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Hank and Tabetha discuss the mysterious star KIC 8462852 and what might explain its odd behavior (It's probably not an alien megastructure).

Hosted by: Hank Green
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 (00:00) to (02:00)

(Intro plays)

Hank: Hello, and welcome to the SciShow Interview Show, where we talk to interesting people about interesting stuff remotely through Skype.  I'm in Missoula and Tabetha Boyajian, did I say that right?  

Tabetha: Boyajian.

H: Boyajian, you are in Louisiana, former researcher at Yale University, currently at LSU and you've been working on maybe one of the weirdest things that has happened in astronomy research in a long time.  Tell us about this weird thing.  

T: I work on the science team as part of the Planet Hunters citizen science project, which is a part of (?~0:51) collaboration, and what Planet Hunters does, it's an interface that shows data from NASA's Kepler mission to the public, and so, you know, people can sign on and look for what we call transits in this data.  We cover telescope measures as far as brightness vs time and when a planet crosses in front of a star, then it blocks out a tiny bit of light, and you can see this in this data, and this is what the Planet Hunter researchers, the citizen scientists, are looking for, and the thing is like, when you're going through all this data, you're looking at every single star and you know, what every single star does, and stars can do lots of things.  They can pulsate, they can have flairs, they can have spots, they can be a binary star, many, many different phenomenon.  But they came across this one star that didn't really like, fit into any classification that, you know, they had seen before when they started talking about it and discussing it amongst themselves.  They get to the point where they got something off to, you know, reach out to the scientists and say, hey, what's this?  

H: Yeah, when--we're looking at Kepler data, usually we're running, I assume, because it's so many stars and the vast majority of them are nothing really of particular interest is going on, so I assume that we have computer programs that are trying to find specific patterns and they're pulling those out and then later for direct analysis by scientists. 

 (02:00) to (04:00)

But if it's not fitting that particular pattern, it's not necessarily getting pulled out by those programs and thus not even getting looked at, so is this citizen science group, is it the goal is to try and find some things that might not be noticed by computer programs?

T: Um, well, I mean, you're right about that, computers do exactly what you tell them to do, and you know, especially with time series data as simple as this, you would think that, you know, like, the computer would be able to pull out, you know, something as periodic as a planet in orbit transitting around a star, and so that was kind of a gamble when we set up the Planet Hunters project is that it was designed to look for transits which computer programs were looking for the exact same thing.

H: Right.

T: But, you know, we've actually found dozens and dozens that have been missed by the computer programs and this has been able to inform the algorithms on, you know, where they have, like, you know, leaks in the pipelines and so they can patch those up so that it can be more and more efficient, but you know, again, as you said, like, I mean, you can also see, since you're, you know, people are viewing these data with their eyes, you know, they can spot out something that you weren't actually looking for in the first place.

H: Yeah, so you guys noticed a particularly--or somebody at Planet Hunters noticed a particularly weird looking signal and that became a pretty big story.  What is this star and what did it look like?  

T: Well, the Kepler data lasts for four years, and it took a brightness measurement of a star over 30 minutes, and what we see for most of the time, the star's light or it's light curve is flat, meaning it's not really doing much of anything.  

 (04:00) to (06:00)

But then it's punctuated at about a dozen places or so in these drops in its brightness, these dips, and these dips are, one, they're unusual for this type of star, they are not periodic, they're, you know, they're not symmetric, they last for the longest amounts of time and then go away for, you know, years, and there's really nothing that says, okay, well, this can be, you know, associated with this phenomenon or this can be, you know, associated with that phenomenon.  Yeah, and they're insanely deep as well.

H: Right.

T: Like, these dips went down, like, some of them were only, you know, a percent or a fraction of a percent deep and some were over like, 20% deep.

H: Oh wow.  I mean, is that--so is that--

T: And so none of them looked like any of the other ones as well.  

H: So, like, are there sometimes planets that big that transit or that close that transit?  I guess like a supermassive like, hot Jupiter might create that kind of a dip.

T: So, for this type of star, it's about 50% bigger than our Sun, so a Jupiter, which it's theoretically as big as planets can get, if you put more mass into a Jupiter--

H: Right.

T: Then it will stay the same size.

H: Mm, okay.

T: And so if Jupiter was, you know, transiting this star, it's--it would take over 50 Jupiters to make 20% drop in its light.

H: Okay.  So basically what we're saying is like, no one knows at all what's happening and thus let's start just speculation excitedly.

T: Well, it didn't quite go like that.  You know, at first, at first, I mean, this is scientific (?~5:47), you know, like, you have a problem, you know, presented to you and then you started collecting data to see if you know, anything will lead to, you know, an obvious conclusion or something like that.  So we started learning as much about the star as we could, but everything that we learned about the star made it look normal.  

 (06:00) to (08:00)

H: Right.

T: So, and that made it even more difficult to explain what was happening in the upper (?~6:11).  And so honestly, for 
years, I mean, this was kind of, you know, being passed back and forth, you know, talking to dozens and dozens and dozens of astronomers, bouncing ideas off them, trying to, you know, see, you know, what's, you know, what we could test next, you know, what theory we could test.  All sorts of things were going on, and you know, honestly, there was nothing really, you know, in our eyes, it was nothing really exciting about this at this time, because we couldn't figure it out.  

H: I mean, not knowing is always exciting.  

T: Uh, yes and no.  I mean, now that (?~6:48) back on it, like, I mean, I had two different feelings on it, like, being, you know, not knowing, I mean, that's why we love doing science, you know.  As a scientist, we get to say something new for the first time, but it's, you know, at what point we are dissatisfied with 'Yay, I said something new, I accomplished this, you know, project, I answered this question, tested this theory out, and I have an answer', but this one it was, you know, years into it and it was kinda like, uh, well, we really don't know.  In that sense, it was frustrating, but then it was exciting, because wow, we don't know, so that's kinda cool too.  

H: Right, and well, part of the frustration, I mean, for me, is that if you look at the data from this thing, it's in the middle of like, this tremendous very long period of time of the signal being dimmed that Kepler turns off.  

T: Yeah.

H: And I was like, oh, great, perfect timing.  Could we just have fixed something to keep that going, 'cause like, it does feel like, you know, the thing you need more than anything else is more data, and I know that you, you know, this started as a citizen science project and to get more data, you know, that requires more funding, and I--it's interesting to me that you went for what I would consider a non-traditional route for finding that funding.

 (08:00) to (10:00)

What--tell me about that.

T: Well, essentially what we did is we did a crowdfunding project through Kickstarter to raise money to get more data on this star.  What this star needs is long-term monitoring.  Just watching it, you know, every hour for the next ten years, basically, and you know, it's a kind of high risk, high reward type project and this isn't really viewed favorably in say, the traditional funding routes as you know, something that's, I mean, when you have a grant--a successful grant, you know, it's typically something that's like, it's going to produce results, and this was something that was a little more risky and so that didn't really seem to suit us, you know, in any kind of public facilities that you can apply through, through NASA, don't actually have the capabilities to do long-term monitoring, and so we actually had to go to a private observatory that does have the capabilities, the La Cumbres Observatory is an array of telescopes, like, around the world, and this can monitor a star continuously, so when it's nighttime in the US, it's daytime in, you know, halfway around the world, and the Kickstarter idea came up quite naturally, because you know, this star was discovered by citizen scientists.  We thought we could continue on this theme and have people still contribute.  A lot of people were interested in what was going on and just, you know, we could educate them as, you know, to see, you know, how science is kind of in action.

H: So, so we can actually, I mean, I imagine that it is not easy to sensitively measure the brightness of the star from Earth.  I know that we can do it, but like, to do it for the potential years that we need to get good data on this, 'cause there, you know, you know, a large portion of Kepler's mission passed where there was just completely steady light coming from this star--is that a--is that feasible?

 (10:00) to (12:00)

Is that happening?  Is that--like, are we, are we, we gonna see it?  

T: Kepler was designed to catch transiting planets so Earth-like planets transiting a sun, and so Earth is 11 times smaller than Jupiter, and so like, you would see, like, I mean, it is such a fraction of a percent of light that it would take away from it, so there is, you know, the analogy that, you know, you have the Empire State Building and it's all lit up with lights and you have somebody raise one of the blinds down by one inch and this is the flux (?~11:05) that Kepler was designed to detect.

H: Right.

T: The signals that we're seeing at our star aren't that small, and so we can actually--we don't need that kind of precision that Kepler gave us.

H: Right.

T: Kepler did have year-round coverage, and there's a period of about 2-3 months in the wintertime when we cannot monitor this star, but you can't have everything.  But, you know, the precision that we do get from the ground is definitely enough to be able to catch it when it's dipping again and it's actually, I wouldn't say that it's better than Kepler, but we can actually tailor it to do what we want for this--the science on this star, meaning that when the observation is taken, it can be analyzed immediately, and we can tell whether or not it's in a dip event, because when it's in a dip, we can actually like, that's where we can get the information about what's going on, what's passing in front of it, we know what these dips will look like, how deep they'll be, you know, if they're gonna be periodic, you know, anything like that.  

 (12:00) to (14:00)

With data, with the Kepler telescope, data was collected and every three months, it would point back to Earth and download the data, and so we won't know until afterwards, until one of these dips were happening, and so the fact that we can get this data in real-time from this network, it means that, you know, once we see it start dipping again, we could queue up larger observatories and telescopes and--

H: Right.

T: --get the more detailed data and figure out what's going on.  

H: So like, if there is--if there is something (?~12:39) star's light, that thing is very large.  You would think that it would get hot and thus it might radiate its own radiation.  Could we learn something about the object or the objects that are (?~12:50) the star from the radiation that they themselves emit?

T: Exactly, so this was actually the biggest thing that--it gave us the most trouble with this (?~13:00) is that if you have any sort of surrounding dust mass or anything like that around the star, the light would heat the dust and (?~13:08) in the infrared and then (?~13:10) as an excess, and we did not detect this in any of our observations.  And so our way around it was, you know, the theory that, you know, we proposed that (?~13:21) natural scenario for now is that there is a sort of comet that's passing in front of the star, and this kind of gets around the whole infrared (?~13:30) because we would only have the (?~13:32) when the material was close to the star and comets (?~13:37) eccentric orbits and so you would have like, your central star here and the comets are like this, so it's a very short amount of time that it's blocking the light of the star, and that's where we have the (?~13:47) so most of the time, you're getting the, you know, observations are out here (?~13:49) too far away to actually, you know, have an infrared (?~13:54), and so getting a, you know, observations at all types of wavelengths will tell you, like, when it's dipping, will tell you, you know, exactly what's going on, what the material is made out of. 

 (14:00) to (16:00)

H: Okay.  So, I mean, for me, obviously, the most likely explanation is always just some natural phenomena we've never seen before.  I--is that where you would lay your money, and I know that we don't lay our money in science, but is that where you'd lay your money?

T: Yeah, I mean, I'm pretty sure everybody's like, on the same page.  You know, nature's a lot more creative than we are, and it's, you know, it's a matter of time.  With this, you know, we need more data to say anything more about it.

H: Yeah.

T: What would be even more awesome is if we found another one similar to this, 'cause that would make it easier to study because we would have, you know, a larger sample than just one.  

H: Do you know how many Kepler stars there are, like, and this is sort of the only one we found like this?  

T: Yeah, well, once we have the signal, we're able to go back through the entire Kepler data set of over 150,000 stars and search for just like, the basic parameters that we're looking for, and we're able to do this down to a certain level where we're gonna say confidently like, there's nothing down to, you know, (?~15:13) dips down to 20%?

H: Yeah.

T: We're able to make that cut at 10% and then at 5%, you know, below that, there's just way too many other things that stars do.

H: Right.

T: That get flagged in the pipeline.  But Kepler only looked at a very small portion of the sky.

H: Sure.  

T: Less than, you know, a fraction of a percent.  Like as big as your hand is held out in front of you.

H: Yeah.

T: Like your fist, and so we only looked at that part of the sky, and so, you know, new surveys coming out that are looking at millions of stars are going to, you know, hopefully give us a, you know, a new one of these, hopefully.

H: But I mean, one in 150,000 is still weird.  It's a weird star.

T: It is definitely a weird star, yes.

H: And then the--of course, the other--the other sort of--the headlines were all about maybe an alien civilization built some kind of, you know, partial Dyson sphere to collect the energy of the Sun.

 (16:00) to (18:00)

Are there any other super weird explanations that you've heard of?

T: Um, I mean, they all pretty much go down that--that avenue.  I do get a lot of e-mails from people that pretty much--yeah.  A handful daily, it used to be a whole lot more.

H: Oof.

T: But you know, sharing ideas and thoughts, and some are pretty far out there, I read 'em all, there's no--there's no way to reply to all of them, I'm sorry.

H: Yeah.

T: But they are all read.  So the problem with the Dyson sphere idea, though, is that, so you have some, you know, very advanced civilization that's, you know, building some sort of something to collect energy, right, anything that uses energy puts off waste heat, and you see this is in the infrared, and we do not see this in our observations that--that's what gave, you know, all the natural scenarios that are, you know, (?~17:11) for us to explain this star and so the fact that, you know, the Dyson sphere scenario also requires some you know, infrared excess, and we don't observe that.  It means that it's also not a very good one, among other reasons why it's not a good one.

H: Right.  Same goes for the potential that there is a giant interstellar space battle happening in front of the star.  That would be creating lots of blown-up ships that could be--that could--all the ship debris, all those giant ships that have been destroyed, also probably would put off some heat, I would think.

T: Yeah, I mean, this is like, you know, the material actually that's surrounding this star, you know, all the shrapnel and stuff like that, that's--the light would shine off of that and would radiate the infrared, but if you think about it, if you look at the Kepler data and this is just fun to think about, I'm not saying it's anything right, but there are two very big dipping regions that are separated by about two meters.

 (18:00) to (20:00)

If you assume that that's the same thing and it was some sort of, you know, catastrophic like, you know, explosion, interplanetary space battle, however you wanna put it, and that's the same material that's going around in orbit, then that will put the--whatever it was that got blown up in what we call the habitable zone of this star.  I mean, it's just a coincidence, you know, but it's like, you know, it's something interesting to think about for the, you know, for the sci-fi folks out there.

H: Yeah.  

T: But, you know, that being said, you know, the two dipping regions that, you know, I pointed out, that are very big, they look nothing like each other.

H: Right.

T: And so there's no reason for us to associate the two with each other, only that they're both really big.  

H: Yeah.  Well, I can't wait until 20 years from now when we have--when we have all the data we want on this thing.

T: I hope that it--something exciting happens sooner than that.  

H: Yeah, I'm--I'm--I'm being conservative in my estimates, because I don't wanna be disappointed.  I mean, so, like, what are your timelines for having more good data, and when you see a dipping event, what is the--what's your next procedure?  What do you do when you see that this--something is happening to this star, do you just call up all your astronomer friends and say, hey, I want you to point your telescope at this spot in the sky right now, it's very important?

T: Pretty much, yeah.  The (?~19:39) observatory, they're--we're working with them to set up a trigger system, and so we have--we're taking data right now, and we're using this data to find, you know, a sort of standard deviation would be, a decent limit to say, okay, once it goes below this level, you know, this is when we need to trigger a higher cadence on observations and we could also trigger spectral observations on their network, and there will get notified to, you know, to send out an alert to, you know, the bigger observatories to get, you know, infrared data, say, or you know, (?~20:15), like, you know, things to tell other things about the star.

 (20:00) to (22:00)

And so the timeline is, we're observing it now.  This Kickstarter was successful and thanks to like, over 1700 backers, like, we're able to observe it at least for another year and you know, after that, still working on a plan.  Perhaps we'll do this again with, you know, maybe another twist, but you know, we don't know when it's gonna be something again.  That's like...yeah.  So when we'll get results and if it does something again, there is no guarantee that we'll be able to interpret it either.

H: Right.  Of course.

T: And so this, you know, it's--it is what it is, but you know, that would give us that much more data that we can learn from.  If I go back to the two dipping regions I mentioned before, they're about two years apart, the next, you know, two year increment will be this spring.

H: Oh, okay.

T: And so, if there were a period to that, and I'm not saying there is, because they look nothing alike, but that would be, you know, a time to, you know, really cross your fingers and hope that it's not gonna rain globally.  

H: So, my last question here for you, I think is just why would it--I--it is very confusing to me that this would be difficult research to fund, because it got press, it's very weird, and like, it, you know, you say high risk, high reward, I'm not sure what the risk is except that we found out, uh, potentially, I guess, that--well, I mean, even, you know, we're pretty sure that--we're certain that it wasn't a sensor problem with Kepler or anything like that.  There is something strange happening here, it seems like it would be something that a university would love to throw money at.  

 (22:00) to (24:00)

T: Yeah, well, it's--funding rates these days are about 10% and so, I mean, I've been on, you know, interview committees and whatnot, and first of all, you have to have a funding call, like, through NASA.  They have to have a specific kind of channel that you apply through, and there is no, you know, weird alien megastructure star channel and if you don't fit into, you know, one of their channels or categories then you're not--then you can't apply.  But, you know, I've been on these review panels and if you're not like, with a funding rate of 10%, I mean, you pretty much have to have, you know, a project with guaranteed results.

H: Right.  

T: And this, you cannot, you know, promise anything in, you know, the typical three year timeline, because, you know, what if there's, you know, nothing exciting that happens in that timeline?

H: Yeah.

T: Yeah, it's just not designed for that type of thing.  Which is unfortunate, and you know, it's, you know, hopefully, you know, someday like we'll be able to have some sort of, you know, special channel for this kind of like, high risk thing through the government.  It seems that would be--you know, 'cause that's--when you take these risks, that's when you like, you know, really get ahead of yourself and--not get ahead of yourself, but when you start to, you know, really make a difference in learning new things.

H: Yeah.

T: And so, there should be something out there.  Just gotta talk to the right people to implement it but.

H: Well, thank you very much for spending time with us, but mostly for being dedicated to this weird thing, for finding a way around the, you know, around the systems of research funding to figure out how to continue studying it so that we can hopefully have a very cool new story to cover here on SciShow in the next few years.  

 (24:00) to (25:40)

I think it's fantastic and really fascinating and thanks for being a champion of this stuff.

T: Oh, thank you for being, you know, being here for it and you know, keeping it real (?~24:14) which is absolutely excellent, because there was some big hype.

H: Yeah.  Keep trying to find out what the heck is going on, because it's--I cannot wrap my head around what it might possibly be, though obviously I don't know anything as much as you do.

T: I bet it's gonna be a non-astronomer that figures it out.

H: Yeah?  Alright.

T: Yeah, because, you know, that's--I think there's a problem there is that I have this bias that I know too much.  You know, it's definitely a very likely scenario that, you know, because I say, oh, well, stars can't do that, right?

H: Yeah, yeah.

T: And then you know, we find this star.  My first reaction when I saw this star was like, it's bad data, stars don't look like that.  

H: Yeah.

T: And, you know, I wouldn't have given it a second look if it wasn't for you know, our citizen scientists who, you know, can do some, you know, preliminary checks on, you know, whether or not the data's good.  They said, oh, we checked this out, you know, you--this is real, you should have a look, and so--

H: That is very cool.  It's very cool and I guess that's why you gotta keep reading those e-mails.  

T: Yep.  I'm doing it.

H: Alright, well, thank you very much, Tabetha, for joining us and for doing really cool science.  It's a pleasure to have you.

T: Thank you, Hank.