Short Wave - The Community Scientists Who Helped Discover A New Planet

Episode Date: March 30, 2022

When a team of exoplanetary treasure hunters joined forces with professional astronomers, they discovered a whole new world. Short Wave host Emily Kwong talks with astronomer Paul Dalba and community scientist Tom Jacobs about how their collaboration led to the recent observation of a new Jupiter-like exoplanet.See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Think back to your childhood. And you may remember that a lot of kids go through a science phase. For you, the fixation might have been rocks and gemstones. Mine was dinosaurs. Tom Jacobs, he was a celestial objects kind of kid. Well, when I was in third grade, I baked a comet. What?

I faked a comet. Tom grew up in Seattle. And the science fair came up, I thought, well, I'll just mold myself a comet, make it red like fire, and put sprinkles on it, and I baked it. Can you imagine that in or end for the science fair? Was it delicious? Did you eat it? Oh, no. No, I didn't eat it. But Tom did get bit by the astronomy bug. And so did Paul Delba. For him, it happened when he was 10 years old, growing up in St. Louis, Missouri. I remember getting a small little celestial on telescope and then dragging my dad out of bed at about five in the morning to go use it the next day. And the very first thing

we looked at with the telescope was Jupiter. And the rest is history. Paul is an astronomy and astrophysics postdoctoral fellow of the National Science Foundation. He scans the skies with telescopes for a living now, searching for planets beyond our solar system. which are called exoplanets. The field of exoplanetary science is sort of in a gold rush era, where we're trying to discover as many of the exoplanets that are out there. We're trying to determine what kind of stars have planets, what are the properties of those planets,

and how did they come to be? Now, to find an exoplanet, or a planet beyond our solar system, takes a lot of work. Astronomers, like Paul, will look at datasets and use this methodology where they try to, identify something called a transit event. Imagine you're looking at a star and a planet begins to cross in front of the face of that star from your point of view as that planet is orbiting its star. The star will become a little less bright.

Because the light from the star is being blocked by the planet? That's right. Yep. And then once the planet is no longer blocking the star, the star goes back to its regular brightness. We look for those periodic exoplanet transits as sort of the signature that, hey, there's a planet orbiting that star that we can see. I picture it almost like a planet winking at you. This is almost like a planet saying, wink, I'm here, wink, can you see me? Did you look? These moments show up in the data as a light curve, which is just a graph showing how the brightness of a star changes as a planet passes in front of it. But when the data sets are massive, like the ones coming from the NASA satellite tests, the transiting exoplanet survey satellite,

astronomers have to rely on fancy computer codes to pick up obvious patterns. Usually these are multi-transit events, meaning many instances of a planet passing in front of a star. But what about those planets that, from our perspective on Earth, are a bit more subtle, meaning harder to find, because sometimes our telescopes only catch the transits once. Those are called single transit events. Paul says spotting them in the data is a bit of a bit of. big challenge. So I found myself with this problem of how am I going to look through thousands, tens of thousands, upward towards millions of these light curves to find these events that I want.

Enter Tom Jacobs, former Comet Pastry Chef and Navy Officer turned Planet Seeker. Tom is what's known as a community scientist, a member of the public who is passionate about gathering data and participating in research projects. And he's one of seven community scientists who call themselves the visual survey group. Think of them like beachcom. finding the good stuff that other scanners of the sand might miss. A visual surveyor is actually a treasure hunter. So in this case, you see some treasure, and it's like right there in front of you, and you get excited thinking, oh, this, it looks like a planet.

Today on the show, what happens when an exoplanetary treasure hunter crosses paths with an astronomer? And together, discover a whole new world. And we'll talk about the role that community scientists have to play in expanding our understanding of the universe. I'm Emily Kwong, and you're listening to Shortwave, the Daily Science Podcast from NPR. Tom Jacobs and his visual survey group, by the way, are not new to this work. We're on probably over 67 peer-reviewed science papers. We have found a lot of planets and a lot of other interesting objects. But that didn't make.

their discovery of a Jupiter-like exoplanet, T-O-I-280B, any less thrilling. Here's how it all went down. So Tom's usual routine for planet hunting is to sit down in front of his computer in his den and fire up this software called LC-Tools. He downloads data from Tess, that satellite scanning for exoplanet transits, and he starts scrolling. As you're scrolling and these light curves are flashing in front of your eyes at one to seconds, that pretty much takes your attention. You're pretty much

focused on that. He's scrolling and scrolling and scrolling. When on February 1st, 2020, something stopped Tom in his tracks. This beautiful light curve came across the screen and it had all the ear markings of what a planet

looks like. And this is how Tom and Paul met. Tom and his team of community scientists had spotted something huge. A single transit of One of these rare moments where we catch a planet transiting once. Word traveled via Tom's fellow community scientist, Daryl LeCource, to Paul Dalba, who we heard from earlier. He's working as a professional astronomer based at UC Riverside and UC Santa Cruz.

So I wake up to an email one morning from Daryl LeCource with the term, seems too good to be true. And I thought it was, too. It was the light curve of this exoplanet was just that pristine. but indeed it was true. I've read that about 5,000 exoplanets have been confirmed, like discovered. But there are thought to be billions in our galaxy, which is incredible. And I know that planets are typically found in a multi-transit event situation using computer algorithms and data from the ground or from a telescope like tests.

But this planet was found through a single transit event, one moment in all that data. like the single Waldo on the page. And Tom, you found it, right? That's right. And so the way this works is that as we're looking at the light curves, we look for shallow dipping events. And I'll tell you, TOI-21AB just shouted out. I mean, there was just no doubt in anybody's mind

that this was something worth pursuing. And this light curve, this kind of visual snapshot of a planet passing a... star. I saw a copy of it, and it was kind of beautiful. It was this scatterplot of light with this clear dip in brightness that went back up again. It just had this noticeable pattern. Yeah. Each type of object, celestial object, has a pattern. A exoplanet has a U-shaped pattern shallow. Then we have really curious-looking objects like exocomots that looks like a shark tooth. These patterns show up and you learn over time what the patterns look like.

This is serious manual labor. And it's labor, it just strikes me because it's work that you're saying, Paul, an algorithm can't really do. Yeah, I want to emphasize just how challenging it is to do what Tom and the visual survey group do. The data that comes down from tests, these light curves, the brightness measurements is a function of time, they're not always clean. oftentimes if you don't just see the steady brightness from the star, the spacecraft has slight wobble motion. You know, it doesn't sit perfectly still in space, and that can introduce noise and what we call artifacts to this data,

and they can mimic the signals of exoplanet transits, or they can just introduce a bunch of weird behavior in the data that might cover up a transit. And so you're sort of in a perilous field here, searching for real exoplanets and trying not to get tripped, up by the things that are just systematic errors. It's hard to do. Yeah, Tom, prior to this, you were in the Navy, right?

I was in the Navy. I was a former naval officer. I was in nine years. That's ancient history, though. I mean, do you use any similar parts of your brain for this work? Because out in the ocean, you have to be able to recognize patterns, too. I remember being on the bridge of a ship when I was first in the Navy. I can just remember the captain Bellering, Mr. Jacobs, put your head on a swivel, you know, because you had to be looking all around.

And so, yeah, I think some of that does kind of ingrained forever in your brain. So this exoplanet that you found, if you could paint a picture of what we know, what would you say about T-O-I-21A-B? and what are some unique things about it? I would describe it as a super Jupiter planet. Super Jupiter, okay. It's about the size of Jupiter, but it's almost three times more massive. The system itself, the star system, is relatively close to Earth. It's about 379 light years away from the Earth.

And that makes the star brighter, and a brighter star is always good, because more light means more information, means we can do more with the system. So that's sort of the first thing. The second thing is that this planet does indeed transit. And then the third piece of this trifecta that's really special is that the length of the year on T.O.I. 2180B is about 261 days. That's more than 10 times longer most known exoplanets that transit their host stars. And so the fact that the system is close, it transits its host star, but it also has this long orbital period. Those three things put together are exceptionally rare for a gas giant planet.

There are plenty of planets that have one or two of those, but the trifecta is rare. And that makes this a really amazing planet to get a full picture of how it formed, what it looks like, what its atmosphere might be made of, and it'll tell us a lot about giant planets as an astrophysical class of objects. And what's super amazing, too, is that this whole planet was discovered through community science. And I want to ask you, like, what happens when science makes space for community scientists to be a part of it? It's synergy at its best. There's no doubt about it when you have the amateurs working with the professionals and the amateurs are going through large amounts of data, saves time. It does all kinds of wonderful things when it comes to science.

There's no doubt about it. I hope that with community science, what is being done is the removal of barriers that keeps some people from being able to contribute to scientific endeavors in making science accessible and something reachable by anyone who has an internet connection I hope to just improve the climate of the entire field of astronomy and physics and any STEM field in general and I just hope to improve awareness and understanding of the scientific process and what we do because that's going to

be important in many facets of our lives going forward and the more of our population that can get behind the science we do by contributing to it and being part of science. I think the more of that, the better. Absolutely. Yeah. And meanwhile, there is so much still to learn about this planet you discovered, T-O-I-280B, this pretty big, pretty close, gassy boy, detected through a single transit events, but you are waiting for further confirmation from another data set, right? Well, we're going to pop the champagne corks if we find the second transit of TOI-21 ADB. I think the most important thing is we want to see a transit again. Absolutely.

Yeah, and we think it's going to come out in this next data set, which is coming up. Just days after we spoke, we got an update from Tom and Paul. The test spacecraft had detected a second transit of TOI-2180B. I'm opening up the light curve, and there is TOI 2180B, the return, and it's a beautiful light curve. And so I'm totally excited. As of today, I received an email from Tom Jacobs and the other community scientists in the Visual Survey group. And finally, the title of the email was Return of the King. Observing this second transit means the team studying TOI-2180B can use telescopes in space and on the ground to observe future transits of the planet.

They can learn about its atmosphere, do novel searches for its rings or exo moons, and hopefully deepen this partnership with community scientist groups to keep discovering all that is out there. This episode was produced by Chloe Weiner and Catherine Seifer, who also fact-checked. pitched and source this episode. It was edited by Stephanie O'Neill, Gilly Moon was the engineer. Giselle Grayson is our senior supervising editor. Neil Carruth is our senior director of on-demand news programming, and Anya Grunman is our senior vice president of programming. I'm Emily Kwong.

Thank you for listening to Shortwave, and we'll see you tomorrow.