 live now. Okay. And we'll get started here in about a minute. On Hercules Starkators. Yay. Hi folks. So I see a lot of the messages that are going to host and panelists and not to everyone. And so the only people that can see your greetings when you do that are those of us here. Well, let's get started. So hello everyone and welcome to the October NASA Night Sky Network member webinar. We're hosting tonight's webinar from the Astronomical Society of the Pacific in San Francisco, California. Two of us are actually in the office. I am not, but I'm still in San Francisco. And the rest of us as noted, Dave is in Potsdam, New York as usual. And Jackie Faraday is in Baltimore. And we're very excited to have her join us this evening. And she's actually from the American Museum of Natural History in New York City. Welcome to everyone on the YouTube live stream. We're very happy to have you with us. These webinars are monthly events for members of the Night Sky Network. For more information about the Night Sky Network and the Astronomical Society of the Pacific, check the links in the chat that I'll put in in just a moment. But here's Dave with just a couple of announcements. Alrighty. Hi, folks. It's good to see you all tonight. I just have a couple brief announcements as Brian just said. All right. First thing, that's actually really the only thing. Just in case you missed it, pins are now available. I'll post the link in the chat in a second. And the announcement is in this month's newsletter as well. And it'll be in subsequent ones. I'm going to repeat it the next few months. We'll send out more reminders, so don't worry. Especially because the deadline for ordering is March of next year. Plenty of time. Just in case you've already ordered pins and have not received them, that's because we're having an issue with our shipping software because of the lovely, lovely nature of software updates. Hopefully we'll get that resolved real soon and get those pins out to you folks. And of course, as always, remember to add reports to your events that have been posted to the NSN calendar so you can qualify to order these pins. And that is all I have for now. Back to you, Brian. All right. Thanks, Dave. I also want to remind everyone that we are still accepting applications for the Eclipse Ambassadors program. We are starting up the pilot workshop this week, but we will have a full slate of workshops and training starting in 2023. And so I think Vivian, if I can get her to put the link in the chat. And we'd love to be able to see all of you apply. For those of you on Zoom, you can find the chat window and the Q&A window at the bottom edge of the Zoom window on your desktop. Please feel free to greet each other in the chat window or to let us know if you have any technical difficulties. Also, make sure that you go down there and select everyone and because it defaults to just host and panelists. You can also send us an email at night sky info at astrosociety.org. If you have a question you'd like Jackie to answer this evening, please type it into the Q&A window that really helps us keep track of things and know whether or not we've answered your question or not. So please refrain from putting your questions in the chat. Please put them in the Q&A. And I'm going to hit you. I want to say I welcome again to the October webinar of the NASA Night Sky Network. This month we welcome Dr. Jackie Faraday to our webinar. And I'd like to introduce our own Teresa Summer, who will introduce Jackie. So, Teresa. Thanks, Brian. Jackie Faraday is a senior scientist and senior education manager at the American Museum of Natural History, or AMNH. And she got her PhD from Stony Brook University, which is where in New York, which is where I'm from and where Jackie currently is. Well, not right now, but in general. She also did postdoctoral work at the Universidad de Chile in a National Science Foundation grant fellowship, and then also with the Carnegie Institute for Science on a NASA Hubble Fellowship. She currently co-runs the Brown Dwarf in New York City research group. And that is really at the forefront of low mass stars, brown dwarfs, giant exoplanets, all characterizing all of those types of planet-like objects. And you'll hear a lot more about that in a minute. Also, I want to tell you she did a citizen science project called Backyard Worlds Planet Nine, which has had more than 150,000 volunteers looking for cold planets, planet-like objects in the nearby solar systems. And in addition to being an amazing educator and scientist, Dr. Faraday has been working hard to create more opportunities for underrepresented minorities entering STEM. And so I'd love to turn it over to you, Dr. Faraday. Thank you, Teresa. Hello, everybody. I'm very happy to be here with you to let you know where I am physically right now. I am in Baltimore, Maryland. And I'm here because I'm here for a three-day meeting at the Space Telescope Science Institute. And tomorrow I'm giving the colloquium that is a joint colloquium between the Space Telescope Science Institute and Johns Hopkins University. And I'm telling you all that in part because the talk that I'm going to give you tonight is going to be a bit of a practice talk for the talk tomorrow. So you might see some high-level slides. I'm going to try and talk you through everything the way I would. I'm not assuming everybody in here is a PhD astronomer working for Space Telescope or Johns Hopkins. However, I know this is a very well-informed group. So bear with some of the plots. If you're wondering why I'm showing you some things that seem a little bit confusing, ask about them in the chat if you want to. Otherwise, I'm going to give you more broader information, which hopefully just listed in my words. All right. So I feel like we'll get started. Right, Teresa? I can start sharing screen. Should be good. Yes. Go for it. Okay. Everybody might disappear from me. Let's hope not. All right. We're good. Everybody can see this? Yes. Yes. All right. Here we go. So I'm going to make sure my timer is on. Great. So today's talk is on the importance of brown dwarfs. This is a little video that I rendered of a nearby flight that you might take. He or say, I don't know, 30 light years away and highlighted in purple with the constellation lines that you might know from your nighttime sky, all connecting lines around are the positions in three dimensions of these objects called brown dwarfs. Important for you to know is that brown dwarfs are everywhere, but I guarantee you, not just guarantee you, I know you have never laid eyes with your eyeballs on a brown dwarf because they're too faint for you to see. What they are are objects that exist in mass space in between stars and planets. So we can all go outside, look up and know that there's the sun there. We're familiar with that, and this image on the left is an image from Soho of the sun. And then I think most people have an idea of what a planet is, or at least you've got an idea in your head of what a planet is. Jupiter is not really a debated one. Pluto is a debated one. Jupiter, nobody debates. Jupiter is a good planet to give us an example. And Jupiter is actually going to be a mass designator for me for the rest of the talk, as brown dwarf masses are often given in terms of Jupiter masses. And that is because brown dwarfs exist in mass space in between stars and planets. At 75 times the mass of Jupiter, 75 times the mass of Jupiter is when the class of objects called brown dwarfs begins. Why does it begin at 75 times the mass of Jupiter? The reason is that at that mass, you can't push the core of an object tight enough together to get the core hot enough to get nuclear burning going. Instead, what happens is that at 70 times the mass of Jupiter, electron degeneracy pressure kicks in, or basically the electrons are kind of like people on the New York City subway. If too many people sit next to each other in a row, you get a little bit of a push back, not interested in that. And so rather than being able to contract further and further and further to get a core hotter and hotter and hotter, electrons prevent that and an object just kind of maintains a temperature whereby nuclear burning cannot occur. So you can't get a nuclear engine at the core of a brown dwarf. That's the core of the definition of a brown dwarf. The low mass end of brown dwarfs is much harder to identify. The boundary between what we would call a planet and what we would call a brown dwarf is super gray. At 13 times the mass of Jupiter, you stop getting even what's called heavy hydrogen burning. You get nothing. The object just cools. And that's sometimes used as a definition of a planet, but it's just like a bad definition. So please don't walk away from this thinking, oh, I think I understand what the upper boundary of planets is. The word planet is a very, very, very tricky word. It doesn't really come with a lot of ease from a scientific classification sense. So brown dwarfs are objects that exist between planets and stars, and they truly bridge stars and planets. Thinking about them a little bit more deeply, you might remember that stars come in flavors of spectral classes. Our sun, for instance, is a G-type star, which means that its effective temperature or the temperature on its outer photosphere is about 5000 degrees Kelvin or so. Brown dwarfs start around 3000 degrees Kelvin at their hottest. And at their coolest, they're about 250 degrees Kelvin, which is kind of like a cold day on the North Pole. And they come in these four classifications, M types, L types, P types, and Y types. And each one of those types tell you something about the temperature of the object. So keep that in mind. MLTY is the extension of what you might know of the OBA FGK. Those are the spectral types for stars. And then the M's come LTY. Another important factor for brown dwarfs is that because these objects lack stable hydrogen fusion at their core, they have what's called a degeneracy, whereby you could say to me, oh, I'm looking at a T dwarf, it's probably a 50 Jupiter mass object. You can't do that. It's degenerate. They don't have a main sequence the way that stars have a main sequence. So unfortunately, they hide their age. I wish I could hide my age. I wish I could hide my mass or and my age as well as brown dwarfs do. Without knowing the age, you can't find out the mass. If you have the mass, you might be able to back back out the age. But they're degenerate from each other. You need one to get to the other. All right. These are all important parameters about brown dwarfs that I'm going to intro you into. And I'm going to take you through three different stories of brown dwarfs that are important. And we're going to land on the James Webb Space Telescope at the end of this. So this little figure is a montage of brown dwarfs of objects that I can show you. You could never see these with your eyeball. They're way, way, way too faint for your eyeball. But you can see them if you have a telescope in space like the Widefield Infrared Survey Explorer that NASA launched and studied this guy with for many years. It's actually still in space doing science. These are all little rendered videos that are showing you a five to seven year time baseline between the first image that blinks and the second. And that dancing orange dot that you're seeing is an isolated cold compact object or an isolated brown dwarf. The majority of brown dwarfs are found alone. They are found all by their lonesomes. They are not found around a star for the most part. They're found wandering around space, similar to how you find a lot of stars just wandering by themselves. But as a result, these objects are far easier to study than planets are. Because planets, you have to block the light of a bright star in order to try and access the planet itself. The majority of planets that have been discovered have been discovered indirectly by what they do want to do is study the light directly from the object. This whole suite of objects that I'm showing you here are the coldest of the brown dwarf classes and the ones that resemble in so many ways Jupiter. So I'm showing you a suite of super Jupiters, all of which were discovered by citizen scientists that work with me in a project called Backyard Worlds colon Planet Nine, which I invite all of you to participate in if you're interested in. Go to backyardworlds.org. It's a Zooniverse citizen science project. Now isolated brown dwarfs are the majority. However, however, and this is where it's going to get interesting, sometimes you do find the brown dwarf orbiting something. And now in this montage of videos, there is sometimes a little orange dot. Sometimes it's just like a it's it's a bit of a warmer brown dwarf. So it's going to look more black. And in each one of these cases, you get this big bright star bouncing back and forth and find yourself that other dot that's also bouncing back and forth with it. And these are what are called benchmark brown dwarf companions. We call them benchmarks because like I said at the beginning, brown dwarfs are degenerate. It's super annoying. You can't figure out their mass, their age. They hide all sorts of information because they don't have hydrogen burning at their core. But if you find it orbiting a main sequence star, which is the case for each one of these, a main sequence star is the host. Then you can use the information that you have about the host star. It's metallicity, it's age, it's pair, it's distance. If you can't, if you don't actually have the brown dwarf systems, you get all that information and you can apply it to the brown dwarf and then you learn all sorts of stuff. So that's really important. These are called benchmark brown dwarfs. Now, extra bit of info. I'm going to show you a plot. It's a very famous plot next. The very famous plot in exoplanet science. It's a very famous plot in brown dwarf science. I'm going to talk you through it. And it's going to showcase for you where you find some of these benchmark systems where you've got a brown dwarf orbiting a star. So here's the plot. On the x-axis, you've got the separation of a system or the semi-major axis in astronomical units. So follow the x-axis on the far left. You're seeing things that are super, super, super close to their parent, their parent star. And on the far right, you're seeing things that are super, super far away from their parent star. And I've given you a couple of mile markers like where the earth is, where Saturn is, where Pluto is, where the orc cloud is, which is oftentimes considered the end of our solar system. And then on the y-axis, I'm showing you the mass ratio of a system, what the mass of the secondary is, the planet, the brown dwarf, divided by the mass of the primary. So on the bottom left hand is going to be systems where you have a t-cap object in comparison to the primary. So like earth orbiting the sun. And then on the top of the top left hand corner are objects that have the same mass. So a star orbiting a star, a brown dwarf orbiting a brown dwarf, a planet orbiting a planet, whatever the case, the mass of the secondary is the same as the mass of the primary. It's a near-equal mass system. And you might notice that this plot has very specific areas that get occupied, and kind of an area that's not occupied. And many times, this figure is used to argue for formation differences in populations of objects. So on the bottom left hand side, you have exoplanets, objects that we would call an exoplanet because clearly they formed around the star. On the top right hand corner, you have binaries, a star that's orbiting another star. But in between, there's this gray area. There's clearly stuff, there's not a ton of stuff, but that's a transition area. And in it are a number of brown dwarf companions. And you might say, oh, cool, this looks kind of like science is in here, right? Like there's a lot of science in here. But what's the science? I mean, the science is the formation pathway of how the system came to be. So on the bottom left hand side, they probably formed in a disk around a newly formed star. And in the top right hand side, they formed through a giant molecular cloud that just fragments like shattered glass, and you get two pieces. In between, I don't know, maybe it's some secondary formation, some mix, maybe it's a fragmentation in a disk, maybe it's a big disk fragmenting, maybe it's another formation mechanism, maybe it's the fallout from whatever happens in the binary process from stars, and the fallout from something that happens in the exoplanet process around a disk. One way to test it is if you could access the chemistry, the bulk compositional chemistry of the objects in the transition area, or really all of the objects on this plot. So part one of this talk is going to tell you how we figure out the chemistry of brown dwarfs. Can we assess the bulk chemistry of them? And can the bulk chemistry differentiate a formation mechanism for them? I'm going to give you the first case example of this. I'm going to take you through one really clear example. Back to this plot, I'm going to dive deep into an object, into a system that's up here. It's not quite the transition area, but it's closing in on it. So we're going to go with it because we did a pretty deep study on this object. It's called GLISA 229B. Here's the study. This was led by my graduate student Emily Calamari, who's pictured in the upper left. This is what data looks like on a brown dwarf. If you were to take the light of the brown dwarf and you pass it through a prism, you see the following. On the bottom, on the x-axis, it's telling you the wavelength that you're looking at. And on the y-axis, it's telling you how much flux is coming out. So at 0.5 microns, that's optical. You can see that light. And then as you move farther and farther to the right, that's redder and redder and redder, and you can't see that light. That's near-infrared all the way to the right-hand side where we consider it mid-infrared light that's coming out of these things. You can see that the light from this brown dwarf is dominated by methane gas. You get a lot of methane gas in Jupiter, too. There's water absorption. You get carbon monoxide, CO, CO, CH4, and H2O. And what we want to be able to do is we can see that these absorption features exist in this spectrum. But what we actually want to do is figure out, like, how much carbon is actually there? How much oxygen is there? Because the holy grail of brown dwarf science, of formation science, is to figure out what the carbon to oxygen ratio is in the chemistry platform of an object in order to figure out what a formation pathway might look like. If it's solar, if it looks like what the sun has as its chemical composition, then it probably just formed the way stars do. If it's enhanced much larger than solar, it probably formed the way that binary stars do. Okay, so in order to do this, I have to use a pretty complicated technique. We call this technique the spectral inversion technique or the retrievals technique. My very close colleague, Ben Burningham, has written a code. It's called Brewster. That is not an acronym. It doesn't stand for anything. It's named after his dog. And it's soon to be open source. So even anybody on the call could play with it if you wanted to. And my former graduate student, Eileen Gonzalez, pictured there has done a lot of work using this code. These two papers that I highlight up here talk all about the code. So if you guys are interested in looking at articles online that are astrophysical peer reviewed articles, you can go to the monthly notices of the Royal Astronomical Society and look for these papers. And you can read all about the technical aspects of the code. We're going to use this code, which is going to give us the chemistry of the objects. Here's the data again. That light passed through a prism, seeing what it's made of. You can see the water, the methane, the CO. And in black is the actual data that we got from the telescopes. Overlaid in green is the best fit that we got out of a model. And the thing I want you to take away when you look at this is that it looks like it fits. So we used this code to do a fit to the data. And in order to do that fit, we took all we knew about the chemistry that might be in the object. And we had some guesses at what may be the current distribution of gases and what not. And we initiated the code and we said go. Figure out what the best model is for this object. Because we want to know what the carbon to oxygen ratio is. And if we're going to figure that out, you need to tell me what the actual abundance is of these molecules that you're seeing there. So we got some answers. We tested a suite of models and we found the following. This is a cloudless object from our perspective. Jupiter is very cloudy and I was describing these things to you in context with Jupiter. In this case, we're not looking at the clouds. We are not seeing clouds. We're really looking at a lot of methane. And we were able to properly constrain gases in this system. Water, carbon monoxide, methane, ammonia, and then sodium and potassium. All of that we can see in abundance in this object. Now remember I said this is a benchmark system. Benchmark means that it is co-moving with a main sequence star that we can test to see how well it fits with the host star. So I've created this table for you that shows you four parameters. In the first column, it's going to be what we got for the host, for the primary. And the second column is telling you what we retrieved with this code. And the first row is showing you how much carbon we found. The second is how much oxygen. And the third is the carbon to oxygen ratio. Let's focus on that for a second. Because something's up. The primary in this system, the main sequence star, has a 0.68 value for its carbon to oxygen ratio. And spoiler alert, that's pretty close to solar. That's kind of what the sun has. But our companion comes way enhanced with a carbon to oxygen ratio that's almost twice what the primary is. If you were to take that at face value, you would assume that means it formed in a disk around this star. But I can tell you right now, there's no way that's the case for this system. Something else must be up. Let's look at this compared to other systems for which we were able to try this technique. So now this is a plot of other very famous companion round dwarf systems that are moving with a host star. And it's showing you how far separated they are on the x axis. So on the far left, it's like really close to the host star. And on the far right, it's really far from the host star. And then on the y axis, it's showing you what the measured carbon to oxygen ratio is. The dashed line shows you the solar value, what the sun would look like. And we really expect things should all be landing at solar unless something happened. And you can see this object has a very clear difference from its host star, at least a 229B compared to A. But it's not the only one. If you look at that purple box, HD3651B, it's also got a pretty significant differential between its host star. Other things match pretty well and maybe even match solar. So clearly something's up here. So we checked one other thing on this, and that's how well this brown dwarf might mesh with what other isolated objects look like. And this is a big plot. Now on the x axis is the temperature of the object versus the C to O ratio. And while you're going to, if you stick around astronomy long enough, you will hear C to O ratio, C to O ratio, C to O ratio over and over and over again. Because it is a, like I say, a holy grail for trying to figure out where something might have formed. But clearly, we don't really have a good understanding of how to do this for brown dwarfs. Lisa 229B, which is the one that my student Emily Calamari is publishing right now looked super solar. It had a big differential from its primary. But look at all those other brown dwarfs that are also coming up with a super solar C to O ratio. This might make you think that all of these things formed in a disk, but the majority of them, all of the blue dots here are isolated. No host star. So what disk did they form it? Something's different. What might it be? Well, I think it could be unaccounted for clouds. And why do I say that? Because the clouds create an oxygen sequestering, which will drive a higher C to O ratio. So if you don't account properly for the clouds, and we tried, we just didn't see them in the data, then you're going to get a particularly high C to O ratio. So this could be telling you that brown dwarfs are cloudier than you think. And we know they're cloudy. So now let's talk about clouds. This is a little visual rendering of what maybe some of these brown dwarfs look like. And the question that I'm going to pose to talk to you guys about is, is there enough information in the observed properties that we have of brown dwarfs to confirm the presence of clouds and to determine if the cloud composition and the weather patterns, what they look like, what do they look like? And I take a step back from complicated science plots and describe to you what those clouds might look like. This is a picture from where I work at the American Museum of Natural History and the newly renovated Hall of Gems and Minerals. It's beautiful. I invite everybody to come visit us. And in that hall, you see these cases, these cases, whole cases of gems and minerals found across this planet. This one is a case of silicon dioxide or quartz and all of the beautiful forms that quartz comes in, rocks, as we would think of them, or rare gems and minerals. For brown dwarfs, this is what's in the clouds. These are the clouds in brown dwarfs. Here's another case of inocilicates. Ancetite, forsterite, all sorts of interesting silicate. They look like rocks, gorgeous rocks, but these are the kinds of condensates, cloud structures that you're going to get on these objects. Now, how do I know that? Here's the observational evidence. Here's a look at a compilation of colors of brown dwarfs. On the x-axis, I'm showing you the type of brown dwarf from the warmest ones on the left-hand side to the coolest ones on the right. And on the y-axis, I'm showing you how red the object is. And you can see as the objects go from the hot m dwarfs to the cooler l dwarfs, they get redder and redder and redder. What's happening there towards the top of the triangle is the objects are getting more and more of those silicate clouds. This is our prediction. And then very quickly, the chemistry changes and you lose those clouds as they get bluer and bluer and bluer and the triangle comes back down and you get to an object like Lisa 229b that I just showed you that doesn't show us any clear indication of clouds. It doesn't mean no clouds. It means the clouds might be super deep. Whatever the case, those clouds have dissipated from our ability to observe them, the current data that we have. And then we can actually look at the spectra. I showed you the Lisa 229b spectra. Here's a little array of other spectra. You take the light of the brown dwarf, you pass it through a prism, you see what it's made out of. And warmer brown dwarfs, they got a lot of hydrides and oxides, titanium oxide, iron hydride. They got some CO. You get to the coolest ones and you got a lot of methane. I want to zoom in in an area. It's going to be very relevant for us. And this is an area where you're going to find signatures of silicate of those beautiful minerals that I just showcased you are at the Hall of Gems and Minerals at the museum. Let's zoom in. Have a look. This is a zoomed-in portion of one of those warmer brown dwarfs. And if you notice the spectrum bends a little and then elbows over, that is absorption from silicates. I didn't tell you what kind of silicates. I didn't tell you which rock in the case in the Hall of Gems and Minerals because I'm not totally sure. But I can bounce between these two spectra. Zoom back in. This object has it. This object does not. This object has it. This object does not. That means that that silicate feature varies across temperature for brown dwarfs for sure. So cloud properties must vary across these objects. A postdoc in my research group named Genaro Suarez has recently done a really amazing study looking at how that silicate feature varies across brown dwarfs. Now this plot, similar to the color plot I was showing you a second ago, is showing how you can measure this feature in the spectrum, that bending in the spectrum, and then look at how it changes with temperature or with spectral type, which is on the x-axis here. And you see it gets bigger through the eldwarfs deeper, get a lot more of that silicate, and then it just drops off for the teedwarfs. It doesn't fully disappear, which is a notable thing. So the clouds have seriously dissipated, as was indicated in that first object I told you we came up with cloudless on, but it's not totally gone. Now I'm going to dig into two objects just to demonstrate to you how cool this is. Two objects that had that signature of silicates. They're famous brown dwarfs, and this is going to be work I'll describe for you that's led by a postdoc on my team, Johanna Voss. One of the brown dwarfs is called Simpa136. The other is called TwoMass2139. We recently discovered that these two brown dwarfs, both of which vary a lot in their light, indicating that they have some sort of storm happening on them. We recently realized that both of these systems are in a moving group, kind of like a cluster, but it's heavily dissipated cluster. Some of you might know open clusters like the Pleiades or the Hyades. Those are pretty dense clusters, still pretty gravitationally bound to each other. Moving groups have dissipated, and the sun is actually moving through a couple of these moving groups. One moving group that's pretty dispersed across the sky is called Carina Near, and it's about 200 million years old. Both of these brown dwarfs are in it. Now, remember I told you that brown dwarfs do a really good job of hiding their age, their mass, but if you can figure out one, you can break the degeneracy and figure out what the other thing is. In this case, we figured out the age by noticing that both of these brown dwarfs moved with the Carina Near moving group, and that meant we could figure out their masses. So both of these objects are between 10 and 20 Jupiter masses, which makes them a category of objects that we call super Jupiters. Now we studied both of these objects in detail to try and figure out what was happening with their clouds, and we found something spectacular about both of them, independently studying both of them. Here's a look at one of them. This is SIMP0136. We've taken the light, we passed it through a prism, we looked at what it was composed of, we saw a lot of methane, we saw the water absorption, we saw CO, and we saw the silicate feature. Yay, means clouds for sure, and this is a T type object, so clouds. In black here is the data. In green is our model, how we modeled the data. I'm going to show you the same thing for that other object, what I'm going to call its twin. We had less data on this object, but even still enough to come up with a really good model of what might be happening in the object. So black is the spectrum, pass the light through a prism, break it up, see what it's composed of, methane, water, CO, and then that silicate feature. And the green is our overlaid model on top of it. In the case of both objects, independently studied, we came up with the exact same conclusion. They're cloudy, surprise, surprise. They're patchy clouds and they're patchy specifically a form of a silicate cloud called forsterite, a patchy forsterite cloud over an iron deck cloud. That was our best fit model after we threw a kitchen sink of models trying to solve what kind of clouds would drive the objects to look the way that they did. And both objects came up with the same solution independently. We constrained a whole bunch of gases and we even located where the clouds were. I'm just going to quickly skip through this plot. We've figured out where exactly the clouds were. We saw how the profile, the temperature, and the pressure change for these objects. I'm just going to go to the results because I think that one's maybe a little too in-depth. And here's the same chemistry that we got out. I showed you this for Gliese 229B. I'm going to show you this for this system. Simpo 136, two mass 2139, twin brown dwarfs. We were able to find that Simpo 136 likely had 70% cloud coverage by that forsterite cloud. And two mass 2139 was more like 83%. But that's pretty darn similar. And there's C to O ratios. The holy grail value was almost solar. Okay. So this one we clearly figured it out. But we also figured out the clouds in this one. So maybe that's why we got it so close to the value. But there are differences between these two objects. Their water abundances and their CO abundances were different from each other. That meant that the metallicity or really the hydrogen was different between them. So while lots was similar between them, same cloud composition, similar gases, for the most part, these two differences with the hydrogen had us scratching our heads. But here's a cool thing about these two systems. Simpo 136 is an aurora emitter. We have detected aurora emission from that object. And so we postulate one possible explanation for the differences and what basically comes down to hydrogen issues for this object is because of some chemical dissociation process driven by this aurora that's happening on Simpo 136 that doesn't appear to be happening on two mass 2139. So awesome physics, basically, is what we're able to say studying these objects. Okay. Let's skip this to this next important phase here. And that is we were able to look at these objects as they were rotating around and around. We were able to back out what's called a light curve for them. You see an object spinning and you watch the light change. And as it's kind of up and down and brighter and fainter, what we back out is a weather like pattern that's happening on this. Now, Simpo 136 and 2139, both of them showed really nice variability structure. And I recently had a Spitzer space telescope, large program, 600 hours with this space based telescope, to discover that young objects were far more likely to show variability. So that's something you have to take into consideration. Cloudy brown dwarfs, sorry, young brown dwarfs are far more likely to be cloudy than older brown dwarfs are. Young dwarfs out here. The other thing, the angle that you see objects at probably impacts your ability to characterize the cloud. For instance, if you're looking at it pull on, as I'm showing you an image of Jupiter pull on versus equator on, it's probably going to make a pretty big difference in how you look at the object. And this is this amazing plot that we made last week in my office, my current postdoc, Gennaro Suarez, worked with me on this. On the x axis, it's the strength of that silicate index, like how strong of an absorption of silicate that you're getting in the spectrum of the object versus the y axis, which is showing you the inclination angle of a source. Pull on is at the bottom, equator on is at the top. I'll fill it in. And you can see brown dwarfs clearly show a correlation between inclination angle silicate index. Aka, if you look at the thing equator on, you're going to measure much stronger signatures of clouds than if you were to look at it pull on. And you don't get to decide, nature decides, if you're looking at something pull on or equator on, you can't like change your vantage point. Alright, JWST. The big thing in the room, JWST is giving us data. How are the brown dwarfs going to help us solve JWST data? Well, there was recently an amazing result that showed up all over the press. And it was on this object VHS 1256B, a cloudy object very much like a brown dwarf, but just very low mass. This is the gorgeous JWST spectrum on the bottom that shows you the near infrared out to the mid infrared. And I can zoom in for you on that silicate feature that we've been focusing on. You see that bend the elbow and the bend and the dip indicating to you that you've got silicates in there. And we're going to retrieve this object. We haven't figured out how to do it yet, but my postdoc, Nile Whiteford is about to do it, a retrieval of this object. This is a cloudy brown dwarf for sure. More to come on this, but I wanted to showcase for you guys how this is higher resolution than we just had. There's a lot more to solve. We're getting a lot more data from JWST. One thing about VHS 1256B, though, is that this object, are we almost ready, Teresa? That this object is actually sitting in a place on this figure I showed you at the beginning of the talk that has, it's kind of in like no man's land with the stellar binaries. So I don't expect the chemistry to be too crazy on that object. All right, last part of this, because I want to show you some brand new, no one has seen it yet, JWST data. And that is to give you some diversity clues. How are we going to figure out the diversity of cold worlds? There is a sample of cold brown dwarfs that are, that I've been studying that I have JWST data on that showcase how cold brown dwarfs that are more like Jupiter are going to look different from each other. This is showing you a color magnitude diagram, like a Hertzberg-Russell diagram, where there's color on the x-axis and there's absolute magnitude on the y. And I've been these objects into temperatures and I'm getting JWST spectra for all of the objects highlighted for you with black circles. I'm hoping that in looking at it, I'm going to see all sorts of diversity due to a spreading clouds, a spreading chemistry or spread in age. So here's some results. This is a model of what I might be looking for. And I'm looking at the peak of this spectral energy distribution where it says JWST near spec G395H. And here are the results that I'm showing you guys kind of for the first time. No one else has seen these. In black is the data I got from JWST. In blue is what the model is telling me should be there. It should be astonished the model is even predicting a lot of the chemistry that we're seeing. I'm pretty astounded and the model predicts things that aren't in the data and the data has things in it that are clearly not in the model. Here's another example. This one's even a better fit. It's a warmer object and you can compare and contrast what these two things look like relative to each other. All of these lines are legitimate and real. All right. Diversity is a thing. So let me pull back and conclude for you guys. Brown dwarfs are an exciting class of objects. I know this was a very high level talk but again, this is some of the fodder for this colloquium. So hopefully you're going to walk away thinking, oh wow, brown dwarfs are kind of complicated objects but they teach you so much and they're big with JWST. So chemistry wise, the C to O ratio should not be anybody's holy grail right now because we haven't figured out the clouds to understand how to back out that carbon. With the clouds, you really need the mid-infrared data but once you have it, you can actually constrain the cloud properties. You can break them down into what kind of silicates they might be, phosphorate, esthetic, quartz. All of that can be solved once you have the mid-infrared data. We are certainly doing it but remember that young objects are more variable and the viewing angle of the object is really important. And then there's diversity. I think much is going to be revealed with JWST data on cold brown dwarfs so stay tuned. You will have cold brown dwarfs all over your press in the coming months, in the coming year. JWST is targeting not just, I have my program, there's several other programs that are going to have very splashy results on brown dwarfs. Okay, I'll stop there and take any questions that you guys have. That is just really fascinating. I'm really excited about how JWST is showing your models. That fit is amazing. We did have a lot of questions coming in during the talk which I didn't want to interrupt but I think there's some great ones. Also, if you have other questions that you're thinking of now, please put them in the Q&A and we will try to answer as many as we can. One of the first was people were wondering if brown dwarfs have orbiting planets. Excellent question. We wouldn't call them planets. This is where that definition gets all messy. So the one of the very, very, very first directly imaged quote unquote planet was this object called 2MAS 1207B. Now that's never really getting the recognition that it deserves for being the first directly imaged exoplanet because it's orbiting a brown dwarf and because of that it's considered a binary system rather than a planetary system. In order to find a planet around a brown dwarf you'd really need for it to break into that spot I kept showing this mass ratio plot. You want it to have a mass ratio that's super low. So basically you want to find Earth around brown dwarfs. And I am working on a bunch of lines using this Perkins telescope that my colleagues at Boston University are leading and in that we're actually monitoring brown dwarfs for terrestrial rocky planets. We think they might be there and if they are there I think we would call those planetary systems. But again the word planets all muddled. Agreed. Super agreed. An interesting question I thought was someone saying how significant are brown dwarfs to the contribution of dark matter? Back in the day when brown dwarfs were first theorized this is like the 1950s and then the 60s and the 70s when people were searching for them because it took decades before anybody detected one. They were theorized and then you couldn't find them because they're super faint and you needed infrared technology in order to find them. They were thought they were so sought after because they were thought to be the rationale behind dark matter that maybe the galaxy is just like bucket loads of brown dwarfs. But that whole idea has been debunked. So brown dwarfs are certainly not the contributing factor to dark matter. They're in much smaller abundance than was ever considered when they were first thought to be that potential character contributing to dark matter. So the answer is that they're not they are just not contributing to it. But it's a historic question. There was another one about to brown dwarfs form in the same type of nebula as main sequence stars. Yeah the um I have another let me see if I can play it for you. I have to find it. So stars form backup. These are half backup slides and just half slides that that don't fit this one. Let me see if I can skip and then play. So this is going to be a little oops. This is a little video that's going to fly away from the sun and show you hopefully. And it's going to fly away and it's going to show you all these star forming regions that exist in the solar vicinity. And those two brown dwarfs for instance that talked about the four starite clouds being dominated on them. Simple 136 and 2139 are formed out of the same stuff that formed the Korean and near nebula. Now in this video I'm flying away from the sun and I'm going to arrive a couple hundred light years away and see all that structure there. All of that over density. All of those are clusters and star forming regions. All of those stars in there form from the same giant molecular cloud that breaks down fragments and then holds on to them. And the brown dwarfs are just as much a part of that. So that's why we think that if you were to get the C to O ratio you would be able to back out the it should look the same as all the stars do because they all form from the same natal environment. Very cool. Now I make move if you can see them all moving. It shows how they're moving over time and dissipating. It's a really cool animation. Someone had also asked about if brown dwarfs could wander into our solar system and this is kind of answering that. But would the sun or Jupiter keep the dwarf away from our own solar system? Oh these are such great questions. So there is a project that one of my undergrads is working on and it's on what's called stellar flybys. And believe it or not stellar flybys is a pretty common occurrence and actually in one million years there's going to be a stellar flyby. A star called Lisa 710 is going to fly through our solar system at about 16,000 AU which is well within the Oort cloud where we have all of our cometary bodies. 70,000 years ago a brown dwarf actually a low mass star that's almost a brown dwarf that's carrying a brown dwarf companion with it flew through the solar system at 60,000 astronomical units so again through the Oort cloud. Now nothing has flown close enough to disrupt the planets in our solar system but these objects have flown through the Oort cloud and when you fly through the Oort cloud when you fly through the Oort cloud you disrupt those objects which could send cometary material into the inner solar system. That's the thing you have to worry about. We're not fully sure what the damage really would be. It takes a lot of modeling to figure that out. Right now it doesn't look like it could be that bad but we don't know how to integrate over time and dissipate the material. There is some thoughts that some of the material in the outer solar like the extreme Kuiper belt might be showing signatures of being perturbed due to a stellar flyby like this one that I'm talking about from this low mass star that was carrying a brown dwarf. Cool and then I have a couple of quick questions that you could probably answer in a word or two. Is a hot Jupiter a brown dwarf? No but it has the same temperature of a brown dwarf because it's usually a half a Jupiter mass, a Jupiter mass and brown dwarfs are usually not categorized that low but they have the same temperature so they should be studied together. And what's the difference between a gas and a cloud? I think you were kind of using them interchangeably in the discussion. Oh okay yeah well gas is the material. You have gas and dust and the gas and dust make up the cloud. And so if I was saying gas interchangeably it probably meant that I was referring to that component of the cloud as opposed to the dust. So sometimes I'll say gas and dust. If I'm talking about the gas in the cloud the gas is the major component that ends up getting compressed and turning into stars. Well the dust is too. They come together. Just depends on what aspect of the star formation process we're talking about. Have brown dwarfs been detected outside of our Milky Way? Oh wow no not that. I mean I of all people I should really be able to answer this for sure for you. Micro-lensing has probably detected the farthest brown dwarfs but nothing outside of our solar system to date. There is one potential planet detected outside of our solar system but otherwise it's really hard to get to these low mass things. You don't detect them directly. You detect them because you'd watch the light change somehow. And so micro-lensing is kind of the process by which that's the only way I can think you can get outside the solar system. I mean outside of our Milky Way. We still have about nine questions coming in so I wanted to check in with you if you're okay with answering some more. Yeah sure. Okay how do brown dwarfs end their lives? Ooh they don't. That's the crazy thing about them. They never go anywhere. They cool like a rock in like an ember plucked from a fire but unlike stars, main sequence stars and even that low mass stars also they're brown. They don't go planetary nebula and brown dwarfs just cool. They just keep cooling, cooling, cooling. They could start looking like a star. They go through looking like Jupiter and they end up looking like just some completely dim featureless thing. So when the universe ends it's going to be chock full. Every brown dwarf that has ever existed is still around. I can't say the same thing for stars. That's nuts. So one of the interesting ones that people are asking about is do brown dwarfs kind of give out any different kind of radiation? They don't give out different radiation but they do radiate primarily in the infrared which is why we have to look in the infrared for them and so in that way it's a very specific kind of research study. Like I have to be an infrared scientist to be a brown dwarf scientist. I can't really be a radio astronomer and be a brown dwarf astronomer because I'm just not going to get any information from my objects. I kind of have to hang out in the mid-infrared or the near-infrared as a scientist. So it's not different. It's just very specific. Okay so here's an interesting one about chirality if there's somehow involved in the study of brown dwarfs. What was the word? chirality like the right-handed and left-handed. Oh no I don't know how that could get involved. I also didn't know that word chirality. It means either you're right-handed or left-handed? It's the type of element of the chemistry like on earth. I forget which one there is that's either right or left that those are the only types that you can find on earth and so if you find one the other type you can determine that. So the one thing that the one thing that we go with is that there's uniformity to chemistry. That whatever you find here you should be able to find somewhere else in the galaxy. The one thing that does change is older objects were born when it was the lower amount of metals around and FYI you guys probably know this but astronomers consider anything heavier than hydrogen and helium maybe we get helium in there to be a metal. So when things are considered metal poor you can be carbon deficient like metals are not what your standard metals are that you learn in chemistry for an astronomer. So things that were formed really early on in the galaxy were considered metal poor which means that you're not going to have as much carbon bearing species so methane will be different, CO will be different. I showed you so much CO and methane and ammonia in these data but just imagine if you don't have as much of that available the objects will start to look quite different. And we actually are running out of time so I wanted to just compress one more last question from Susan Miller. You compare the mass of brown dwarfs to Jupiter what about their size are they very compact and generally white dwarfs, brown dwarfs, black dwarfs are they completely different? Oh there is a relationship between white dwarfs and brown dwarfs because they're both degenerate but they're degenerate in slightly different ways the white dwarfs go degenerate at a higher mass than the brown dwarfs do. Brown dwarfs are degenerate at a lower mass brown dwarfs do have a radius compactness to them for the most part brown dwarfs have a Jupiter radius. All brown dwarfs kind of cap out on a Jupiter radii so Jupiter radius is like a pretty standard value that we use. Great questions you guys were paying attention I'm glad that it seems like you caught quite a bit of that high level public talk. We do have a great group here it's so I wish we could get to all of them but thanks for putting in your questions and Jackie thank you for your talk that was really amazing and seeing that JWSTD is just really exciting. It's good stuff yeah I'm glad I got to show it to all of you there's more coming in there was almost a spectrum I was going to add in that I was getting right when I was getting on the call but I don't understand it they it's not ready yet it's not fully reduced so it's coming up more data more data more interesting chemistry always good I'll stop sharing all right thank you so much Jackie this is just absolutely great and thank you out there everyone for tuning in and as Dave noted in the chat you better find this webinar as well as many others on the night sky network website and on the night sky network YouTube channel so please join us for our next webinar on Tuesday November 15th when Dr. Francis Halzen from the University of Wisconsin at Madison will share with us about the ice cube project at the South Pole which is using neutrinos to help understand the most violent processes in the universe so we're kind of going from something that is rather mild I guess you know brown dwarfs and aren't particularly violent to you know some of the highest energy objects in the universe so keep looking up and we'll see everyone next month take care everyone yeah thanks again thank you so much Jackie this is