 Okay, every month we highlight an activity related to the webinar topic. This month we're looking at extra solar planets. Vivian White has this month's activity, which is also found in the NSN Planet Quest Outreach Toolkit. Vivian. Hi everybody. It's great to see everyone out there from all over the U.S., glad to be here with you. Tonight I want to talk to you a little bit about the Planet Quest observing cards. These are one of our more recent Toolkit editions and these are fabulous for talking about extra solar planets and the possibility of aliens while we're observing. So I know when I observe it's not always the first thing, because you can point out maybe a planet in the night sky that has planets around it, but it's not one of the first things that comes up when I think about observing, but it is a big question that I get from the public about aliens and what are the chances. So we created these. There are, I think, 14 different cards that talk about lots of different types of objects that we observe, moons, globular clusters, open clusters. On the front page it gives you some information about them. The back of the front page here gives you tips for the cards, including this little symbol here. It's a PQ and any of the tips on the cards that have that symbol are related to extra solar planets or the search for life in the universe. So I wanted to mention that we also have them as a red. You can download them as a PDF and use them on your, some kind of device, any device you like. It gives you pictures of what like M13 looks like here or where globular clusters are in the night sky. And it's done by the type of objects that you are looking at. So for example, let's say double stars, of course it's got a few of them, but then it talks about planets that have been found orbiting double stars, for example. So these are a great resource. You can download them. We have copies of many of them. Many of you have been sent the actual set, but you could download the cards yourself from the link that Dave just put in the chat. So it's, you go to the night sky network website. And if you just go to downloads, resource downloads, you could find it there. They're called the planet quest cards. So I encourage you to use them when you're talking about extra solar planets at the telescope. Okay. Fantastic. Thank you, Vivian. And now for the featured program, Dr. Tabitha Tabiboyajian is an astronomer and astrophysicist on faculty of Louisiana State University. Dr. Brijajian is active in the astronomical fields of stellar interferometry, stellar spectroscopy, exoplanet research and high angular resolution astronomy, all particularly at optical and infrared wavelengths. She was the lead author of the September 2015 paper, Where's the Flux? Which investigated the highly unusual light curve of KIC 8462852. The star is colloquially known as Tabistar in her honor. So please welcome Dr. Tabitha Biyajian. And I think she's here. I know she went to go check on her kids. There she is. Oh, and you're muted. Okay. There you go. All set? We're all set. Okay. Thank you for the introduction. And it's, I second Vivian's words on it. It's really awesome to see all the people from around the country that tune in to listen to this program. That's pretty amazing. I'm going to share my screen and talk to you about an object. Here we go. Thank. All right. Everybody can see this. Looks great. Thank you. Okay. Now I just have windows on top of it. Oh, go away. Can you see the windows on top of it? All right. I think we're all good. And you can hear me. Okay. Yeah, we can hear you fine. All right, good. So what is staring you in the face right now is the project image for a star that I've been studying for quite a few years now. And, and it symbolizes a few things. The first thing is, is that this, this star was spotted by the human eye. So it was not, it was found in data sets that would, you know, very, very large data sets and, but it was the human eye that actually like saw the features in it and identified it as quite unusual, even though they're very, very large. And what the human eye saw was what you see in the pupil are these like very strange fluctuations up and down in the star's light. And it also symbolizes the call to action on what we want to do to study the stars. We wanted to watch it and wait for it to do these crazy things that we saw again. So we can learn more about what was going on. And so a nickname that we created in the very beginning was this was the WTF star or the where's the flux star where flux stands for brightness in this case. So I would like to start kind of in the very beginning and my slight advance isn't working. Okay. And in 1995, and so I saw there was a few groups out there that have high school students and they were probably born after 1995. But in the grand scheme of things, 1995 wasn't that long ago. It was, you know, just over 20 years ago. And this is when the first planet was detected. And this was kind of like a really big deal to the whole world because it kind of put us one step closer to the age old question is, you know, are we alone? Is there anybody out there? Meaning that, you know, our son wasn't the only star out there with planets that went around it. There were other planets around other stars, meaning that there could be life around other stars a lot more than there could be, you know, pre 1995. And so this was a whole, you know, revelation in, you know, not just astronomy, but, you know, just humankind in general was this landmark. And so the image that I'm showing here is a animation of the history of exoplanet detection. You can see the ticker mark over in the right hand side. And the first few points for the first couple hundred years are all solar system planets and when they're discovered. And then there starts to be other points that populate this graph and they're different color coded depending on their detection method, which you can see over on the lower right hand side. And what you can see the orbital period down on the bottom axis in years going to the right to longer orbital periods and the planet mass over here on the, you know, up down left hand side where you have higher masses going up to the top of the graph, that each planet detection method, right? So each color of these plots, plotted points, they kind of populate a different region of this whole parameter space, but nothing has really come to sample anything that's very similar to planets in our own solar system. And they're also very unique at identifying planets in different kind of regions. So you see like there's a whole lot of red dots that concentrate over on the kind of center left hand side, whereas a whole lot of the green dots are up in the upper right and a lot of the blue dots are up in the far, far upper right. I'd like to talk about or focus in more on the transit detection method. So these are the planets that are detected or that are illustrated here in red, and we're looking at kind of the smallest masses planets here and the ones that are, you know, pretty similar to orbital period of less than a year or so. And so 1995 was the landmark discovery that I said of the first planet ever detected in our solar or outside of our solar system. It was six years later where the first transiting planet ever detected. So those are those red dots and I like to make a joke and say like, this is the picture that was taken, which it's really not the picture that was taken. This was an artist's rendition of the picture of the system. This system was unlike anything that we know in our own solar system. This is a kind of solar type star and the planet that was going around it had an orbital period of about three days. And so it was just being blasted by the star light from its host star and it had this huge kind of, you know, exhaust tail that, you know, expended around it as it was orbiting its planet. And you may have heard of the term transiting planet because of the Kepler mission. And Kepler mission was a very simple mission that was designed to identify the occurrence rate of Earth-like planets around sunlight stars. And what it did was it stared at a single piece of sky for four years straight, taking measurement every 30 minutes of over 150,000 stars. And it did this very, very precisely. And what it was looking for is looking for the chance of a planet's orbit being aligned in our line of sight and periodically crossing in front of its host star and blocking out a part of its light. So you can see this in the little dip shape in what we call a light curve here. And so the Kepler mission and now it's called the K2 mission because the Kepler mission has now been repurposed. And well, that whole story is probably another talk all in itself. But it still goes on, but it doesn't it doesn't look at the same field in itself. It's found thousands of transiting planets and it's it's answered the question pretty much that, you know, pretty much planets are everywhere. The galaxy is littered with them. And so when you're looking at what we call a light curve, so this is the stars brightness measured over time and say you have a planet that's aligned in our line of sight. If you're looking at the same kind of star and you change the size of a planet, you can imagine that a larger planet will make a larger dip in front of a star and a smaller planet would make a smaller dip in front of the star. So this is what this graph is showing here. So this is the most simplest way to show what actually goes on. But of course, astrophysics makes things a bit more complicated for us. And and both the stars have spots and stars stars have pulsations and all sorts of other things. And sometimes you don't just have one planet. You have two planets or three or four, even up to seven transiting planets. I think is the record of of what has been observed in our solar system. So things can get pretty complicated. And with this in mind, we came up with the my colleague, Deborah Fisher, came up with the the idea to feed all this data that was coming in from the Kepler Space Telescope. All of these light curves of 150,000 stars into a wet interface and have people volunteers come and help us classify these light curves and see if automated algorithms would actually miss something. And so this is this is essentially what they're looking for. And it's kind of, you know, man versus machine kind of gamble. And and this was called the planet hunters interface. And this is a program that's still going on today. It's it's part of the universe program. And I'd like to highlight some of the really cool things that have come out of planet hunters. The first one is quite, I mean, this is like the funnest one, I think. What are the funnest ones? There are lots of really fun ones to talk about. The discovery of pH 1b, which we now call it. So this is the first confirmed planet from the planet hunters citizen science program. And this is a planet in what we call a circum binary system. And so what that means is that you have a binary stars. These are two stars that are gravitationally locked together and they orbit each other in about a couple of weeks. And then around these two stars that are going around each other a couple of weeks, you have a planet that's also going around both of those stars in about 100 days. And this all of these things are all lined up in our line of sight. And so we see all of these eclipses happening. So this is what you see over here on the left hand side. You see the eclipse of the two stars and also the planet itself. And what you see over here on the right hand side is actually like one of the snapshots of one of the top windows is kind of a discussion forum in the planet hunters interface, showing how just amateur astronomers, people just interested in this sort of science, you know, was looking through this data, you know, saw the star and started, you know, just kind of brainstorming on what it could be. And this was many, many months before the NASA team came out with the result from another star that was discovered as well. And so this one in particular is really cool because it's a circum binary planet in a quadruple system. Because so you have the two stars, the close binary, the planet going around that. And then you have another binary star that's very far out and distant, but it's still gravitationally bound to it. And so you have four stars in one planet in the same system. So that's pretty awesome to talk about. Another thing is that I like to talk about is, well, this is kind of bragging rights. This graph over here on the right-hand side, what I'm showing here is a planet orbital period on the x-axis and planet radius on the y-axis. And all of the black dots that you see there are the planets that have come out of the algorithms, the automated search routines to find planets. And the position of the Earth and the position of Jupiter are graphed here. So this is where Earth is and Jupiter is over here. The red dots there are points or are planets that have been missed by the automated routines for one reason or another. Like, and they have been identified by planet hunters. And so this is really neat. Like planet hunters have identified a bunch of the black dots. It's not, you know, the majority of them, but I don't plot those there because it would be kind of redundant. These red points here, during the really sweet spot, I think, for, you know, for what we would be really interested in finding, you know, cool planets that, you know, could have liquid water and possibly life on them. And so planet hunters is very uniquely sensitive to these kind of unique finds. What else planet hunters is very good at is finding things that you weren't really looking for. And this is what I alluded to in the very beginning is that you have humanized looking at data where a computer will only find exactly what you tell it to find. But what if you're looking for something else or what if you don't know what else is really cool that's in the data? And so this is when planet hunters or volunteers came across this one star KIC8462852. And in May 2009, they saw this graph right here. So this is a light curve again. This is Kepler data where you have time and days in the bottom axis and the star's brightness on the y-axis. And the user started to comment that this feature looked like a planet transit. So remember the planet was going in front of the surface of the star, it blocked out a bit of the star's light. This blocked about the same amount of the star's light, but instead of a typical transit duration of a few hours, this lasted for over a week. And the volunteers noted this. And they also noted that instead of having a very clean U-shape dip in the star's light, there was this kind of strange slope over here on the left-hand side, which indicates that whatever is going in front of the star wasn't circular like a planet. And so moving on, there was really nothing that came on for a couple of years. Until March of 2011, where there is this very, very sharp drop in brightness to 15%. Now, this gradually went down over the course of a week to 15%, and then it snapped back up to normal. And then there was nothing after that. Now, this is very, very huge and very, very unexpected. And again, this triggered a lot of conversations on the planet hunter's discussion forum called Talk. Again, there wasn't much happening for a couple of years. This is the entire four years that Kepler observed KSC 8462852. You can see in the last three months or so, the star went completely nuts. And in February of 2013, we have 100 days of brightness fluctuations that are completely unprecedented given the rest of the light curve or any other light curves that we've seen in the Kepler database. So we have many, many drops. Some are very sharp and some are very broad. There are ups and downs within some of these drops, almost like there's, you know, a few events that are superimposed on top of each other. And the deepest point, the deepest drop in the star's brightness at this point goes down to over 20%. So this means that it's something over a thousand times the size of our own Earth was crossing in front of the star and blocking the star's light. And so this was, I'd say alarming to say the least. And so the citizen scientists came to me and they said, OK, well, you know, we're really stumped, you know, what is this? And this was something that any scientist who still sees this still says, oh, well, you know, that's got to be bad data. I've never seen anything like this, but we looked really hard. Yeah, the NASA team looked and it all checked out to be good. So there's had to be something astrophysical happening to cause these brightness variations in the star. We didn't know what it was. And so at that point, you know, we decided that we could go out and get some auxiliary data to try and, you know, come up with some solutions on what was going on. And so we did that. And we came up with, you know, a number of theories. We came up with, you know, ideas that, OK, well, maybe the star was very young and it still had this cloud of dust and debris that it was made from that was still surrounding and it had quite blown that away. Perhaps it was an asteroid belt similar to our own, but maybe much bigger. And this was kind of, you know, going in and out of our line of sight, blocking the star's light. There's ideas of, OK, well, maybe there's some, you know, giant, you know, Saturn on steroids, super Saturn kind of system. Then maybe that's going in front of the star and blocking the star's light in weird ways. Or perhaps you have, you know, some, you know, very, very, you know, like the environment of, you know, in some catastrophic collision of planets. And we're seeing kind of debris of, of, you know, two bodies that are smashed together and kind of blown each other to bits. And this is what's going in front of the star and blocking out the light in very weird ways. And numerous, numerous other ones that I'm not mentioning here. But every single idea that we, we had, you know, come up and propose had been inconsistent with the majority of the data that we had in hand. And the one that actually came to the top was that maybe there was some swarm of comets that was broken up, fragmented in, in, you know, some, some event previously. And they were headed down towards the star. And this, this is what was causing the blockage of the light. When the comets came close to the star, they would out gas and get really big and block a lot of the star's light. But as they would go further away from the star, you would not see any infrared excess. So like all of the previous theories that I had mentioned had, they had issues being consistent with the data, because if you invoke dust or any kind of dust surrounding a star, then you would have the star light hit the dust and the dust re-radiate in the infrared. And we see this in astronomy a lot all the time. And, and the star did not have any anomalous infrared observations. So the, the way around it was to invoke comets. And so this way you have something on an egg shaped orbit where it's been a very little time in front of the star and then most of its time away from the star and you can get around it in this way. Well, I mean, this, this kind of idea came together at the very, very ends of our paper of really trying to, to scramble and put some things together and get it out the door. And this actually caught some attention of the media. And I actually, I had a bit of fun with this, you know, because comets on our own solar system as they, you know, track down towards the sun, they had, they leave this kind of debris in their way. And when Earth goes through this kind of leftover debris trail, this is how we get meteor showers. And I had, I had fun with this, you know, imagining, I was like, yeah, well, what if you're planning that solar system and you went through like this giant comet swarmed debris tail, you know, it'd just be like a galactic sized kind of, you know, meteor shower. Anyway, yeah, that was fun. But things really got crazy a month later when, when this article came out that, that shared the news that we had written the proposal to look at the star system for signs of ET. And, well, the idea here is that my colleague Jason Wright was, was doing a survey of stars in the Kepler field and he was, he was saying that, OK, well, you know, he was testing the theory by Luke Arnold saying Kepler's extreme precision would allow you to detect very complex structures, say, you know, built by ET in Kepler data. And he showed very, you know, he showed very, you know, good examples of things that Kepler observed that we would never even dreamed of, but there was all a physical explanation for every single one of them. But then this one didn't really have it. And so we decided to follow up this one, writing a proposal for it. And, and the news of this got out in the said previous article. And so you may be asking what I'm talking about. If you have some sort of extraterrestrial civilization that's very advanced technologically, they could build giant solar panels to to harness energy from their host star. They could even, you know, build giant structures to terraform and live on these surfaces and these these massive, massive things, you know, imagine them swirling around the star and they can really block out the star's light in very strange ways. I just want to note right now that this is a very, very last resort hypothesis. This was an interesting idea to test and it ended at that point. Right. But we need getting observations. We'd be able to learn something about it. So what. No, it's not moving forward. Sorry. OK, some some points to that last hypothesis is Professor Carl Sagan's extraordinary claims require extraordinary evidence. This is nothing that we claim. This is proposal that we wrote. So we want to take a closer look. You know what that proposal got rejected and that's OK. We just need to reformulate our reasoning a bit more and we finally got time for it. Another point in that is that with three parameters, I can fit an elephant. This means that, you know, the more free parameters that you put into a model, you can fit pretty much anything to your data. So if you're invoking E.T., then you can pretty much explain any sort of observations that you have because you really don't have any limits on those. And over here to write, I have a kind of tongue in cheek explanation for this. People want to know what a light curve would look like. What a star's light output would look like if you have a non-circular object there. You can maybe tell by the bottom axis of the graph. Here you have Santa and his sleigh. This is on December 25th. You see how the star's light drops very radically when it's dropping packages off. It kind of goes up a little bit and down. And see how the resulting shape of this light curve, right, isn't smooth and symmetric like a planet would across it. And so with three parameters, you can fit an elephant. This is kind of the guts of all of that. But still even, you know, with these quotes in mind, I would like to remind everybody that there is something called waste heat. If you have an extraterrestrial civilization that is gathering energy to use for their home planet or, you know, terraforming or something like that, you have a lot of energy that is being used. And this energy is going to produce heat somehow. So this is why you're talking your cell phone for a long time. It heats up or your laptop gets hot on your lap. You know, the same thing goes, this image right here is a house that you can see in invisible light, which our eyes can detect. And on the right hand side, you can pay these companies to go see, to look at your house in infrared light to see how well your insulation is on the windows, the roof, and your doors, et cetera. And you can see where heat is leaking out the most. The same idea goes for this star here. You don't have any dust around the star. We don't see any infrared excess. That was the most problematic thing of our natural explanations to explain it. We don't have any infrared excess for this star. That means that we don't have any waste heat for this star. So there's no real motivation for a, you know, to invoke a Dyson sphere, just given these thoughts straight out. But again, you know, given, you know, three parameters, you can fit an elephant. The easiest explanation for that is, OK, well, what if you have your house and it's perfectly insulated and you just open the back door and so you can't see any of the infrared light because it's being blocked by the rest of it? All right. So the amongst all this kind of, you know, all these different theories that were coming out, really hoping that, you know, something that could enlighten us to some other, some clues of what was going on. A study came out with the Harvard plate stacks, and these are old photographic plates, these glass plates that were exposed, going back to, you know, the late 1800s. And these archives are available in a digitized form and in and you can go and actually like, you know, make measurements yourself. If you're one of the 10 people in the world who know how to do that. An astronomer, Brad Schaefer, does know how to do that. He took the digitized form and he made some eye measurements. And he looked back and he was interested in what the star was doing. You know, not the four years that Kepler observed it in the 2000s, but what was it what it was doing over the past hundred years? Now, the resolution and the the measurement precision of this data wasn't very good. So he bind it in five year bends. And this is what you see as these blue points here. And so this is a hundred years worth of data. The gray points are comparison stars. So there are stars that are near by it. And you can see that they're relatively flat. The blue dots right here are the target star in question, which shows us that in 1990, the star is 20 percent dimmer than it was. In 1890. And this was really, really surprising result to come out. And, you know, this kind of made you think, OK, well, if you're invoking comments and we're talking about thousands of comments already that just happened to pass in front of the star and us to be blocking out the lights. And Occam's razor says, OK, well, if you have the short term dips that we see in Kepler and you also have this long term dimming, then they must be caused by the same phenomenon. And so if you invoke the same thing, then you're you're talking about over, you know, a million comments or so that are perfectly orchestrated default in between us and the star over this hundred year time frame, which seems even more improbable than the previous proposition. And so that kind of brings us to where we are now. So where's the flux again? We have this Kepler light curve for KIC8462852. So this is the full four years of the light curve where you see these kind of very strange shaped short term dips. Nothing really periodic about it in this very big cluster over here on the left hand side. And these are zoom ins of the big cluster showing the very dynamic range of the observations. And then you also see this very long term variability. So these secular decline over a hundred years and then over a four year time frame, I show it over here showing that the star dropped over four years, just 3% over that four years. Now what I'm not showing here are several other studies that showed these same kind of secular declines over, you know, time periods of history because the one observation of the short term dips was that was pretty capturing enough. The 100 year secular decline was very controversial at first. The stars don't do that. And to make that kind of claim along with the other one was very controversial but then it came out over and over again that that was something that persisted in many independent data sets. And so what do you do with something like this? You have two very, very unique things that are, you know, you've never seen before, you don't know how to predict when it will happen again because there's no periodicity in it. And so we called on help from several avenues. The very first one to step up was from the AAVSO which I'm sure you're all familiar with here. There are dozens and dozens of people who stepped up and started observing the star with their telescopes and submitting them to the AAVSO. The show's the past three years of data. And this was absolutely amazing to see come in. But we realized really quickly is that what we really wanted to see is we wanted to catch one of these dips in real time. And knowing that each observer here is very good independently but when you put all these observations together you have a scatter of, you know, around 10 or 20%, which isn't gonna let you alert yourself to any large dips. And I'll just say that the star is flat brightness throughout this whole time until this point right here. And so you can kind of see what I mean. And so what we decided to do was, well, pretty much the only thing we could do is use the last cumbers observatory which is an amazing network of 21 telescopes that basically all work together to keep you like as a single instrument to keep you in the dark at all times. So basically when the sun rises in one place it's already dark in another place and your request goes, you know, automatically to another telescope at another location. And so you can continuously watch, keep your eyes on the target 24 hours a day if need be. And this was key because we did not know when the star was gonna do what it was doing again. And so we actually crowdfunded observations through this network. And this was, you know, building a team of interested, you know, supporters to make these observations and just see what was going on if we didn't look we would never know. And so this is kind of what the day to look like for very, very, very long time. We just kind of sat and waited for things to happen. And so here I have day and then brightness potted for you. And then in May of 2017 we saw the brightness start to go down. And so when this happens we did what everyone does these days and we yelled it really loud on Twitter and other things of course. But to trigger more intense high, like high resolution spectroscopic, anything that we could get observations to help us study what was happening. Like whenever it was going from that star we could learn about it a lot more detail if we caught it in one of these events. And that's what this was. This was the first time ever we had ever done this. And so this was by wall after that first day. So this is after the first 12 hours or so and it definitely grew after this and I had to move it to another wall. But we got lots and lots and lots of triggered observations from that very first step in May of 2017. And we're still going through a lot of it trying to learn more detail what we have. But I wanna give you a brief review on what we learned. First is just an overview of what happened in May of 2017, what I showed you over here. So these colors are different observatories and here we have it again day right here and this is your normalized flux. This is May of 2017, this is December of 2017. What we have are one, two, three, four large dips in 2017. And you can also see that their name, their name because the Kickstarter backers in our program, that was one of the rewards is that you get to nominate and then vote on a name. And so there are stories behind that, I can talk about it later if you like but in the interest of time we'll move on. But you also see this kind of like blip up above the normal brightness. Now this is kind of expected maybe because we know that the stars brightness changes over long periods of time. But here we kind of nicknamed that Watt as the Angkor Temple Watt, okay. And wondering if this is the new normal, this is kind of like up to kind of current observations here we had in March of this year, we had Carl Soup and Evangeline. These are the two deepest ones that we've seen since Kepler. We wrote a paper on this a couple of months ago which came out, has a ton of collaborators, people from AVSO, professional astronomers, everybody in collaboration with, yeah, everybody trying to put this all together. It was quite a remarkable work. And I'd like to highlight the main results. The first and foremost, what I'm showing here on the right hand side is LC. So this is the dip LC, the May 2017 dip. And here the color indicates the wavelength or the filter that we used in the observations. So blue and then here's kind of yellow light and here's red light. And what's pretty noticeable here is that the blue light dips more than the red light. And so we call this being chromatic, meaning that whatever is coming in front of the star and blocking like blocks the blue light better than the red. And this is consistent with any kind of optically thin sub-bicron size dust. Along with these results, we're able to prove this is not an artifact of Kepler, which some people still had in mind that it was still a fake deal, that there is no clear pattern that has come up yet. There's been some prospects of that but we haven't really narrowed down on anything that's very clear. All the other observations that I showed you, which figured observations are very unimpressive. Like if we look at observations prior to this during the dip or polarization or even infrared excess, we see nothing that is out of the ordinary. So that's quite interesting. It looks like dust, but we can't see the dust still in the infrared or in the spectra. Another results that have been coming out is that this secular decline that we showed, this is AAVSO data for the past few years. This has been in 20-day been. So you can't really see the LC family in dips, which is right here, where this kind of spike with a four spokes in it is, yeah, so this thing right here. But what you can see is that the different colors, so these are different filters plotted here, they all have the same shape but the blue and the green are more prominent going down than the red and the orange. So this is also an indication that the secular domain is also chromatic. And what was also shown in a recent paper by Brad Schaffer is that he was curious to at what point, we see the star going down, down, down, at what point did we make any of these observations in modern time and it's going down and it's in its decline? And they found out that you can calibrate these data with historic data and see that there was at least 12% of the star that was covered at the time of recent observations. And so in the interest of time, in summary, our current understanding with all this in mind, with all these new observations that come in that everything looks like the variability is probably due to dust. And people are like, well, wow, really? Really, this is dust. And yes, it looks like dust. And the reason why I say really is that if you're listening before when I said that there are all these ideas that we had in the very beginning and they didn't work because if you put dust around a star then you'll have a glow in the infrared. So this is still kind of problematic in a sense but we can possibly get it to work and we're still kind of working that out. The issues are that it looks like there is dust that's coming in front of us in the star but we're not really sure what's generating the dust and how it's being replenished meaning that if you have some dust source in front of the star and the star's radiation pressure would blow out the dust in a very short amount of time. So you have to have some source of the dust that was recreating the dust as time goes on and recreating it over many years at a time. So we're looking ahead and we'd really like to continue the photometric monitoring to detect and characterize more of the dips. We want some really big dips so we can really learn what's going on and the long-term dimming trends of course is very important and also characterizing the variability in the extremes. So we have a lot of the parts of the electromagnetic spectrum that have not been sampled and that would be really interesting for many reasons. And there's also some extensive modeling that we think that do need to happen for any of the dust scenarios or also any scenarios that are not completely ruled out such as star spots. And I'd like to end with a quote from Jill Tarder saying that we need observations like a whole sky at all frequencies at all times to really understand our place here. And I'm gonna end it. There's our magical dust, all right. So I'm gonna end it on this note. Again, here is a website that we have or dedicated to the star, a link to Planet Hunters and a link to a subreddit that's specifically dedicated to the star. That's absolutely amazing. Moderators there do a really great job. There's Q&A pages. There's a lot of resources there that you can take advantage of. And so with that, I can take questions. All right, well, thank you very much. This is wonderful. And so we've got a couple of questions starting to come in. And so if anyone else has any questions, please remember to put them in the Q&A window. And so Daniel asked a while ago. And so you alluded to this, I think a little bit about some of the stellar processes that might be going on. And he suggested maybe it might be something like a coronal hole. Well, we've thought about star spots. There is, Falkal has written a paper on star spots and inhibiting convection and basically being able to suppress convection which also suppress the flux itself. And then we release itself over a gradual amount of time and this could possibly be a mechanism for the brightness variations. Our data that we have are inconsistent with this but the new data, so the analysis of the whole LC family of dips might be might be a little more to look out there. We still haven't done that part. Okay, so Kenneth asked if it's dust, could it be dust in interstellar space that is passing between the star and us? Maybe something similar to the Pleiades that maybe it's not within the system itself? Yeah, that's a very good question. And there are some people that are really keen on that. I myself can't really wrap my head on how the geometry would actually make it work. But saying that it could work because space is very, very big and you would have to have some very fine structure of dust, fine structure of dust that's also very dense and just going in front of that one star and no other stars. And so this is something orders of magnitude on scale in both directions that we have never observed before we can't ever observe in that sense. But we do have these different dust populations which to me seems to indicate that you're looking at dust that has to be created in some way. And so I think you really need to have the stellar radiation pressure to form these populations of the dust. And so my bet is still on being circumstellar but I don't think it's completely rolled out. Okay, so Michael asked a question very similar to this. So we have some people that are kind of riffing off of the dust idea, says would an extended accretion disk outside the active solar pressure region of the star be possible? Yeah, so an accretion disk or any sort of diskey type things that you would have especially to block 10, 20% of the star's light these are going to have a significant imprint on your infrared. So imagine the star light leaving the star as soon as it hits the accretion disk it's going to be absorbed and re-rated in the infrared. And so any type of diskey sort of thing you would be able to see an infrared excess and you would also be able to see that in these star's spectra as well. So we're thinking of some kind of very time dependent sort of thing and asymmetric in geometry. Okay, so Brad has one of his students he has a classroom of students watching tonight. And so Brad, one of his students asked what sort of dust been created by what process what would have these sorts of properties? Yeah, okay. So the short answer is we're still trying to figure that out. The picture that I paint in my head and this is truly a painted picture is that still invoking the comments here. And I realized that this scenario does have its issues. But imagine you have some swarm of smaller bodies and it's in the very elliptical orbit and as it comes closer to the star itself it starts heating up and it starts outgassing. And so this is the source of your dust itself and you'll have a whole population of particle sizes when it outgasses. So you'll have very small particles and much bigger particles. The smaller particles are gonna be outblown by the star's radiation pressure pretty quickly in a matter of days. The larger particles are gonna be able to remain in that sort of environment for much longer they're gonna be able to stick around. And as these objects orbit around the star then they'll kind of smear themselves out in the orbit. Okay, and we have an anonymous attendee asked would the dust make such a sharp dip signature? What would, is that what you would expect from dust? Would it be more, less steep I guess? Well, okay, so that is a very, very good question. There's a lot of things that we assume but the, so if you assume that's something that's completely opaque or if you're assuming something that's semi transparent or semi opaque they're gonna make a different feature if they cross in front of a star. And so you can put limits on things, on any sort of orbiting material kind of making these assumptions on how far out whatever clump of material it is orbiting the star based on its orbital speed and its opacity and the kind of gradient that it shows is like how much does it drop off with time? And so the shortest duration drop that we saw was in the Kepler data and that was around just less than half a day. We didn't see anything a briefer than that. And so that's not necessarily very, very short but other than that we can only give ourselves limits. Okay, so Brian asked a question and we're staying with the dust ideas here. So Brian asked, do a spectroscopic data show any chemical signatures that might hint at the type of dust? Our spectra are unimpressive. So we looked at spectra taken when the system was fluorescent versus when during LC if you remember that that the graph I showed with LC and the three different filters B and I and R there's three vertical lines in there. Those are when we took spectra and none of those spectra showed anything that was out of the ordinary during those times. Okay, and Brad asks of any RV studies been done to eliminate the possibility of dust orbiting another star that would cause the depths? I'm not quite sure what the another star was where we're looking at longer term radio velocity so spectroscopic measurements of this star to try and determine if there's any sort of longer period signals that we can tease out. Like we have a few measurements for over a couple of years but over the past year we've gotten several more due to the activity. And so we're working on those results right now but I'm not quite sure what you mean by another star. Yeah, I think that my interpretation of that would be maybe another star in line with that perhaps a red dwarf or something that is not quite as obvious and yeah. Okay, excuse me, so this star does have a companion or a star that's very close to it at least visually in our sky. And so this is a red dwarf star and so it's much less massive than this star. This star is about a thousand degrees hotter than our sun, it's an early F, about one and a half times more massive. This M dwarf as we call it, it's about just a tenth or a couple of tenths the mass of our own sun and many thousand times less bright than our own sun. So it's much, much, much fainter than KSC 846-852. So given that, even if you covered up that entire star full of some sort of blocking material, whatever have you, you can't get 20% of the combined light taken away from that. Okay, so Pete asked a question a little while ago and so you mentioned that there's a companion star, that there's a binary system and so he speculated could it be a binary system pulling matter from a companion? Well, we've ruled out the presence of very close companions from spectroscopic analysis, so through radio velocities and also through imaging, so just high resolution imaging. So this kind of rules out a lot of parameter space that you could imagine any sort of binary star, especially closely interacting binary stars, you would definitely, you would see that in the spectra, you would see spectra of two stars instead of just the one. Okay, well, I think we have time for one more question here and so we're gonna kind of go with something really fairly speculative here. So Chip asks, what about a dark matter filament passing between us and the star therefore not radiating in the infrared? Dude, proving dark matter's existence would be awesome. But yeah, I don't think we can go out on a limb with that one here and claim that's it. Dark matter isn't necessarily known to do this sort of thing, if anything. Well, we have mysteries enough just with the star all by itself and so there's been lots of interesting ideas that have been thrown out there. So if you could just go ahead and stop screen sharing and so we could come back to normal mode. So I'd like to thank you very much, Haby. This is really fascinating. We had some great questions and it's really interesting to see the process of science going through and seeing something that you can't explain and then trying to find ways to accumulate more data and really try to come up with an answer. And it's interesting the process, how this is really an exemplar of the process of science. Yeah, it's a really fun one and when you reflect on it, it's kind of, it's frustrating because this is not how I thought science would really go studying to be a scientist and publishing something that you just really, you're like, I don't know what this is. You would think that you'd come to results and that would be the most exciting part. But finding a true mystery and something that you can really kind of not know the answer not know the answer in the beginning kind of system. Yeah, it's the most intriguing kind of thing and there's so many serendipitous discoveries out there that the signal in this data is huge. Like it sticks out like a sore thumb and we wanted to found it if it wasn't for folks that were interested in just contributing some kind of science in some way and they flagged it and started talking about it and that's the only way that we knew about it all. It would still be sitting in the Kepler database if it wasn't for planet hunters. And I think it's really cool that it's really taking a community to be able to get all this data and try to come up with an answer. I think that that's marvelous. And what was it that Isaac Asimov said that many scientific discoveries begin with a statement? Well, that's funny. Yeah, that would work in this case. Well, that's all for tonight. I'd like to thank again, Dr. Boyajian for a great webinar. You'll be able to find this webinar along with many others on the Next Sky Network website in the Outreach Resources section. Each webinar's page also features additional resources and activities. We will post tonight's presentation on the Next Sky Network YouTube channel in the next few days. Thank you very much and stick around for our raffle.