look like those do, so they became their own category.
SPEAKER_2: Nice.
SPEAKER_1: Wolf-Rayette.
SPEAKER_1: R-A-Y-E-T.
SPEAKER_2: Okay.
SPEAKER_1: In French, you believe you don't pronounce the trailing consonant.
SPEAKER_2: Right, so Wolf-Rayette.
SPEAKER_2: Nice.
SPEAKER_2: All right, and for the second question.
SPEAKER_1: Reread that, please.
SPEAKER_2: Which is, do you believe in zodiac signs?
SPEAKER_3: So what I believe is such an interesting thing.
SPEAKER_3: 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.
SPEAKER_3: And so those are designations in the sky and it's where the sun and the planets and the moon all move, yeah.
SPEAKER_3: I don't place any significance on what people like to do in reading their astrological sign.
SPEAKER_3: I'm actually not even sure what my sign is.
SPEAKER_2: Oh wow, when were you born?
SPEAKER_3: Not totally true, I do know what it is, but I'm just.
SPEAKER_1: But you don't think about it or care about it.
SPEAKER_3: I don't think about it too much.
SPEAKER_1: Yeah, it's not a saying.
SPEAKER_3: Right.
SPEAKER_2: Mine is cancer, I'm a festering malignancy.
SPEAKER_2: Thank you.
SPEAKER_3: Oh man.
SPEAKER_2: All right.
SPEAKER_1: All right.
SPEAKER_2: Enough of that.
SPEAKER_2: Thank you, Jackie, for that.
SPEAKER_2: That was great.
SPEAKER_2: Wow, I got so much out of that, man.
SPEAKER_1: What else you got there?
SPEAKER_2: All right, why don't we, this is Sherman from San Diego says.
SPEAKER_1: Are we still on the Patreon?
SPEAKER_2: This is a Patreon Patreon.
SPEAKER_2: Sherman from San Diego.
SPEAKER_2: Sherman says, hi Dr.
SPEAKER_2: Tyson, hi Dr.
SPEAKER_2: Faherty.
SPEAKER_2: 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.
SPEAKER_2: 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?
SPEAKER_2: So that's a very good question.
SPEAKER_2: Is there anything new and exciting that helps us?
SPEAKER_1: Can I prepend 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?
SPEAKER_3: 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?
SPEAKER_3: 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.
SPEAKER_3: Those objects orbit a star.
SPEAKER_3: And the ones that I study don't orbit a star.
SPEAKER_3: They're in between, yeah, they just, they're off there, they're alone, they have no host star.
SPEAKER_3: So there's nothing.
SPEAKER_3: Yeah, we call them orphan to be nicer maybe.
SPEAKER_3: The orphaned objects that are out there.
SPEAKER_3: 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.
SPEAKER_1: I was talking about that.
SPEAKER_3: It's so much easier.
SPEAKER_1: Is that like seeing a firefly in a Hollywood searchlight?
SPEAKER_1: You can't, the brightness contrast is so high, you can't see the dim things.
SPEAKER_1: So you got objects where there's no main star, so it's just the object itself.
SPEAKER_3: Just it on its own.
SPEAKER_3: But this is where it gets controversial, right?
SPEAKER_3: 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.
SPEAKER_3: 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.
SPEAKER_3: It's probably important for your audience to understand what I'm an expert in.
SPEAKER_1: But just quickly, you're saying that location matters in how you classify such an object.
SPEAKER_3: We don't have a good running definition right now for what it is that we'll call this high mass end problem outside of our own solar system.
SPEAKER_1: High mass planet.
SPEAKER_3: High mass planet.
SPEAKER_3: High mass, so planet or low mass brown dwarf.
SPEAKER_1: So what's a brown dwarf?
SPEAKER_3: 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.
SPEAKER_3: Whatever causes the fragmentation, the compression of the gas, it breaks off into pieces.
SPEAKER_3: The smallest possible pieces that could fragment off.
SPEAKER_1: Wait, so you have the main piece that's the main star.
SPEAKER_3: Well, lots of pieces, right?
SPEAKER_1: But one of them is gonna, the big one's gonna be the star.
SPEAKER_3: There could be hundreds of them that'll be stars.
SPEAKER_1: Oh, of course, all right.
SPEAKER_1: So now you got the other bits and pieces, go on.
SPEAKER_3: Yeah, so there'll be a whole spectrum, a whole distribution of objects that will break off out of a gigantic molecular cloud.
SPEAKER_3: 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.
SPEAKER_3: 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.
SPEAKER_2: But they do it anyway?
SPEAKER_1: They think they're gonna be a star, but they're not.
SPEAKER_3: So, now you guys are putting a motion on it.
SPEAKER_3: They don't know what they should or shouldn't be.
SPEAKER_3: They're just existing.
SPEAKER_3: And so this is why people called them failed stars, because they're not getting enough mass.
SPEAKER_3: But I look at it and like, whatever dude, like who cares?
SPEAKER_3: It is existing with not enough mass.
SPEAKER_3: That's fine.
SPEAKER_3: It doesn't have the mass.
SPEAKER_3: Instead, it can't get that nuclear engine going that's at the center of our sun.
SPEAKER_3: Instead, it's like a coal plucked from a fire.
SPEAKER_3: It just cools through its life.
SPEAKER_3: And that's it.
SPEAKER_3: And that is in between basically what we say is the top mass for that, that it happens, is 75 times the mass of the Jupiter, 75 Jupiters.
SPEAKER_1: That would be a star.
SPEAKER_3: Above that is a star.
SPEAKER_1: That's the quarter, right?
SPEAKER_3: Exactly.
SPEAKER_3: And this is very metalicity dependent, like how much, how much metalicity, how much iron we have.
SPEAKER_2: What's metalist?
SPEAKER_2: Oh, okay, I got you.
SPEAKER_1: Heavy elements.
SPEAKER_2: So at the core, like, okay.
SPEAKER_3: Heavy elements.
SPEAKER_3: So how much of that was available will change like how much mass you need to get the core burning.
SPEAKER_3: But then the lower end of it, the low end, I don't know, what's the lowest mass fragment that you can break off?
SPEAKER_3: This is a huge discussion in astronomy right now.
SPEAKER_3: What is the lowest mass piece that breaks off?
SPEAKER_1: And still becomes a thing.
SPEAKER_3: And it's a thing.
SPEAKER_2: That right.
SPEAKER_2: That thing that doesn't know what it is.
SPEAKER_3: But then, wait, one last thing on it.
SPEAKER_3: One last thing, cause I know we have to stop.
SPEAKER_3: But the planet would be opposite end of this.
SPEAKER_3: Can you form an object, the planets form in a disk around a star, but how big can it get around a star?
SPEAKER_3: So now you've got two competing things.
SPEAKER_3: You've got objects that form by breaking up a cloud that then self fragments and blah, blah, blah, blah.
SPEAKER_3: And then you've got a disk around a forming star and how big can that object get?
SPEAKER_2: Wow.
SPEAKER_3: Planet versus Brown Dwarf.
SPEAKER_2: We gotta take a quick break.
SPEAKER_1: So that's the Brown Dwarf establishment right there.
SPEAKER_2: As opposed to my Brown Dwarf, which was the dwarf that was never painted by Disney because he was racist.
SPEAKER_1: The eighth dwarf, yes.
SPEAKER_1: Chuck has issues, we're getting him through.
SPEAKER_1: When we come back more with Jackie Faraday on the world between planets and stars on StarTalk.
SPEAKER_1: We're back.
SPEAKER_1: Star Talk.
SPEAKER_1: Where are they?
SPEAKER_1: What are they?
SPEAKER_1: We got a word for them, but do we understand them?
SPEAKER_1: And our best chance of understanding them is this woman right here.
SPEAKER_2: Yes.
SPEAKER_1: Jackie Faherty in the house.
SPEAKER_2: Yes, yes.
SPEAKER_1: Friend and colleague in the department of astrophysics right here at the American Museum of Natural History.
SPEAKER_1: And you just described something I hadn't fully appreciated just before the break, that you have this humongous gas cloud, a molecular cloud, they call them, and it'll break into bits.
SPEAKER_1: And these are typically stars, but some might not be stars.
SPEAKER_1: 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.
SPEAKER_1: Did I understand that?
SPEAKER_3: You're doing good, yeah, yeah.
SPEAKER_3: Yeah, I will say, right, so those are the-
SPEAKER_1: So two different kinds of phenomenon going on.
SPEAKER_3: Two different formation mechanisms.
SPEAKER_1: Formation mechanisms, that's the phrase I'm looking for.
SPEAKER_3: Right, and so we want to use that as definitional for saying what kind of object are you looking at.
SPEAKER_3: I'd prefer to know how it formed because can you eject these objects that form around a star?
SPEAKER_1: Yeah, you do.
SPEAKER_3: Oh, 100% you do.
SPEAKER_3: They're launched off, we ejected stuff all sorts of ways.
SPEAKER_1: We might have like 30 planets or something.
SPEAKER_3: Yes, yes, exactly.
SPEAKER_1: And now we're down to eight, get over it.
SPEAKER_1: And so all this would be rogue planets by now.
SPEAKER_3: Rogue worlds.
SPEAKER_1: Or eaten.
SPEAKER_3: Rogue worlds, I like rogue worlds rather than planets.
SPEAKER_2: Or could have any of them become, join forces to become.
SPEAKER_3: Get picked up by another star.
SPEAKER_2: Yeah, get picked up by another star.
SPEAKER_3: Yeah, so we talk about that too.
SPEAKER_3: That's pretty hard to do, but not impossible.
SPEAKER_3: It's possible that it could happen.
SPEAKER_3: They could also, they get scattered around.
SPEAKER_3: And we have evidence for this material now.
SPEAKER_3: 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.
SPEAKER_3: This object called Oumuamua, which is an interstellar asteroid rock that came flying through here.
SPEAKER_3: And that probably got dumped out when its own sun was forming its solar system.
SPEAKER_3: So the one thing on this though.
SPEAKER_3: It is okay.
SPEAKER_2: Don't let the doorknob hit you, Oumuamua.
SPEAKER_1: Oumuamua, by the way, is Hawaiian for scout.
SPEAKER_1: And it's repeated, Oumuamua for emphasis.
SPEAKER_1: So it's basically first scout, if you would.
SPEAKER_3: And it was named that because it was on a, it was found through a telescope in Hawaii, the Pan-Star telescope, which is a wonderful telescope.
SPEAKER_3: And as an homage to Hawaii, they chose this wonderful name.
SPEAKER_1: Yeah, so just, I did this calculation long ago.
SPEAKER_1: This is the perfect time for me to invoke it.
SPEAKER_2: All right.
SPEAKER_1: Because how often does one get to invoke a calculation?
SPEAKER_1: If there were four bumblebees flying in the continental United States, the chance of them accidentally bumping into each other are greater than any two stars in our galaxy.
SPEAKER_1: But if you wanna talk about how empty space is between stars.
SPEAKER_2: That's how much stuff is not there.
SPEAKER_1: It's not there.
SPEAKER_1: So if you have rogue things cast off, there's still the unlikelihood that you would even come into the vicinity of another star.
SPEAKER_1: But even if you did, you can have a velocity that's hard to trap.
SPEAKER_2: Supposed to.
SPEAKER_1: So Oumuamua had hyperbolic velocity, so we're not, it's coming through any, it's not even looking back.
SPEAKER_1: It's coming through every light.
SPEAKER_2: It's gangbusters.
SPEAKER_3: Right, like we didn't capture it, we're not doing anything with it.
SPEAKER_1: We're not doing a damn thing doing it.
SPEAKER_3: It came through like beep, beep, here I come, there I go.
SPEAKER_3: And even looking at its motion, its velocity, it looked like maybe we were its first pass.
SPEAKER_3: Possibly, this is very hard to tease out, but there was a paper on that, whether or not we were the first.
SPEAKER_1: A research paper, yeah.
SPEAKER_3: A research paper that was looking at whether or not we were its first encounter after it departed.
SPEAKER_3: And we traced, astronomers tried to trace it back and see where it might have come from.
SPEAKER_2: Right, so now with that in mind, did we're the first pass, did we alter its course?
SPEAKER_3: Oh, great question, Chuck.
SPEAKER_3: I don't know, maybe, probably a little bit.
SPEAKER_1: Oh yeah, yeah, yeah, it feels, yeah, you can not get captured but still feel what's going on here.
SPEAKER_1: Oh yeah, yeah, so if you look at, they have the trajectory.
SPEAKER_3: Oh yeah, yeah, yeah, yeah, yeah.
SPEAKER_1: And the trajectory is arc.
SPEAKER_3: Right.
SPEAKER_1: In response to the gravity of Jupiter and the sun.
SPEAKER_2: Interesting.
SPEAKER_3: 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.
SPEAKER_3: I'm not sure we can tease it out quite yet cause it still looks like a disc, it's like a disc object.
SPEAKER_3: Just sort of flying around in the disc of the Milky Way.
SPEAKER_1: Beep, beep.
SPEAKER_2: What's that thing?
SPEAKER_2: The Jetsons.
SPEAKER_1: No, the Jetsons.
SPEAKER_2: The flying cars.
SPEAKER_2: Yeah, yeah, yeah, the Jetsons.
SPEAKER_3: Oh, I thought you were doing beep, beep from the right.
SPEAKER_1: It's before your time, sorry.
SPEAKER_3: Ha!
SPEAKER_2: She's like, okay.
SPEAKER_3: Okay.
SPEAKER_1: Yeah, Jetsons were so before everybody's time, you know?
SPEAKER_3: I watched it when I was a kid, so I don't know why it's before.
SPEAKER_1: The Road Runner did a beep, beep too.
SPEAKER_2: Yes, he did.
SPEAKER_1: You know what I just learned recently?
SPEAKER_1: This had nothing to do with anything.
SPEAKER_1: The Road Runner never left the road.
SPEAKER_2: How about when he was standing on air and the coyote would fall?
SPEAKER_1: No, the coyote's standing on air.
SPEAKER_1: The Road Runner isn't.
SPEAKER_2: That's true.
SPEAKER_3: Oh, huh.
SPEAKER_1: Interesting.
SPEAKER_1: Yeah, the road stops before it gets to the edge of the cliff and it's always on the road.
SPEAKER_3: That's interesting.
SPEAKER_1: Hence, the Road Runner.
SPEAKER_3: Yeah.
SPEAKER_3: I have another point on Stellar Flyby.
SPEAKER_3: I wanna just pull it back in here, Neil.
SPEAKER_3: So, you might-
SPEAKER_1: You like my pop culture references?
SPEAKER_3: I do, I love it, I love it, I love it, I love it.
SPEAKER_3: It's so great.
SPEAKER_3: But one of the things that I think is massively interesting right now in astronomy is how many times stars, not run into each other, but interact with one another.
SPEAKER_3: So the issue of, and this is my new thing, I'm really into the new villain of planetary architecture is the stellar flyby.
SPEAKER_3: The unappreciated influence that stars that move by each other can have.
SPEAKER_3: And the reason why I say that is-
SPEAKER_3: Flybys that will change the structure of maybe your planetary system.
SPEAKER_3: Or now like, okay, so the question I think had something to do with what we're understanding about exoplanets and learning about it in the future.
SPEAKER_3: So here's one for everybody.
SPEAKER_3: In one million years, just about one million, it's like 1.1 million years.
SPEAKER_3: I can't give you the exact date.
SPEAKER_1: October 12th, one million years.
SPEAKER_3: Plus or minus like 10,000 years, yes.
SPEAKER_3: 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.
SPEAKER_3: And in one million years, it's gonna pass within our Oort cloud.
SPEAKER_3: It's coming straight in.
SPEAKER_1: So the Oort cloud, the outer region of comets, that's a spherical zone.
SPEAKER_1: Very distant, but very there.
SPEAKER_3: Very there.
SPEAKER_1: Very there.
SPEAKER_3: With lots of material.
SPEAKER_1: Yeah, this is like trillions of comets just waiting to strike.
SPEAKER_2: I was gonna say, that sounds catastrophic.
SPEAKER_3: It's so, we've looked at it.
SPEAKER_3: Astronomers have looked at it to see like, is it gonna be a disaster?
SPEAKER_3: And the conclusion is it's uncertain, but the impact that it'll have on the Oort cloud might not be super bad.
SPEAKER_1: Jan Oort was the Dutch astronomer who first calculated the existence of the Oort cloud.
SPEAKER_1: It's so far away you can't see the objects at that distance.
SPEAKER_1: But when they come in, you see them near the sun and you look at their trajectory.
SPEAKER_1: You say, oh, this much terminate way and out at this distance before it comes back again.
SPEAKER_2: The calls are coming from inside the house.
SPEAKER_3: So if you think about it, the Oort cloud actually stretches a third of the way to the closest star.
SPEAKER_3: A third of the way.
SPEAKER_3: It gets, so I mean, think about that, you know, I mean, you get something that flies between us and that next closest object, it loosens up things.
SPEAKER_1: Because they've only barely held on to begin with.
SPEAKER_1: So any disturbance will completely wreak havoc.
SPEAKER_3: And most important here is the consideration of we're constantly doing mission planning.
SPEAKER_3: Like what are the next stages of mission planning, right?
SPEAKER_1: And what's the name of the star just right now?
SPEAKER_3: So it's Gleason 780, it's one of these names that I constantly mix it with 780 versus 781, I think.
SPEAKER_3: So that's my fear of 780.
SPEAKER_1: Gleason 7, not Gleason, G-L-E-I-S-E, Gleason, Gleason.
SPEAKER_3: G-L-I-E-S-E.
SPEAKER_1: E-S-E, it's a catalog of high moving, fast moving stars, right?
SPEAKER_3: Close, bright, so they're mostly fast moving.
SPEAKER_1: Yeah, yeah, fast moving in their field of view.
SPEAKER_1: So for that to be the case, they have to be nearby.
SPEAKER_1: So.
SPEAKER_2: Man, I was hoping it was Gleason.
SPEAKER_2: It had, no, unfortunately, no.
SPEAKER_1: But just to be clear, it's not.
SPEAKER_1: So this is not a catalog of stars that are actually moving fast.
SPEAKER_1: It's a catalog of stars that are moving fast in our field of view.
SPEAKER_1: So you can have a bird fly by in front of you that's going maybe 20 miles an hour, and a plane that's moving past your field of view much more slowly.
SPEAKER_1: And you're not gonna say.
SPEAKER_2: That the bird is going faster than a plane.
SPEAKER_1: The bird is not going 600 miles an hour.
SPEAKER_1: So that angle matters, and that angle manifests by its distance.
SPEAKER_1: So it's a catalog of selected for their fast movement in our night sky, and those tend to be the nearest objects.
SPEAKER_3: Yeah, right, because we're detecting them.
SPEAKER_3: And so that one had been known, we've known about that star for a really long time.
SPEAKER_3: It's a bright, it's a very bright star.
SPEAKER_3: And it's.
SPEAKER_2: It's headed for us.
SPEAKER_3: We are headed for it.
SPEAKER_3: It's heading for us.
SPEAKER_3: And just think about it.
SPEAKER_3: It's probably got a solar system around it and an Oort Cloud and a Kuiper Belt.
SPEAKER_3: Why not?
SPEAKER_3: Probably the majority of stars, why wouldn't they have them?
SPEAKER_3: And so when you think, I've got all of my, every time I give a science talk, I bring this up.
SPEAKER_3: But don't you want to, we're gonna see it.
SPEAKER_3: Like bring it here.
SPEAKER_1: Wait, wait, that means the Oort Clouds will intersect.
SPEAKER_3: More than that, yes.
SPEAKER_3: The Oort Clouds, the Kuiper Belt's possibly like, whatever this thing's got around it, we could fly something to it.
SPEAKER_3: There's a lot of this discussion about going to Proxima Centauri because we all want to get there like now, where we're all still alive.
SPEAKER_3: At least 780, man, let's go.
SPEAKER_1: That's gonna be even closer when it's close.
SPEAKER_3: It's gonna be so close.
SPEAKER_1: She sound like she's like ready to be there for it.
SPEAKER_2: I was gonna say, and I am so ready to do this one million years from now.
SPEAKER_2: I know, you talking like, you got her telescope all ready for it.
SPEAKER_3: This is very sad because I'll be dead.
SPEAKER_1: You better take them longevity pills before that happens.
SPEAKER_2: No, by then we'll be able to upload your consciousness to a computer.
SPEAKER_3: That'll be so nice, that's good.
SPEAKER_3: I'd like to see it when it happens.
SPEAKER_1: Cool.
SPEAKER_1: Chuck, what else you got?
SPEAKER_2: 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.
SPEAKER_2: This is from Rossy King.
SPEAKER_1: You can do a long one and then I tease the next segment.
SPEAKER_1: Dude, this is how I do this.
SPEAKER_2: Well, you know, if we keep discussing this like this, we'll be able to do it with this short one.
SPEAKER_2: No, this is Rossy King from YouTube.
SPEAKER_2: Actually, I just wanted to ask this for myself too.
SPEAKER_2: Was Jupiter a failed star?
SPEAKER_2: And then the person says, I'm really glad it failed because I love it in the nighttime sky.
SPEAKER_2: How cute is that?
SPEAKER_1: That should be a quick answer.
SPEAKER_2: Yeah, but is Jupiter a failed star?
SPEAKER_2: Which, you know, yeah.
SPEAKER_3: Yeah, yeah, no, it's not no.
SPEAKER_3: The quick answer to that would be no.
SPEAKER_3: But again, let's not call them failed stars.
SPEAKER_3: Let's just call them, well, one.
SPEAKER_1: Achieving planets?
SPEAKER_3: I call them overexcited planets.
SPEAKER_3: Thank you.
SPEAKER_2: Overexcited planets?
SPEAKER_3: I'm not kidding, Neil, this is my coined term.
SPEAKER_1: This is very modern teacher lingo, right?
SPEAKER_3: Overexcited planets, that's what I sometimes call them, but then I don't like planets.
SPEAKER_2: Don't star shame me.
SPEAKER_2: Star shame, don't star shame me.
SPEAKER_3: Love it, you guys are going with it.
SPEAKER_3: I'm not a failed star.
SPEAKER_3: Exactly, Jupiter shouldn't feel in any way, shape or form like it is.
SPEAKER_2: Inadequate.
SPEAKER_3: Exactly, it is a bohemoth of our solar system.
SPEAKER_3: Many times I say if I'm gonna find an Earth-like planet that I'll be comfortable saying, yes, let's consider that habitable, I want a Jupiter at a Jupiter radius away because you know what Jupiter does for us?
SPEAKER_3: It protects us in a lot of ways.
SPEAKER_3: It's the bouncer of the solar system.
SPEAKER_3: 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?
SPEAKER_3: It takes a lot of hits.
SPEAKER_3: Sure, it deflects some of them our way.
SPEAKER_3: Let's not talk about that part.
SPEAKER_3: But unless you want to.
SPEAKER_2: ID, please.
SPEAKER_1: But most of what it does is protect.
SPEAKER_2: It's a protector.
SPEAKER_3: So I'd really like to see if we find an object.
SPEAKER_1: The bouncer of the solar system.
SPEAKER_2: ID, please.
SPEAKER_1: Standing out there.
SPEAKER_2: ID, please.
SPEAKER_3: Right, that's what it says to all the comets as they come in.
SPEAKER_1: ID includes what your trajectory is.
SPEAKER_1: Trajectory, please.
SPEAKER_1: No, that ain't happening.
SPEAKER_1: Keep walking.
SPEAKER_3: So I would not call it a failed chart, call it the bouncer of the solar system.
SPEAKER_3: The most important of the planets for Earth to consider right now.
SPEAKER_1: So how much more mass would it need for it to have ignited a core of energy?
SPEAKER_2: Or not even a core, for it to not have ignited a core of energy and become the overachieving planet?
SPEAKER_3: 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's not a great number.
SPEAKER_3: That was a traditional number that was used.
SPEAKER_1: So about a factor of 10.
SPEAKER_3: Right, and the reason is because at that mass, you can get heavy hydrogen burning, or deuterium burning.
SPEAKER_3: 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.
SPEAKER_3: And so, boom, that was the definition and it's terrible.
SPEAKER_1: 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.
SPEAKER_3: Yeah, it would be a massive thing.
SPEAKER_1: But something about Jupiter, however, that just Jupiter would be proud, I think, is that it is emitting more energy than it is receiving from the sun.
SPEAKER_3: Yes.
SPEAKER_1: So it is a net energy generating object in this solar system.
SPEAKER_2: It's like a blue state.
SPEAKER_2: Sorry, that was very political of me.
SPEAKER_1: I'll fill in those details after this break, when Star Talk continues.
SPEAKER_2: Hey, we'd like to give a Patreon shout-out to the following Patreon patrons.
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SPEAKER_2: Bringing space and science down to earth.
SPEAKER_1: You're listening to StarTalk.
SPEAKER_1: We're back on StarTalk, Cosmic Queries, the worlds between planets and stars.
SPEAKER_1: And we have one of the world's experts on that, Jackie Faherty, one of my colleagues.
SPEAKER_1: She's my colleague, as you all know.
SPEAKER_2: Well, while I'm sitting here, I can be her colleague while I'm here.
SPEAKER_2: Yes, exactly.
SPEAKER_1: No, we get comedians here, they're your colleagues.
SPEAKER_1: If I get one of my people, she's my colleague.
SPEAKER_2: Somehow I lose in this deal.
SPEAKER_1: 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.
SPEAKER_1: So that's still kind of far away.
SPEAKER_1: It's not kissing the door, kissing the boundary there.
SPEAKER_3: No, yeah.
SPEAKER_3: It's in squarely in the we're totally comfortable calling it a planet object.
SPEAKER_3: It'd have to be quite a bit more massive before we start to feel awkward.
SPEAKER_3: There are other systems.
SPEAKER_3: There's one called HR8799, it's the name of the star.
SPEAKER_3: It's the name of the star, and it has.
SPEAKER_1: Again, name for the catalog out of which they come, yeah.
SPEAKER_3: Right, and these stars also have multiple names, but that's the most popular of the names.
SPEAKER_3: I often call that system.
SPEAKER_1: That's the catchiest name.
SPEAKER_2: HR8799?
SPEAKER_1: That's the most popular.
SPEAKER_2: That's the taxi.
SPEAKER_1: That one just rolls off the tongue.
SPEAKER_2: That's like the share of the.
SPEAKER_3: HR8799.
SPEAKER_3: So I sometimes call HR8799 the Brad Pitt of planetary systems that have been directly imaged.
SPEAKER_3: Because if you have a camera, AKA a coronagraph or an adaptive optic system.
SPEAKER_1: Special camera for this, yeah.
SPEAKER_3: Yeah, we point it at HR8799 because it's so pretty.
SPEAKER_2: Nice.
SPEAKER_3: The system.
SPEAKER_3: And you can image four, one, two, three, four planets orbiting.
SPEAKER_1: In one fell swoop.
SPEAKER_3: Yeah, and I would highly recommend for your listeners.
SPEAKER_1: Does Brad Pitt know this?
SPEAKER_3: I have said it so much, I hope so.
SPEAKER_2: Okay.
SPEAKER_3: And that I'd like him to just feel like the honor of the Brad Pitt status of planetary systems.
SPEAKER_3: HR8799, he could just call himself the HR8799 of-
SPEAKER_2: Of Hollywood.
SPEAKER_2: I'm Hollywood's HR8799, baby.
SPEAKER_3: Switch it up.
SPEAKER_1: Just so you know.
SPEAKER_2: Point a camera at me.
SPEAKER_1: So the year I was the sexiest astrophysicist alive.
SPEAKER_1: This is 40 pounds ago, by the way.
SPEAKER_2: I love that we are now measuring chronology in pounds.
SPEAKER_2: That's great.
SPEAKER_1: Brad Pitt was the cover as sexiest man alive.
SPEAKER_2: Cute.
SPEAKER_1: Beyond category.
SPEAKER_1: He had to be in a category in order to take it, but he had no category.
SPEAKER_1: What year is this?
SPEAKER_1: Next time, next question.
SPEAKER_1: Next question.
SPEAKER_2: 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.
SPEAKER_2: As you were talking about these formation mechanisms, what I want to know is, is it possible to have those two formation mechanisms happen simultaneously?
SPEAKER_2: 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.
SPEAKER_2: Can that happen?
SPEAKER_3: So, you're asking a question that basically got asked at a seminar the other day.
SPEAKER_3: I ask it all the time.
SPEAKER_3: And the result would be, is it possible that you can form a brown dwarf?
SPEAKER_3: 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.
SPEAKER_3: And you can make that same kind of object, deuterium burning, through the accretion process or gravitational fragmentation around a star.
SPEAKER_3: And so, can you get, if you're gonna 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.
SPEAKER_3: 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.
SPEAKER_1: On the mechanism.
SPEAKER_1: Yes.
SPEAKER_3: 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.
SPEAKER_1: I take it back.
SPEAKER_3: Pretty good.
SPEAKER_3: Yes, yes, 100%, this is important.
SPEAKER_2: I take it back, Chuck.
SPEAKER_2: Excellent.
SPEAKER_1: So Chuck, this is our final segment.
SPEAKER_1: We gotta go into like lightning round now.
SPEAKER_2: All right, let's move into our lightning round.
SPEAKER_3: Yeah, it was a bell.
SPEAKER_2: Okay.
SPEAKER_1: Go, Chuck.
SPEAKER_2: This is such a fascinating subject.
SPEAKER_1: So Jackie, your answer has to be a sound bite.
SPEAKER_1: We're testing your sound bititude.
SPEAKER_3: Got it.
SPEAKER_1: Okay?
SPEAKER_3: Ready.
SPEAKER_1: All right, go, Chuck.
SPEAKER_2: Okay, this is Kristen Davies, and Kristen says, I'm a seventh grade science teacher in Ohio, and I ask my students for their questions on the topic today.
SPEAKER_2: My students and I enjoy listening to clean episodes of StarTalk.
SPEAKER_2: Okay, now you see why I'm reading this.
SPEAKER_1: Episodes that don't have Chuck in them.
SPEAKER_2: And that's what I'm saying.
SPEAKER_2: Thanks a lot, Kristen.
SPEAKER_2: Yeah, I'm the one reading your question, Kristen.
SPEAKER_2: Just remember that.
SPEAKER_2: During our study times, I listen to other episodes of My Commute to Work, and that gets me pumped up.
SPEAKER_2: So here's what she says.
SPEAKER_2: From the student, how many stars are in the universe?
SPEAKER_2: Has anyone ever counted them, and is it possible?
SPEAKER_2: Another student says, can you turn a planet into a star?
SPEAKER_2: One and two questions.
SPEAKER_1: Okay, first question, go.
SPEAKER_3: All right, so number of stars in the universe.
SPEAKER_2: Universe.
SPEAKER_3: That number's insane.
SPEAKER_3: Number of stars in the galaxy, we're gonna go with 200 billion probably, and so then there's billions and billions of galaxies.
SPEAKER_3: That's why I'm saying too large for me to give the exact number.
SPEAKER_3: Second question, can you turn a planet into a star?
SPEAKER_3: Awesome question.
SPEAKER_3: People are trying to figure this out.
SPEAKER_3: 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.
SPEAKER_1: But we can do a quick, Jackie, we can do the calculation for the number of stars.
SPEAKER_1: If you just say our galaxy has like 100 billion stars, let's say.
SPEAKER_3: 200, let's go with 200 billion.
SPEAKER_1: But it's the factor of two between friends.
SPEAKER_1: So to keep the math simple, 100 billion stars.
SPEAKER_1: And somewhere between 10 and 100 billion galaxies in the observable universe.
SPEAKER_1: So 100 billion times 100 billion, that's 10 to the 21st power.
SPEAKER_2: Okay, there you go.
SPEAKER_3: What do you call that?
SPEAKER_1: That's one sextillion.
SPEAKER_3: Sextillion.
SPEAKER_2: That's a sextillion?
SPEAKER_1: Sextillion.
SPEAKER_2: That seems very small.
SPEAKER_1: Well, let's do it.
SPEAKER_1: So a billion is, stay with me, nine zeros is a billion.
SPEAKER_1: Trillion.
SPEAKER_1: Count the zeros, it's 12.
SPEAKER_1: 12.
SPEAKER_1: Three zeros at a time.
SPEAKER_2: So 12 trillion.
SPEAKER_1: It's a trillion.
SPEAKER_1: 15 quadrillion.
SPEAKER_2: Quadrillion.
SPEAKER_1: 18 quintillion.
SPEAKER_1: 21 sextillion.
SPEAKER_2: Right.
SPEAKER_3: Yeah.
SPEAKER_1: Yeah, so about sextillion stars.
SPEAKER_2: No, but I'm saying, when I say that seems small, I mean, it seems small for the-
SPEAKER_2: Sextillion is small to you?
SPEAKER_1: Yeah.
SPEAKER_3: I mean, it's big.
SPEAKER_3: That's another I don't say, because it's just so big.
SPEAKER_2: I'm talking about when you, from where we're starting.
SPEAKER_2: I think, because you said it's only 100 billion.
SPEAKER_1: In our own galaxy.
SPEAKER_3: In our galaxy.
SPEAKER_2: All right, forget it then.
SPEAKER_1: Plus, if there's not a sextillion stars together, then there's two sextillion.
SPEAKER_2: Right.
SPEAKER_1: At those numbers, these factors are going to-
SPEAKER_1: You want to get the sense of the scale of this more than you would.
SPEAKER_2: But you still can't get the sense of this scale.
SPEAKER_1: And not all galaxies are our size.
SPEAKER_1: No, there's small ones, there's bigger ones.
SPEAKER_3: There's collide galaxies that have merged and come together.
SPEAKER_3: But another thing they asked about counting is that they're actually counting the number of stars.
SPEAKER_3: And there is this survey called the...
SPEAKER_3: It's a European survey.
SPEAKER_3: It's called Gaia.
SPEAKER_3: And counting.
SPEAKER_3: They have...
SPEAKER_3: They're called the Billion Star Survey.
SPEAKER_3: 1.7 billion stars.
SPEAKER_3: And that's huge.
SPEAKER_1: Those are not extrapolated.
SPEAKER_1: They're actually counting.
SPEAKER_2: They've counted a billion stars.
SPEAKER_3: They've measured their distances, how far away they are.
SPEAKER_3: It's the greatest map that humans have ever produced.
SPEAKER_1: 1.7 billion...
SPEAKER_3: Billion.
SPEAKER_1: Objects in a catalog.
SPEAKER_3: That's like a drop the mic moment.
SPEAKER_3: I can't do that here?
SPEAKER_2: I was gonna say, please don't let that hit the ground.
SPEAKER_1: Next.
SPEAKER_2: Keep it moving.
SPEAKER_2: There we go.
SPEAKER_2: All right, this is from Twitter.
SPEAKER_2: And this is Akshat says this, I think that's the name, or whatever, who cares?
SPEAKER_2: How do astronomers study...
SPEAKER_1: Akshat cares.
SPEAKER_2: Akshat probably cares.
SPEAKER_2: How do astronomers study the atmospheres of brown dwarfs?
SPEAKER_2: And how do we even detect them?
SPEAKER_3: Yeah, that's exactly what I do for a living.
SPEAKER_3: And the way that we detect it is directly.
SPEAKER_3: So that's the actual method that we call it.
SPEAKER_1: You can do that for a living.
SPEAKER_3: Yeah.
SPEAKER_2: No.
SPEAKER_2: That's a great thing to say.
SPEAKER_1: A moment.
SPEAKER_1: Just a moment.
SPEAKER_2: Let's all hold hands.
SPEAKER_1: Meditative moments.
SPEAKER_2: It's a wonderful thing that you can do that for a living.
SPEAKER_1: Okay, go.
SPEAKER_3: Yeah.
SPEAKER_3: I also say the tagline for astronomers, though, is unlocking the secrets of the universe for a living.
SPEAKER_3: That's a good tagline, right?
SPEAKER_3: I mean, sure, studying the atmospheres of Brown Dwarf sounds good, too, but unlocking the secrets of the universe.
SPEAKER_1: Remember, we're in lightning round.
SPEAKER_1: I know.
SPEAKER_3: Sorry.
SPEAKER_3: Direct imaging is the technique that we use.
SPEAKER_3: Then I basically take a telescope.
SPEAKER_3: I point it directly at the object.
SPEAKER_3: For the most part, I have to use infrared instruments, though.
SPEAKER_3: 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.
SPEAKER_3: And I'll take it and I'll take the light.
SPEAKER_3: I pass it through a spectrograph and I look at what it's made.
SPEAKER_3: What is the chemical composition?
SPEAKER_3: What kinds of lines do I see?
SPEAKER_3: And mostly it's molecular features.
SPEAKER_1: Cool.
SPEAKER_1: All right.
SPEAKER_2: Excellent.
SPEAKER_2: Let's move.
SPEAKER_2: There we go.
SPEAKER_2: This is Tom Cat.
SPEAKER_2: Thank you, Tom.
SPEAKER_2: Tom Cat wants to know this.
SPEAKER_2: Do brown dwarfs have surfaces or are they just balls of hot gas?
SPEAKER_3: Yeah.
SPEAKER_3: That is, we're often asked this and there's no surface for you to stand on, similar with Jupiter and Saturn.
SPEAKER_3: You're not going there and standing and having a really nice time.
SPEAKER_3: Yeah.
SPEAKER_3: No, we study-
SPEAKER_2: That's why I call them gas giants.
SPEAKER_3: Yeah, gas giants.
SPEAKER_3: And so brown dwarfs are souped up gas giants.
SPEAKER_2: Okay.
SPEAKER_3: They're very similar to Jupiter.
SPEAKER_1: So there's no point deep enough where it's dense enough that you can call it a surface?
SPEAKER_3: There might be.
SPEAKER_3: We don't know.
SPEAKER_1: You don't want to test it.
SPEAKER_3: You'll die.
SPEAKER_3: We all die, right?
SPEAKER_3: But-
SPEAKER_3: Could they have some sort of core similar to Jupiter or Saturn, which would have some sort of core?
SPEAKER_3: Very well it could have that.
SPEAKER_3: We don't know yet, though.
SPEAKER_2: Excellent.
SPEAKER_2: This is, ooh, Luigi Vanni.
SPEAKER_2: Luigi Vanni says this.
SPEAKER_2: 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?
SPEAKER_3: So that sounds like they're asking about the transit method.
SPEAKER_3: 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.
SPEAKER_3: And 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.
SPEAKER_3: You have to have the timing down like smack down to when that transit is happening.
SPEAKER_3: You look right at the star and you can see what it's made of.
SPEAKER_3: This is very complicated.
SPEAKER_1: We see what the atmosphere of the planet, the transiting planet is made of.
SPEAKER_3: Right.
SPEAKER_3: Through the light of the host star.
SPEAKER_3: It's a very complicated method.
SPEAKER_3: My preference, just to re-engage us back to brown dwarfs, is we draw upon what we do in brown dwarf science.
SPEAKER_3: Since we directly detect the atmospheres, we can guide any measurements that you want to make when you're trying to make detections of objects.
SPEAKER_1: You have ground truth of what the atmosphere might be for those who are looking for the transit in front of a much brighter star in the background.
SPEAKER_3: We are ground truth for transiting planets, especially hot Jupiters, these objects that are pretty close in that are like Jupiter.
SPEAKER_2: Cool.
SPEAKER_2: All right.
SPEAKER_2: Here we go.
SPEAKER_1: Actually, I think we just ran out of time.
SPEAKER_2: Did we really?
SPEAKER_1: We ran out of time.
SPEAKER_2: All right.
SPEAKER_2: That's sad.
SPEAKER_1: You know what I think we should have?
SPEAKER_1: We should have put a few of those online and have Jackie answer them.
SPEAKER_2: Oh, that's a good idea.
SPEAKER_1: Yeah.
SPEAKER_1: I'll put in for that.
SPEAKER_2: It's amazing.
SPEAKER_2: People really are excited about brown dwarfs, man.
SPEAKER_1: Into what you get paid for.
SPEAKER_2: They really are.
SPEAKER_2: All right, Jackie.
SPEAKER_1: Thanks for being on StarToys.
SPEAKER_1: It's not your first rodeo with us.
SPEAKER_1: No.
SPEAKER_1: Thanks for being on.
SPEAKER_3: Well, I've done All Stars with Chuck, but this is the first time we've ever done one.
SPEAKER_2: Is it our first time?
SPEAKER_2: It is our first time.
SPEAKER_3: It is our first time.
SPEAKER_1: Yeah.
SPEAKER_1: Oh, so you go way back.
SPEAKER_1: Yeah.
SPEAKER_2: 89.
SPEAKER_3: I'm an HR.
SPEAKER_2: 89.
SPEAKER_3: 89.
SPEAKER_2: Of co-hosts.
SPEAKER_1: This episode of StarTalk to a close, I thank my co-host Chuck Nice, my friend and colleague Jackie Faherty.
SPEAKER_1: Thanks for coming on, and as always, I bid you good-bye.