 to introduce our venerable co-host and newly-mitted PhD candidate, Brett Morris. Yeah, that's awesome. It's a stressful experience. And you can be telling us all about the very interesting, and in some ways, enigmatic tabby star. So please welcome Brett. Alright, so today's theme is CSI Universe, right? I'm going to present to you a mystery. And I'm going to see if using our combined brain power we can solve this mystery. Are you up to the challenge? Yeah! Have you had enough fear? I'm going to get some more because we're going to do some science. We're going to talk about a star called Boyajin Star, or with this name that's kind of like a telephone number so nobody uses it. Boyajin Star is a lot easier. And in this talk, I'm going to cover what we know about this star and why we think it's weird, how we noticed that it was weird, and what you can do about it. There's going to be a call to action at the end. You need your help. Boyajin Star is this one right here. Can you tell that it's special? You are not astronomers. There's nothing special about that star. It's a normal star. It looks like all the other ones, but it's this one. If you measure its properties, you find that it's more massive than the Sun, but not more massive than most stars. There are other stars like that. It's got a bigger radius, proportionate to its larger mass. It's brighter, and it rotates pretty fast. It rotates almost once a day, a little bit faster. But beyond that, it seems like a perfectly normal star. If we look at its colors, if we look at its spectrum, it behaves just like all the other F stars. It's a type of star as an F star. And so we were a little bit puzzled when we started looking at data from the Kepler Space Telescope. I'm going to get to it in a second. And Professor Tadda Boyajian of Louisiana State University put together a paper saying, this star is weird, and we don't know what it's doing. That paper made a lot of weight, so you probably read about it in the Daily Mail, all over the news, because they think that this star is doing something peculiar that's not easy to explain. And so Dr. Boyajian was invited to give a TED Talk, which I encourage you to watch. That's her and her TED Talk. And so if you don't get enough of it for me, you can go home and learn more. And you can follow her on Twitter to get the most up-to-date updates on what's going on to the star. And when I mean up-to-date, I mean up to the second. The way that we found out that this star isn't weird is by using NASA's Kepler Space Telescope. Kepler was hunting for planets, and this is the mission that found all of those planets that you've heard about. The way that it did that was taking a picture of the sky and capturing a brightness measurement of 150,000 stars every 30 minutes. What it was doing by measuring brightness of stars was hunting for planets via what's called the transit method. Here's the sun, and up here in a moment, you're going to see Venus pass in front of the sun. Hopefully Kristen's laptop can handle the video. Maybe. There's a bug transiting. There it is. All right, thank you, Kristen. That's the planet Venus passing in front of the sun. We're going to look at it multiple times while I talk, so you can keep watching the pretty video. Venus is a pretty small planet, and you can see that here. We're close to Venus, so it actually appears bigger than it would if you were very, very far away. And as Venus passes in front of the sun from the Earth, you can see the disk of Venus blocking out light. For distant stars, we can't zoom in well enough to get wonderful views of those stars like this. And so we have to rely on just measurements of the total brightness of the star over time to find out if there are planets there. And as you can see, the planet's going to block out a little tiny bit of light. If you're looking very carefully, you can see that dip. That dip is what Kettler looked for. That dip gives you a few pieces of information. It's going to happen once a year for the planet's year, so every time it goes around, it's going to give you another dip. And that allows you to measure the orbital period of the planet. Another thing that you can measure is how big the planet is. Because it's planets bigger, it's going to block out more starlight. This is not a planet. This is the moon transiting in front of the sun by a spacecraft. And so it's not a perfect solar eclipse where the moon perfectly blocks out the sun, but you can see, you can imagine, if there were a much bigger planet orbiting a star, it would block out more light for you to measure the size of the planet. That's what Kettler was made to do. And it was very successful at finding exoplanets transiting stars. The kind of data that we talk about with Kettler are called light curves. This is a light curve. This is a measurement of brightness over time. This movie didn't label their axes. I should have done it for you. This is brightness over time. And you're watching as the planet passes in front of the star, the brightness dips a bit. And then when the planet passes off the star, the brightness goes back to normal. And that repeats every time the planet goes around in its orbit. Of course, real data don't look as good as this cartoon, right? There's all kinds of noise in there. The spacecraft occasionally hiccups when thrusters fire and it points its direction a little bit differently. And so your brightness is not as clean a measurement as this looks. As a result, it's kind of hard to analyze all of the data for 150,000 stars cleanly with a computer, writing an algorithm that can handle all of the noise in this data's trailer. So astronomers enlisted humans. There's a website called planethunters.org, which is still live and you can go to it now. You can stop paying attention to me and start finding planets right now. That's what you want to do. And not just at the bottom of your beard. And what you can do on this website is help scientists look for things that are weird. Because our computers are very good at looking for the things that we tell them to look for. The purpose of Kepler was to look for planets. We got good at telling Kepler how to find planets. There's someone in the front row who found 800 planets in Kepler. That's something you can do if you know what you're looking for. But looking for weird things is something that you can really only do by having a human look at light curves, which is a tedious task. But fortunately people like you are up to it. And so if you sign on to planethunters.org you'll get a screen like this and it teaches you how to look for things in light curves from Kepler data. What's going on here is that up at the top, this is our brightness measurement over time. So we've got brightness on this at some time here. You can't actually see it in the labels, but that's okay. And you can see that there are some dips in brightness here and here. They look periodic. That's a planet going around its star and blocking out light. If you saw a light curve like this, it asks you to highlight the points and say, I think I see a planet. And then that gets sent off to people who will then look and try to validate if what you said is true. Through this process, they found a whole bunch of stars that misbehaved. One of those stars that misbehaved is Boyajin's star. It was discovered by planethunters. It was discovered by citizen scientists like you. So we need you. Thank you. What they found was a light curve that looked like this. This is brightness relative to its normal brightness as a function of time. Time here is in a funny unit. Astronomers love using really bizarre units. This unit is basically units of days. The couple of mission lasted four years. You can see it's 1600 days. And you see some things that jump out at you, right? There are two big dimming events that happened on this star. One right in the middle and towards the end. Right when the mission was ending, it was dipping. We don't really know what those dips were, but let's zoom in and take a look at what they look at a little bit closer. There were a series of really small dips at the very beginning of the mission that were about 0.5% in brightness. So it's a very, very small change in brightness. That's about the change in brightness that you would expect from having a Neptune-sized planet transit this star. So if there weren't planets, they would be on the scale of those wiggles. We don't see anything that looks like planets here because they would have that nice flat bottom shape and go back up and they would repeat again and again once per year for that planet. We don't see that here. Then there's a big 15% dip halfway through the mission. At the end there's a 20% dip. Recall in your head that image that we had of the moon transiting the sun, Venus transiting the sun, those weren't blocking out 20% of the sun. So whatever this is, this thing's big. Okay, let's dig in. So I told you that bottom axis of time is in units that nobody understands. I'm going to translate them to dates that you do understand. March 4th, 2011 was the first really big dip. On that day, Tabby's star, Voyage & Star, wasn't the only thing dipping. I googled the headlines of what was happening that day and I found that on March 4th, 2011, Justin Bieber kicked his backup dancer in the throat. The lights went out for him too. You can see how bad he feels too. His glasses came off and he was like, but back to Tabby's star. The brightness dipped very abruptly by 15%. Broccoli is what here. Let's look at this, units of days, right? So this whole thing lasted maybe three dates. That's a long time frame. Most exoplanet transits only last a few hours. So this is days, that's interesting. Maybe in your head you might think, okay, so if you're further away from the star, you would forward it slower, maybe that would allow you to spend more time in front of the star. Okay, maybe. Let's think about that. One of the most difficult to explain features about this light curve is the fact that it slowly dips at first and then it abruptly rises in brightness at the end. We'll explain why that's tricky. When a planet transits a sun, any star, this is what you see. We get this nice flat bottom shape as the planet starts to block light from the star at one. You decrease in brightness until the planet is totally on the star at two. The brightness stays the same until the planet begins to leave the star and it goes back up. That shape is symmetric because the star is symmetric and the planet is symmetric, they're both circles. If they weren't circles, you'd get a different shape here. So we would expect symmetric events from transits and recall that's not what we see from Boyajan Star. So some people try to appeal to other objects in the solar system that you could use to explain what we see. One of those things could be a comet. It's a little bit difficult to see, but comets look something like this. They have what's called a nucleus, which is where the material is coming out from. They call it a chunk of ice and rock. And then they are giving off gas, which leaves the comet and forms a tail behind the comet. And so if you were looking at this in front of the sun, the center here would block most of the light and then out here it wouldn't block very much light. It gets thinner and thinner. And so what I'm trying to show in this diagram here is that it's blackest at the point of the triangle and then it fades out towards the other side. So what you would see instead of a normal exoplanet transit, which I've dotted here, you would get an abrupt dip in brightness at the beginning as the nucleus, the most dense part, passes in front of the star. And then once it's moving across the star, you move to successively thinner and thinner parts of the comet's tail and your brightness very gradually returns back to normal. That's an asymmetric event from an object we know in the solar system. But it's going the wrong way, right? A very slow dip with a quick rise. This is a quick dip with a slow rise. So that can't be it. It's almost like it's a backwards comet, right? So how do we explain that slow dip and a sharp rise? Well, we can move to less likely scenarios. Let's take a look at something else in the solar system. We have another object that's pretty cool. It's called Saturn. I love Saturn. If you look at Saturn, when it's in front of the Sun, from the Cassini spacecraft, which is in orbit around Saturn, you see this. This is Saturn eclipsing the Sun. Let's now imagine that we were observing this from very, very far away, like we might be for Voyage and Star. If you had the tilt of the rings just right and you put the planet just at the bottom of the star, the first thing to pass over the star would be the extended rings. And then that would lead to a gradual decrease in brightness because the rings get denser as you move towards the inside. And then once the planet starts blocking out light, you block out a lot more light, but then the whole thing leads the surface very abruptly. That could give you this kind of asymmetric thing. You got a slow dip and then a quick rise. So could it be Saturn? It's hard. We don't really know. In order to produce a few-day-long dip, you would need rings that are bigger than any planet could have. That's a bit tricky. Then the next dip occurred. I'm going to bring you back in two time here. February 24th, 2013. Does anyone remember what they were doing? How many of you watched the 85th Academy Awards with Seth McCarland? You might remember that someone did a dip. So did Voyage and Star. Here's the dip from Voyage and Star. The brightness decreased by 20% this time. We really loved it. And the powder is not as simple as the other one. The other one was asymmetric. Sure, but it was pretty well behaved. It looked like one thing could have been passing from the star. This time it's a mess. We've got a smooth dip and then a really sharp dip, and then it goes almost back up but not quite, and then it dips again, and this one looks maybe symmetric in the corner, but then not over there. What's going on? It goes back up and then it dips asymmetrically again. This one's a mess. If you have an idea for what can cause this shape and brightness, please come to me because no one else does. I'm waiting. But there are some really outlandish ideas that you can come up with to try to explain it. One of the ideas that's fun to think about is that we think the moon, our moon, formed when a Mars-sized planet hit the Earth. That impact sent a bunch of debris off of the newly combined object, which then formed the moon. But during that impact, maybe there was some debris that got shot outward and ahead of the planet in its orbit, which could give you the backwards comet shape of your distribution of gas and dust. So you have your planet here that collided with another one, and the high-speed secondary came in and smacked it and then shot material out in front of the planet. Maybe that's the only way that we can explain what happened. But that's pretty unlikely, right? That happened in the solar system one time. There was one moon forming impact here. And so what are the chances that we were looking during the four years when this happened on that one solar system? Maybe pretty low. It's getting harder. Then the current idea that's getting the most traction among people trying to figure out what this object is is that it could have been a family of comets. The idea here is that that first dip could have been maybe one big comet that then got broken up and then the second set of dips happened with the broken-up comet passed back in front of the star. That can explain why it's so asymmetric and strange in the second dip. That could explain how you block out so much light because now you have a ton of comets. But that's a little tricky too. I'm going to try to explain why. One reason why it might be plausible is because we've seen something like that happen in the solar system. There was a comet called Shoemaker-Levy-9 which was discovered as it was passing by Jupiter. During that pass by Jupiter, it was tightly disrupted. Jupiter's tides ripped it apart. What you see here is an image of this string of now many comets that were broken from an originally bigger comet that then went around the Sun and went back into Jupiter and hit it. It's a little difficult to see but there's an impact crater in the gas atmosphere of Jupiter there. Astronomers predicted that it was going to hit Jupiter and we're very excited when they observed it. It's difficult to see but there's a bunch of nerds partying here. One of them is Shoemaker, one of the people who, the one raising the champagne is Shoemaker. What we see here is an infrared image of Jupiter. It's brightest at the poles. That's the moon Io and over here this little flash is the impact happening. You're observing an impact on Jupiter. I expect that maybe there were ripped up bits of comets. The reason why I'm a little hesitant with this idea just goes back to your basic physics knowledge. We all know Occam's razor. We all know that we want the simplest explanation possible. However, Tyler, Tyler, and Matt, that food's all for me now. If you want to make a claim that something really rare was happening in the solar system that we're observing, something like a moon forming impact or comets breaking up, you need extraordinary evidence to make that claim. Those events are not things that happen frequently. Seeing one in the four years that we were looking feels awfully suspicious. Carl Sagan once said extraordinary claims require extraordinary evidence. We don't actually have the evidence yet to say that any of these things actually happened. Another way of putting it and one way that I like to think about the comment explanations that people are using is that the more bodies that you imagine being there, the easier it is to fit a light curve. If you just keep adding new parameters into your model, eventually it'll fit. Or Kelvin, who had a normal human name, William Johnson, once said with three parameters, I can fit an elephant. How many comets are people invoking when they try to make these comment models work? It's something like 10 comets, something like 20 comets that are all giving off mass at the highest possible rate in order to block out 20% of light. It starts feeling more and more unlikely. One way of illustrating that is over here. Can anybody in the back see this red curve? It's really difficult to see. You'll see something else get filled in in a moment. For those of you who can't see, there's a red curve here that looks like this. It's a weird asymmetric light curve that has bumps on one side and bumps on the other side. Can anyone tell me with their eyes what they think would cause that shape? An elephant. Well, you might have noticed the date here. Let's take a look at it. With a complicated enough model, you can fit any transit. This is a little facetious. This was provided for you by Joe Lama through the top of the voyagion. Thank you, Tabby, for that wonderful image. The point here, the serious point behind this is that if you invoke weirdly shaped objects, you can fit perfectly. If you invoke the kinds of objects that we expected most likely, it's a lot harder. We really don't know what this star is doing. To make matters worse, the star was not just dimming very abruptly the way that we were looking at it in those previous plots. We were dimming on long time scales. This shows the brightness as a function of time in those funny units again throughout the entire Kepler mission. You can see that it didn't by 3% late in the mission before the big 20% dip, and it was dimming by 1% in three years before that, almost linearly. Nobody predicted that that should happen for stars like this star. We don't understand what that is. So people started to wonder, could there be some intervening dust or gas, or any material that both us and Voyage and star are moving with respect to? And so this gas might be moving in tuned away and blocking out some of the starlight. Well, that could happen. Here's what a cloud of interstellar molecular cloud looks like. That's what we call these. This is not a hole in the universe. It is a dark cloud of gas and dust that's blocking light from stars. There is an even field of stars behind it. You just can't see through the cloud. You can't a little bit. You can sort of tell that the stars near the edge of the cloud are red. That's because dust lets red light better than it does let blue light through. So you can see that. If you look at the infrared, you can see a little bit more through the cloud. So as you go up to redder and redder wetlands, which are more permitted by the dust, you can see. This is where I enter the story. I'm going to inject myself into the story right here. The way astronomers today find out when stars are doing weird things is on Twitter. I encourage you to go on Twitter. Dr. Boyashin sent out a tweet saying it's dipping! Go observe! This was, as you can see, this was May 19th of this year. So Kepler was not looking at this star anymore, which means that if anybody was going to observe it, we had to take our own telescopes and stay up at night and go and look at the thing. And so I spent a few nights doing that. And I was rewarded by being retweeted by Dr. Boyashin. I saw a 100% increase in people who like alien talk. But I wanted to do what I wanted to look for was to see if any of the features of interstellar material were changing on this star over time. If you take a spectrum of a star, you get out some red to blue spectrum. It's not actually that clean, but you get a spectrum. And then if there's material between you and the star, it leaves absorption on the spectrum, which then we can go look at. Where the absorption happens at which color tells us something about what material is absorbing and where it is. And so what I was doing was I used this telescope, this is the Apache Point Observatory 3.5 meters telescope, to look at the star and see if we saw anything in between us and the star in absorption in the spectrum. What we see is this. The absorption feature of sodium, which is common in the universe, wherever there's gas and dust you'll find singly ionized sodium which produces this absorption band. If you've ever seen sodium street lights, the ones that glow a little bit orange, that orange glow is this wavelength. That's what you're looking at. And so now we're looking at brightness as a function of color, not time, different depth. And you can see three different nights in three different colors here. It's not changing, even though the brightness of the star was changing by 3% over these nights. So it doesn't seem like interstellar dust is causing this, which was one of the most attractive ways to explain the long, slow, time-scaled inning. So we're slowly ruling things out. It's not something in our solar system. It's not something between us and the star. It's got to be something near the star, but we don't know what near the star could be doing this. To try to answer that question, I'm working with a team of undergrads. One of them is here. Aislin, when you... Everyone say hi to Aislin. Aislin is observing right now. Aislin is using the 0.5-meter telescope in New Mexico from a laptop right there to look at the star and see if it's dipping tonight. And with the help of Steven Riley is not here. And so I want to leave by giving you the call to action to tell you that we really need all the ideas possible. This is one of the only stars to have its own subreddit. And there's a very, very lively discussion on Reddit about what this could be. There are plenty of people who have retired from engineering jobs who really want to figure this out. So if you're one of those people, please, please contribute. So I'm going to stop here to say you can keep up with what's going on on Twitter and all of the science is happening today. You can also play with the data yourself. I've made all of my data open source so you can go play with it and try to come up with your own theory. And I encourage you to go to planethunters.org to see if you can find not only new planets, because they have discovered planets that way, but also weird objects like this one that keep me up at bay. Thanks. Happy to take your questions. The question is how do we know there's not an issue with the spacecraft? The spacecraft was observing 150,000 stars at the same time. If we can look at all the other stars that it was looking at and see if they do similar things, that's one way. We can also then look at the data at a better resolution than we normally do. Most scientists deal with the catalytic data the way it's given to them, but some scientists go one step further and actually look at each individual pixel where nothing was misbehaving and looked to see that everything's working out. So they did that, and then they said, we still don't want to believe this. So they went to the NASA engineers who built the spacecraft and said, what could cause this? And they said, no idea. So they did everything they could to rule out every kind of instrumental systematic that could do that. And no other star does this. We have a lot of stars to look at. This is the only one that does it, so we're at a loss. Yes. Questions, where is the 3.5 meter telescope? It is in New Mexico. It's four hours from Albuquerque. You can see El Paso and White Sands New Mexico from the mountaintop. It's down ahead. How old is the star? Questions, how old is the star? That question is pretty much the bane of astronomy. Nobody knows how old anything is. And you can try really hard to figure out how old things are. And you can do pretty well on some stars. It turns out that F stars are particularly difficult. The reason for that is stars like the sun and smaller have conductive envelopes and they're trimming material near the surface. F stars don't. And so there isn't this exchange of material from deeper in the star and there aren't spots on the star. So you don't have that much to study when you look at the star. It's age. The best way to figure out what its age is would be to use astro seismology which is the coolest thing in the world. They're doing seismology on stars. They can do that because the whole star is ringing through pulsation modes that tell you something about the interior of the star just like we learned about the interior of the earth from seismic waves through the earth. They can do that on bright stars but unfortunately this star is a thousand light years away. It's not that bright. We don't have a good shot at getting those kinds of measurements. So it might be stuff not really knowing its age for a long time. Any questions? Over here. I'm going to sum up that question for you. The summary of that question is could it just be the star? Could the star be doing something weird that we didn't predict? Could it be the star? Not something blocking out the star but the star itself, right? And we've only been looking at stars for so long. If this is something that stars do once in a billion days then maybe this just happens to be our lucky day. That question also keeps people up at night. We know that stars have cycles. The sun has an 11 year activity cycle. This star isn't expected to have an activity cycle like that. We don't know of any cycle that should cause dimmings by 20%. That's really the hard part here. We can come up with ways to slowly change the brightness over time by adjusting some of the physics inside the star that we can't see. But making it dim by 20% for a few days is really tricky. So I think that's the biggest problem there. So it seems unlikely that you could explain those dips given the star being weird. But maybe the long term thing could be something that stars do. There have been a few propositions for ways that you could make the star do that. One is that the star could have eaten a planet. That is a pretty far out idea. If you then have this planet that's dissolving in the outer layers of the star that material is slowly settling into the star and you would see a slow change of brightness in the star. Again that's a pretty unlikely thing to observe so we don't want to say for sure that's what it is and also it's really hard to make models to predict what that would look like. So it's hard to say. We have a question from online. Why does such an old F star spin so fast? The question online for streaming. Next time you miss is starting to attack. You can get us online. Why is the star spinning so fast? Usually the rotation rate of the star is related to its age. The slower it spins the older it is. But the other methods for calibrating how old stars like this F star are are pretty tricky. So I'm not going to make any definitive comments about its age because we don't really know. What is the sun's rotation period? The sun's rotation period is 25 days. It's a lot slower. Are any of the slow dents the same each time? The answer is no. You can try really hard to overlap them and stretch them and work them and they just don't really line up. They're not all slow at the beginning and then fast at the end. But that one that we detected where it does that was an explicitly good measurement and we know that it was doing it in that time. Are there any legitimate astronomers that think it's a Dyson sphere? I'm not going to comment on the legitimacy of other astronomers but I'm going to say that extraordinary claims require extraordinary evidence and I do not have any evidence to suggest that we can make a claim as extraordinary as that just yet. Is it possible that the things that we've already moved out are the explanation and we just don't understand what we're looking at? I think it's kind of just your question. Absolutely. Scientists have no idea what we're doing. No idea. We're looking at the sky and hoping we figure it out but we have no idea what's going on with this star. So it's entirely possible that it's something like an interstellar dust cloud which I think I've rolled out which maybe 20 years from now it's absolutely what it is but as of right now given the data that we have there's no one good explanation. There's a bunch of bad explanations. Could there be a distant eccentric body maybe with a debris disk or some kind of disk around it that could be causing what we're seeing in the long-term dimming? It would be hard to make a long-term dimming like that from the third body that we haven't already seen because they used Keck one of the biggest telescopes in the world with adaptive optics which basically removes the atmosphere of the Earth to get really high resolution images of the star to see if there are other stars next to it that could be confusing us and it doesn't look like they're right. You could never say that with 100% certainty because there could be a star just next to it right behind it but as far as we can tell it looks like we're not being fooled by another star. The largest dimming that's ever been attributed to a planet in fractions of brightness let's have a minute, I don't know it would be of order 2 or 3% yeah, so 20% is huge planets don't do that if it were a planet it would have to be like 5 times the size of Jupiter and if you're 5 times the size of Jupiter it's not a planet, it's a star and we would see that star in our other observations we have non-visible light spectrum data we do, we've observed in the infrared, which is the most interesting in this context if there was a disc of material around the star that could cause some of this dimming let's imagine there's a disc of asteroids or something that was really dense that could cause this weird stochastic dimming that field of asteroids would be warm because it would be warmed by the starlight and warmth would radiate away in the infrared and so we looked at observations in the infrared at 3.5 and 4.2 the two Spitzer band passes that are still going and we don't see an excess of infrared radiation we see what we would normally expect for a lonely star with no disc and so our observations that other wavelengths seem to suggest it's a normal star do they dim the same? we don't know the answer to that unfortunately our observations in the mid infrared were not coincident with any of the dimmings we do have coincident observations in the near UV and we see that the dimming of about 3% happened over the 4 years the slow dimming is consistent with the dimming that we see in the optical in the near infrared it's about the same which means whatever is passing in front of the star to make it lose light is extremely gray in order to block out the same amount of light in the near UV and in the near infrared you need something that has no color that's peculiar could it just be a really dense star dead star all stars emit light so no we would see it in the spectrum and we don't the only thing that does it is a black hole that wouldn't block out light like this leave a different signature it is not periodic however we don't have an answer the difference in time between the dip in the middle of the data and the dip at the end of the data was about 750 days if you extrapolate forward 750 days after the end of the mission Dr. Voyage hadn't written the paper yet and nobody was looking at this star 750 days after that one is when the last dip occurred that's when the tweet came so it's possible some sort of periodic dipping on 750 days but we don't know if it's the same object and we would need to observe for more periods before we know for sure that that's the period Dyson Spear could it be due to relativity could something behind the star be fooling us it could it seems unlikely that something would be aligned just so so that we couldn't tell that it was there we wouldn't see it in the spectrum but it would change the brightness one out of 150,000 is better than your chances of winning a lot of them right so it would be very very strange to catch something that rare and then sample that small what does a black hole look like if it went in front of the star black holes do what that other gentleman was asking about they bend light from behind them so when the black hole goes behind the star you wouldn't notice anything but when it passes in front of the star it would lock out a tiny bit of light the light that would hit the black hole would fall into the black hole but it would bend a lot of light from around the star from around the black hole and magnify the brightness of the star you would see that signal as a net brightness of the star that looks just like a transit but upside down that hasn't been seen from a black hole but it's been seen for compact stars by this gentleman in the front road Ethan Kruse the period in between measurements that I'm showing you is 30 minutes a very high resolution in both precision of our brightness measurement and in time for other targets where we knew they had planets or they were doing something else that was interesting we upped it to once a minute so we have a bunch of targets that we could have driven really high cadence so if there were other things that were doing this we could have seen them happen at a better resolution we didn't catch them so I have one more question from the internet why did the star get brighter than normal before the dip? why did the star get brighter than normal before the dip? I don't know we have no idea