Transcript: Dark Skies

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Fraser: Astronomy Cast Episode 153 for Monday August 31, 2009: Dark Skies. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos, where we help you understand not only what we know, but how we know what we know. My name is Fraser Cain, I'm the publisher of Universe Today, and with me is Dr. Pamela Gay, a professor at Southern Illinois University Edwardsville. Hey Pamela.

Pamela: Hey Fraser, how's it going?

Fraser: Good. So, this is… once again we're still catching up from the past, but this is Episode 153, and then next Episode 154 is going to be the live show that you did at DragonCon with…

Pamela: Yay!! Seth Shostak.

Fraser: With a few friends, yep. Which, if we put it up on the date, it would be Sept. 7, so it should all work out perfectly. And later on, no one will ever be able to tell our terrible lies… Alright, so if you live in a city, it's possible that you've never seen the Milky Way with your own eyes. So, to really appreciate everything that night skies have to offer, you've got to get out of the city, away from the lights, where the skies are really dark. But those places are getting harder and harder to find. So, let's talk about what you can do to find some dark skies, to fight to make the skies darker, and how to make the most of wherever you live. But first, Pamela, I think we should make everyone drool, can we hear a really cool dark sky story?

Pamela: Oh, for me it was the first time I went observing out at McDonald Observatory. I drove and drove and drove and drove and drove and drove during daylight to get out there because I had homework due, and I couldn't leave for the observatory until
I finished my homework. I get out there and I'm exhausted, and I'm supposed to spend the entire night awake with a wonderful observer Dr. Phil McQueen learning how to use the 30-inch at McDonald Observatory. And he's like… look, just make it until 5 in the morning, just make it until 5 in the morning. I didn't know what was special about 5 in the morning, and I'm pretty much melted into the desk beside the control panel computer when he nudges me and tells me to go outside. I walk out the door… now the thing about McDonald Observatory is the 30-inch telescope isn't on the top of the mountain, it's actually on a ring road that's a little ways down the side of the mountain, so when you step outside you have mountains straight to your left, and then looming over you are the giant domes of the 82-inch telescope and the 107-inch telescope. Then off to your right is just the desert plains of west Texas. I step outside and off to my right in the distance are all along the horizon–Texas thunderstorms… amazing amounts of lightning, and it's reflecting off the domes that are up the mountain from me. And straight in front of me is comet Hyakutake, which is just fun to say… but it's huge! It's taking up a serious amount of the sky in front of me, filling my field of view as though it's completely hanging on top of the dormitories at the top of the mountain, filling that entire section of the sky… just coming up, or just setting as the case actually was. Then straight overhead from me was the Milky Way like someone had poured it there, and I'd never seen the Milky Way that clearly. I'd seen really dark skies before, but not when the Milky Way was up. It was the type of thing that if you set it up in a planetarium show… lightning going off to the right, straight in front of you–giant comet filling large part of the sky, and straight overhead–Milky Way… no one would believe this planetarium show. But, that's what I actually saw. I was wide awake all of a sudden, and I made it to sunrise. It was just the most amazing… oh, wow, the sky does this? That summer comet Hyakutake was my best friend because every time I drove out to the observatory it was literally filling my windshield the entire trip if I turned my headlights down.

Fraser: Wow. So, for me, well I grew up on a small island off the west coast of Vancouver Island and pretty far away from civilization, so, in fact, we had really dark skies all the time. But actually just a couple of years ago I took my… my kids and I go back every summer to watch the Perseids. So we stayed up… they did the best they could… stayed up to about 10 o'clock watching the Perseids. We were all sleeping outside, so we just fell asleep. I think I woke up about 2 in the morning, 3 in the morning, and that's when you see the real show. So then it was just meteors, and the Milky Way was high overhead and just so vivid, so clear… it's just amazing. So, if you go out and you think you're seeing dark skies at like 11 o'clock, it's nothing to what you see at like 2… 2 or 3 in the morning. And for all you poor suckers living in the cities….

Pamela: And I was one of those suckers for a lot of years… so I know your pain.

Fraser: Yeah, so what's going on then… why is the view from the city so bad?

Pamela: Well, we're dealing with two different problems. The biggest problem is that our atmosphere is pretty good at reflecting light, and if the light it's reflecting down… the light that's scattering in the atmosphere is greater than the amount of light coming down from the star… you're never going to see the star. In cities, in rural areas with people with paranoid lighting schemes, there's huge amounts of light that's getting directed straight into the sky. When you go to archaeological sites, architecture sites, places with pretty buildings where all the buildings are illuminated, all of that light that isn't landing directly on the building–it's going straight up into the sky. And all of this light in our atmosphere on a cloudy night, it makes the clouds glow red, glow orange, glow white if you're someplace with a lot of fluorescents, and all of that is skyward-directed light. If you actually go someplace dark–this really confused me the first time I saw it–the places on the sky that are darkest… that's where the clouds are. I'm used to being from a city or suburbs with lots of light… you look up and oh, that bright orange thing is a cloud. No, in a dark site, the darkest places on the sky are the clouds. And in a truly dark site, the starlight is bright enough to read by, and a cloudy night is so dark you can't walk.

Fraser: It's interesting that you're in the city and you can have like… even in a place with no streetlights, there's still enough reflected light coming off of the clouds that everything is always sort of illuminated. And you don't really appreciate how dark things can get until you are out in the wilderness or away from the lights, and now suddenly you just have the starlight and it is dark!

Pamela: Right, nothing's quite as dark as a cloudy, cloudy night in a dark sky. And nothing's quite as bright as a cloudy, cloudy night in a light-polluted city.

Fraser: So you've got the illumination from the city being sent upward, and then it's bouncing off either clouds, or even just the atmosphere itself.

Pamela: Yeah. The other one… well, our own eyes have to dark-adapt. If you're inside in a bright kitchen, for instance…. you have a farmhouse and a really dark site… you're good to the environment so you have really good blinds and curtains both up to make sure that no scattered light gets out your window, and you're hanging out in the kitchen making hot cocoa before you go out to go observing, then you step outside into the pitch darkness of your farm country home and you look up…. and you don't see a thing. You have to wait for your eyes to dark adapt. Now the thing is, is if you're someplace where you have your neighbor's security light within your line of sight, you're someplace where you have streetlights within your line of sight… that's what I had growing up, I would go out to observe in the driveway but we had streetlights because I lived in the suburbs with sidewalks and lots of safety stuff. And all of the streetlights, the second your eye catches them… your eyes… they constrict and now suddenly your eyes aren't sensitive enough to see the faint stars. So there's a lot of places that if you could just somehow stick yourself in the bottom of a well–a very short well so you could easily climb back out–by not having any lights within your peripheral vision, you're suddenly able to see far more stars. And even though it's not safe, if you're in a city, the best place to go observing is down that dark spooky alley where there's no windows facing the alley. And from that dark scary alley you'll be able to make out the stars between the buildings.

Fraser: So let's say that you live in a city with bright lights, bright skies, and you want to truly appreciate dark skies, you want to see the Milky Way for the first time… what do you have to do?

Pamela: Well, the easiest thing to do is look at a map, find the nearest completely empty space, and drive there. You need to find someplace where there's just not humans around. And a lot of times you don't have to go very far. From Austin, Texas we'd go up to a state park called Canyon of the Eagles. It was a nice large park and there was an observatory in the center, and from a lot of the different camp sites you can still get really dark skies… you just have more trees when you're in the camp sites. Find that nearby park, and there's also a lot of places called starlight reserves, dark sky parks, which are large areas of acreage that are set aside specifically to try and keep a place where future generations can go out and see the stars that are disappearing one by one to the people who live in communities.

Fraser: Yeah, in Vancouver there's a dark sky park out in the Fraser Valley, sort of out by a town called Abbotsford, and I've been out there a couple of times. It's out of the city but then there's a mountain that blocks… that's right in between you and Vancouver. So a lot of the light coming from Vancouver is blocked off there, and it's almost like when you come around the corner to the dark sky park, everything darkens much more and you can really see a beautiful night sky. There's a great astronomical community that sets up telescopes there and you can go out and look through people's scopes… it's great. So, I know there's a bunch of them in Canada… I'm sure there's a bunch in the U.S., and even around the world. So if you could find your nearest dark sky park… but how far… let's say you live in–I don't know–Los Angeles… you know, how far north up into the Mohave, how far would you have to get before you could really start to see some dark skies?

Pamela: The dark, dark skies…. three hours out of a city is enough. McDonald Observatory, which is one of the darkest sites in North America, is located 3 hours from El Paso, 3 hours from Odessa, and it's a boring, boring, boring drive… but that drive's worth it. It's basically the edge of an equilateral triangle from these two cities and there is often the horizon… you do see some light… Ft. Stockton's out there, but more importantly, there's some little retirement communities cropping up on the sides of the mountains, but those 3 hours are enough to get some of the nicest skies in the United States.

Fraser: Yeah, so even 1-2 hours out of a town… 3 hours if you can find a really dark place… you know go camping…

Pamela: One of the easiest ways to find a bunch of really nice dark sky sites is find out where the astronomy clubs are meeting. There's all over the place different star parties run by different regional and national organizations. There's the Texas Star Party, there's Stellafane, there's the Winter Star Party that's held out in the Florida Keys. Look for these lists of star parties, and then look to see where they're located, and those are the places that you want to go.

Fraser: Is there a direction you want to head? Is it better to head north or south, east or west?

Pamela: It depends on what you're trying to look at. So for instance, if you know there's some specific comet… there's not any really interesting ones right now, but should, when you're listening to the show, there's some awesome comet in the sky… if you're in a city–figure out what direction is the comet in, and drive in a direction where the city is 180 degrees around the sky from you. So, say that there's this amazing comet that's in the north, well that means that you want to drive north from the city so that the city is behind you in the south, and the comet's in front of you in the darker part of the sky in the north.

Fraser: Right, and I guess it depends if you're trying to see something near sunrise or sunset?

Pamela: Right. So there, if you're trying to find something that's rising right before sunrise, well that's something that's going to be up in the east so head east out of the city and leave the city behind you in the west.

Fraser: Right, that way you have the best chance to see it rising up.

Pamela: Exactly.

Fraser: Then what other things… if you want to adapt your eyes–how long are you looking at? What are some good ways to do that?

Pamela: In general, 20 minutes is the right amount of time to get your eyes fully adapted. They'll keep getting a little bit better after that, but 20 minutes is enough to get most of the way there. And even after 5 or 10 minutes, you start to see amazing differences. Any of you who've had a spouse turn the light on and off on you after you've gone to bed, know the "oh, God, I'm blind!" moment followed by the a few minutes later…. oh, I'm fine again, just looking at random light coming in through your bedroom window. It helps not to drink caffeine… it also can affect things. So basically look for chemicals that won't cause your eyes to act in funny ways. So basic common sense… And keep yourself well-hydrated… that always helps everything.

Fraser: Let's say you've got your eyes adapted, what can you do to protect them? Like if you're trying to…. people turning on lights… things like that…

Pamela: Right. So, star charts are all of our friends… I admit I use them all the time and computers with star charts also exist. The thing you don't want to expose your eyes to is light that's white or blue, or any color other than nice deep red. What people most often do, is that they get sheets of red cellophane and they coat all of their flashlights, they coat their computer screens. A lot of software has night-sky viewing modes that will take over your whole computer, so if you're using some of the software… Bisque software… it has a night-sky mode such that when you open Excel, Excel will still have deep-red background with black letters on top of it. This will help protect your eyes. Flashlights, of course… I actually go the extra step further because red cellophane can come off no matter what amount of duct tape you use… you can puncture it… some mistake can happen. Red nail polish–you may be a guy and you may feel weird buying the red nail polish, but painting red nail polish on the front of your flashlight… try one coat… turn your flashlight on. Try 2 coats… it's a good way to get the precise amount of shielding that you need that allows you to just barely make out what your star chart says.

Fraser: That's a good idea. And that does the trick… you've done that…

Pamela: Yeah, it works perfectly.

Fraser: Because I… often you can get from like army surplus stores… they have these army flashlights and they've got a whole bunch of different filters you can stick in front of the flashlight… you unscrew the front and stick in a red filter and screw it back in, and those are pretty good. But I can almost imagine that they're not dark enough… like they're dark enough if you're trying to sneak through the forest with your comrades, but maybe not dark enough if you're trying to make sure that your eyes are perfectly… stay dark… oriented to the darkness. So you may want to take one of those and even, as you said, put more nail polish on it to even darken it further. That's a really good trick.

Pamela: And Maglite also has those filters and they're not bad, so if you're doing a public event where you're still going to want to use the red flashlights, but you know that there's going to be people with car headlights now and then… it's a cheap option that doesn't require the humiliation of going to the nail polish section. But, there's other things that you have to be aware of, especially if you're doing star parties and you're with a bunch of dark-sky friends and it's not open to the public… closed… you're there to observe. Parking lights on cars are evil. I actually had a student… he was awesome… he popped the fuses for his car's lights because he had daytime running lights, he had back-up lights, and he had parking lights, and they'd all randomly turn themselves on and off and he'd just pop the fuses for them… put the fuses back in when he got out of the dark sky site. It worked. It was slightly insane… I think he drove with his door open so that he could keep the car going along the little line on the side of the road… but it worked.

Fraser: Right, and even just opening up your car…. the dome light comes on… arrgghhh! It's a bright white light and boom–your eyes are wrecked.

Pamela: And laptops…

Fraser: Yeah, open one of those up… or even like a cell phone will get ya…

Pamela: And the problem that you have to worry about now… and this is where duct tape becomes your friend… or electrical tape also works really well and comes off easier… is my Mac has a heartbeat, and there's the little green light on the power supply… and so all the things that would annoy you in a hotel room are way worse when you're at a star party trying to protect your eyes while trying to use your computer.

Fraser: And I guess, then, the last thing that we wanted to talk about today is the battle… the fight to keep the skies dark and to get them back to some kind of semblance of darkness. So, what can cities do to stop polluting the skies?

Pamela: This is really the central issue. We spend somewhere between 1 and 2 billion dollars a year on light where the photons are going into the sky instead of onto the ground here in the United States. And that's a lot of money! That is 1/20 of NASA's budget… somewhere between 1/10 and 1/20 of NASA's budget… I'd love to see that money instead go into research, go into feeding people, going into all sorts of other programs, but no… it's going into illuminating things for astronauts. The best thing you can do is figure out what are your lights actually lighting up and then replacing them with lights that light up what you meant to light up. The most egregious form of light is the nice historic pretty ones where you have a pole, and you have at the very top of the pole a light–usually in a globe… and the majority of the light is going straight up into the sky… and there's actually a shadow cast around the base of the pole. So, if you're walking along at night through a park that's lit up with these nice pretty historic-looking lights, a mugger standing up against the base of the pole would be really hard to see, and you also end up with these circles of darkness with these larger circles of kind of brightness around them, and the trees are really nicely illuminated… and I'm not worried about attack by squirrel in the middle of the night… by getting lights where you have the lights on little arms and all of the light being pointed straight down like a lot of parking lots have… those are much better. You want to replace incandescent bulbs with LEDs or fluorescent bulbs. LEDs are in many ways the most cost-effective way to go because they take so little energy, and you have to replace them–but very very infrequently.

Fraser: Right. And they're throwing out photons in a nice straight line from wherever they're being emitted. It's not like a… something that's being heated up… a coil or a circle and the light just coming out in every direction.

Pamela: Yes… so just a plane panel of LEDs… it's low-cost in terms of longevity. It'll cost a lot more to set up initially, and I know at the end of the day you have to worry about how much money do I have this month, not how much money do I have in the next 3 years, but once you've made that initial investment, you're protecting the sky.

Fraser: Well, I actually found that Walmart is selling LED lights now… like light bulbs….

Pamela: Really?

Fraser: Yeah, I just bought a bunch a couple a weeks ago. I went to Walmart and they have a whole big wall of the fluorescent ones, and then they also have a bunch of LED lights, and these will fit into your light bulb socket… and they use 4 Watts, or 1 Watt… it's quite amazing. Now they're not very bright, they're definitely not a replacement, but like, for example, for the kids… I give the kids… they both have LED lights for their rooms and they just read with those lights, and if they forget to turn them off, it's no big deal because they're just sipping power. But outside… same deal. You put one outside and you can illuminate an area so you can not trip over your front steps but you're definitely not wasting energy and not firing lights up into the air. Yeah… check out Walmart… you'd be amazed at what they've got now in terms of LED lighting.

Pamela: That's cool. See we replaced all of the lightbulbs in our house with compact fluorescents and we just haven't had a bulb go out… So in three years….

Fraser: Yeah, well that's so… you know, that's so "two years ago." Now it's all LED so…

Pamela: Yeah, we bought our house 3 years ago, so we're all "three years ago." That's awesome, and protecting dark skies has so many different consequences. We've found that human beings… that if you're in a brightly-lit bedroom, you're not going to sleep as well as you would if you were someplace completely dark, so that streetlight outside your window that's illuminating inside your bedroom instead of on the sidewalk, that's a health hazard to you. Migrating birds get confused by all of these bright lights. Moths… we have problems with our ecosystem because things eat moths and moths are attracted to lights so the things that aren't near the lights that would like to eat the moths are in trouble. The moths aren't finding each other to reproduce, and lightning bugs can't see each other anymore… imagine you're a poor innocent lightning bug and you're flying around in someone's well-lit front yard at night and you can't find your buddies. There are all these things that we just don't think about. Sea turtles everyone knows about, but the lightning bugs… it's so obvious in some ways and yet so easily forgotten.

Fraser: So, you know, take responsibility. Swap out your big flood lights and your bulb lights for things that are a lot more directional… things that can just cast a beam down to the places you want illuminated outside. And really, you know, does it really matter to have some corner of your property illuminated?

Pamela: Yeah, does the frog really want to be lit up at night? And, use motion-sensitive lights. If you're worried about crime… it'll light up for every single one of the neighbor's cats… I guarantee it, but that's ok.

Fraser: And then you want to take things to another… to a higher level and nag your city. Right?

Pamela: Yeah. And there're lots of organizations out there to help you. The International Dark Sky Association is there. There's an IYA Cornerstone Project–Dark Skies Awareness. And there're people that are documenting how bad it is in different places. Globe at Night and the World Wide Star Count are two projects… Globe at Night occurs roughly every March and the Great World Wide Star Count occurs roughly every October. This year it'll be October 9th – 23rd in 2009.

Fraser: Right, and that's coming up, so if you want to get involved… chart your crappy skies… this is your chance.

Pamela: And both of these sites… they give you star charts and they send you out and they're like… ok, what can you see? Tell us! And then you can use this data to go into your community. And if you want to be really qualitative quantitative [ed.], there's an instrument called a dark sky meter that you can take around to different sites in your town and measure how much light there is in the sky, and say… look, there's this one rural neighborhood that has no city street lights, and it's really dark skies… and look, the crime rate is low. Here's this other place that has the same low crime rate but it's filled with street lights, all the houses are illuminated because they're big and fancy, but the little kids living there can't see the stars.

Fraser: Right. And this is the… I've heard that this is a bit of a fallacy… that criminals like bright city lights as much as anyone because that lets them see what they're doing.

Pamela: Exactly. I can't even stick my key in my doorknob at home… how can you pick the lock if you can't see it?

Fraser: Yeah, exactly… so that doesn't necessarily make sense. So there are a bunch of organizations that you can get involved with who are trying to battle to get these better lighting systems put into cities. There are groups that will help you get involved sort of at a scientific level to chart the state of the skies right now. So, there are a lot of ways to get involved. So, I think for both of us… if you haven't seen the Milky Way with your own eyes….I mean we've already nagged you about Saturn… see Saturn in a telescope! But if you haven't seen the Milky Way with your own eyeballs, organize a trip with your buddies… get out into the wilderness and see the Milky Way. Get up at four in the morning and go outside…

Pamela: And those of you in the southern hemisphere, you're losing the Magellanic Clouds, too, and that's just wrong, those are cool!

Fraser: Yeah… I've never seen those. Alright, well thank you very much Pamela, and so hopefully next week will be the DragonCon episode, and then back on to our regular shows. So we'll talk to you… whenever we talk to you next!

Pamela: Ok, sounds great Fraser… I'll talk to you later.

Fraser: Bye.

Pamela: Bye-bye.

Fraser: This is one of the shows we’ve had a lot of people ask us about, so I’m really glad to be able to do this one.
 
Astronomy is one of the few sciences where amateurs can make a meaningful contribution to the advancement of science. Many professional researchers work hand in hand with teams of amateurs to make discoveries that wouldn’t be possible without this kind of collaboration.
 
We’ve got a special guest here today – Pamela, you do this kind of collaboration. Why don’t you regale use with a tale of your research?

Pamela: I’m a variable star researcher. I study these little stars called RR Lyrae stars that are perhaps most famous for all pretty much being the exact same luminosity. This means these lights are all their own little moral equivalent of 100W light bulbs. When we look at them, we measure how bright they appear and we can figure out where in the universe they’re located by knowing the luminosity. I’ve used this example a million times, but it’s the same way we’re able to figure out how far away cars are at night by looking at how bright the headlights appear.

Fraser: How do amateurs come into your work?

Pamela: Well, RR Lyraes are most famous as standard candles. That’s not why they’re most interesting. These little pulsating variable stars, over the course of human lifetimes, can actually be seen to evolve and change. If you watch them night after night, year after year, you can see their periods change, you can see them occasionally pick up, you can see them go through these weird multi-period effects where it’s like 2 windshield wiper blades that aren’t quite in sync. Sometimes they’re both moving to the left, and sometimes one is going to the left and the other is going to the right.
 
When you get these periods beating against each other, you get the same sorts of beats and increases and decreases in how the star’s behaving. These really weird stars are the ones that interest me.
 
But it takes lots and lots of nights of telescope time to understand what’s going on. Telescope time at national observatories and university facilities is extremely hard to get. By working with amateurs, who are generally happy to look at the same star night after night, month after month, I’m able to get enough data to de-couple all these different weirdnesses that are going on.

Fraser: What kind of setup would one of your contributors have?

Pamela: A lot of the people I work with have your normal, off-the-shelf Meade or Celestron telescope. Something eight inches in diameter or bigger is good for getting into the harder science – 12 inches is just about perfect.
 
Attached to this is a special type of digital camera called a CCD. They’re generally made for amateur use by SBIG Corporation (Santa-Barbara Instruments Group) and by a company called Apogy. These special digital cameras are used with filters that only let certain colours of light get to the detector. This allows people to take data all over the world and then combine the data together to get one great combined data set.

Fraser: Okay, so let’s say you’re interested in astronomy and you want to contribute. What kind of a budget would you be looking to lay out for that?

Pamela: You’re probably looking to spend about 5 thousand dollars, as an initial buy-in, to start doing good, hard science.

Fraser: But you’re going to be able to use this telescope for…

Pamela: Everything.

Fraser: …pretty astro-photos and showing your friends Saturn, as well as doing hard science.

Pamela: This is a telescope you can use for everything.

Fraser: Right. Okay.

Pamela: So you’re doing the digital imaging. You’re doing filtered scientific imaging. You’re looking at pretty objects with your eyes by pulling the CCD off and putting the eyepiece that came with the telescope in. It’s a very versatile, flexible system.

Fraser: Maybe in the show notes, we’ll describe what we think the perfect setup for that. This is not going out with binoculars and your eyes and learning your constellations. This is the next level of stuff, but at the same time what are the rewards? I mean, beyond contributing to the knowledge of humanity… you can get your name in journals, even speak. I’ve seen some pretty neat things happen in these kinds of collaborations.

Pamela: I’m actually in the process of putting together two different research papers where other than me, all of the authors are going to be amateur astronomers that I have collaborated with on two different projects. In one case, the first author on the paper is one of the people that I’ve worked with through Swinburn Astronomy Online, who’s an amateur astronomer who’s been taking some online classes to work to get an advanced degree in this thing he does as a hobby.
 
You can see your name in the peer-reviewed literature, but I think the most cool thing that comes out of particularly studying variable stars is you can, over the course of a single night, see a star change. You can watch it get brighter, get fainter and its behaviour from night to night isn’t always identical with the RR Lyrae stars I study in particular.
 
There are other types of stars that are misbehaved out there as well. You can just watch their strange variations and get involved in why it is. Not everyone is sure. We don’t really have solid reasons for some of these misbehaviours that are going on. The data that normal people in their backyards are taking is the data that is someday going to help us solve these mysteries.

Fraser: I think as well there’s a certain amount of innovation that’s going on with some of the people with the smaller telescopes. They’re having to learn some tricks, having to learn some image processing techniques. There’s actually something they have to teach the professionals again. It really is a true collaboration.
 
This is going to sound like a total laundry list, and I apologise in advance. We kind of brainstormed all the areas we could think of and I can’t really think of a way to string it all into some kind of logical narrative.
 
We talked a bit about variable stars. Why don’t we start with that? What are the kinds of variable stars that amateurs can help out with?

Pamela: The best way to get involved is to check out the website of the American Association of Variable Star Observers (AAVSO). They have a lot of different ways that you, as a normal person with a telescope, can go out and get involved in doing real science.
 
There’s variable stars that intrinsically vary – RR Lyraes, Cepheid stars…. These are individual stars that are changing in brightness. You could also study binary stars. These are stars that appear to vary, but it’s really two stars with one that’s passing in front of the other. We can use data to figure out the masses of these stars, the distance to the stars, how their orbits are evolving over time.
 
There’s one type of variable stars called cataclysmic variables where one of the two stars is sucking material off of the other star. Occasionally these flare up as nova events.
 
There’s recently been a set of Hubble Space Telescope images that were taken for Paula Scodi, a researcher out in Washington. She got ground-based data from amateur astronomers to support this data. If this particular cataclysmic variable she was observing had gone into a nova event while Hubble was looking at it, it would have been too bright for Hubble’s instruments. She needed to work with the amateurs to make sure her star stayed nice and non-nova for the duration of the Hubble observations.
 
There’s also the biggest boys of all, the supernova. There are still amateur astronomers out there who search the sky by eye and by digital camera night after night, imaging in some cases hundreds of galaxies looking for that one elusive supernova that might crop up out of all these galaxies.

Fraser: With the supernovas, that’s really important. A lot of astronomers need to study those, right?

Pamela: Supernova get used for a bunch of reasons. There’s the whole standard candle thing that we’ve all heard so much about. But you and I are made out of supernova material. So by understanding the nearby supernova that are close enough we can get good images, we can get good spectra, and we can measure how much of all the different elements is getting produced in this supernova event. By looking at these nearby supernova events getting discovered by amateur astronomers in many cases, we can better understand where the stuff that made you and I originated.

Fraser: From what I understand, the techniques for finding supernova is a little different. With a variable star, you just point your telescope at the object and report over a long period of time and send in your observations. With supernova, you don’t know where you’re looking. You’re just scanning the skies based on your knowledge of how bright a galaxy should be, looking for a strange star in one of them.

Pamela: The supernova discoverers are some of the most amazing observers in some respects. I got a chance to know one out at McDonald Observatory, Bill Ren. He’d take his telescope out and every night he’d scan through over a hundred galaxies with his eyes, jumping from one galaxy to the next, to the next to the next. He’d memorized what all of these galaxies looked like. As he jumped from them, he’d be looking for changes where any change he saw just might be that next great, cool, supernova that everyone turns to look to.

Fraser: So that’s where the training and where the amateurs have something to tech the pros.

Pamela: Yeah, we can’t find anything on our own.

Fraser: What about finding planets? I know the search for planets sometimes involves dimming the light of the star, making it a variable. Are amateurs involved in that?

Pamela: This is another place where amateurs are out there keeping up with the big boys with the big telescopes. There’s an organization called transitsearch.org, and they go out and study the stars that have planets transiting them. They’ve gotten together pockets of amateur astronomers to help out in this.
 
There are a number of planets we know of that cross directly between us and the nearby bright star they orbit. We can see at sometimes just the 1% level (or even less than that – the 0.1% level), the light of the star dimming as the planet passes in front of it.
 
Even though this is such a small change in the brightness of the star, if you have a four-inch telescope, just a little one, and you calibrate it really well, it’s possible to go out and observe planets in your backyard from a dark enough location. That’s really cool.
 
Again, these are things amateurs have already done.

Fraser: I guess the problem with observing extrasolar planets is that you don’t know where to look. If you find the right star, with the planet moving in front of it on a regular basis, you could have that dimming of the light by 1% on a periodic basis, but the problem is there are millions and millions of stars to look at.
 
This is one of those situations where many eyes makes light work. Many different astronomers can be looking at many different stars and recording. You’ve also got to record over a long period of time. You can’t just look one night and go “no planet�. You’ve got to watch one star for night after night after night after night, watching for that dimming, right?

Pamela: Transit searching for amateurs can fall in a couple of different ways. It can be just as simple as someone with a big telescope doing spectroscopy and looking at Doppler shifting, finding the star has a planet and seeing if we can go out and see it as a transient.
 
Or it can be what you just said. You go out and observe a chunk of the sky, say an open cluster of stars – a large busy section filled with lots of stars. You look at this field night after night after night. You find the RR Lyraes in it, you find Cepheids in it, you find the binary stars in it. You also find those occasional stars with those tenth of a percent changes in magnitude that are varying because they have planets.

Fraser: I wonder how long ago people could have found planets. I guess a big part of this is the technology. You’ve got these CCDs that can measure the light coming in from an object with such precision that you can know the light is decreasing by 1%. It would be hard to look through photographic plates and go “that object’s 1% dimmer tonight�

Pamela: Just 10 years ago, people struggled to be able to do this. Once we started finding planets, it was a struggle to look for the transits. Now people are doing it with four-inch telescopes. The technology, the digital cameras have gotten much more precise, much lower noise, and it starts to make these sorts of detections possible.

Fraser: There’s the micro-lensing too, right?

Pamela: Another way we can find planets around other stars is when a nearby star passes directly in line with a background star. The star’s gravity can cause the light from the background star to appear to get brighter because some extra light beams that were originally headed off to a different part of the universe, get bent due to gravitational lensing to point directly to us.

Fraser: We did a whole show on this, so if you want to reference how the gravitational lensing works, you can listen to our show on it. But to recap…

Pamela: In a few cases you get: foreground star lenses background star, makes background star appear much bigger, and then as this alignment starts to change, you see the background star getting fainter and fainter and fainter. Occasionally you’ll get this second spike. This second spike is caused by a planet going around that foreground star also passing in front of the background star and adding its own little bit of lensing to the game.
 
We’ve found some of the smallest planets we know about because of their gravity, not because of them transiting or causing Doppler shifts. These are planets that are out in the edges of the Milky Way in some cases, and we have no other way of finding them.

Fraser: This is one of those situations where astronomers detect the transit and then they make an announcement to a whole group of amateurs to point at it. The amateurs can watch the transit and confirm if there’s a planet or not, and the details of the transit. So once again this is a great example because in many cases it’s hard to get big telescope time at the drop of a hat. In many cases you can inform a large network of people and they can go out within the hour and see if they can confirm the transit or the micro-lensing.

Pamela: One of the things you can do with amateurs much easier than you can with professionals in some cases, is get a whole group of them together that are spread all over the globe, and get 24-hour coverage of an object. If you can find something near the celestial equator, you just bounce from nation to nation (and in some cases hemisphere to hemisphere), drawing together Canadian observers, New Zealand observers, Japanese observers, Turkish observers, bringing in people from all around the globe to look at one micro-lensing event, one supernova.
 
Gamma ray bursts are another place that amateurs get involved looking at the gamma ray burst afterglows. There are so many different ways that professionals just couldn’t do the science they want to do without amateurs being out there willing to help out and willing to invest the money to have fun contributing to science.

Fraser: All right. We’ve talked about a bunch of stuff that’s outside the solar system. Let’s talk about stuff amateurs can help with inside the solar system.

Pamela: Yeah, we haven’t escaped the solar system, have we?
 
[laughter]
 
Let’s start with the Sun. One of the things we keep track of is how many Sunspots the Sun has at a given moment, where they’re located on the Sun. this is how we tell we’re coming out of solar minimum: when do we start getting spots on new parts of the Sun, when do the spots jump from the equator to the poles. So we have networks of amateur astronomers around the globe who count Sunspots.
 
We also have amateur astronomers who use radio equipment a lot of times home-built, to listen for bursts of the Sun’s energy hitting our atmosphere and creating solar ionospheric disruptions (SIDS). These get recorded. This is again something you can work with the AAVSO to do. Our Sun is one target.
 
Another target, and in fact something that allows you to potentially permanently make your name part of the astronomical record, is looking for comets.
 
Nowadays, there’s so many different automated telescopes that the majority of the comets are starting to get found by these automated systems, like LINEAR – we’ve all heard of different Comet LINEAR-this or Comet LINEAR-that. They’re not all the same comet, but people like David Levy are still out there searching by eye for comets that are their own comet. You can go out and look for comets. If you find one, your name gets to go on it. People are still finding new asteroids pretty much everyday of the week.
 
There is a lot of junk out in our solar system, just waiting to be found by someone patient enough to look for it and then report it correctly. Harvard university has an entire minor planet association there where you can get checked out and contribute in three different ways. You can follow up on objects that are well-known and help refine the orbits.

Fraser: Hold on a second, can we talk about that for a second? That’s pretty important. The stereotype when astronomers discover an asteroid is an astronomer looks through the telescope, spots the asteroid and goes, “oh my God!�
 
[laughter]

Pamela: That is so not true.

Fraser: “That’s going to hit the Earth!�
 
But that’s not what happens at all. It’s a painstaking process where people watch it and watch it and watch it, and refine their orbit over time. So once again there’s only so much telescope time the big observatories can dedicate to watching that random jumble of letters, 2007GR 906. But if an amateur has the time and equipment, they can watch it and determine its location and report in, a week later give another reading, and really help astronomers refine the location of these rocks.

Pamela: This is one of the more important things that you can be involved in. we occasionally misplace things because we don’t know their orbits very well. We see them on one pass around the Sun, and on their next pass we have no idea where they went. Individuals going, “hey, this object needs more data,� are able to help us better understand how things are moving around in our solar system.
 
Then there’s also just follow up on discoveries. There’s the objects we sort of/kind of know, but we need more data to understand them very well. Then there’s the objects that are brand new that no one’s ever seen before. We need to confirm those. You can get involved by saying, “I just got an alert there might be a new object. I’m going to follow up on this and help confirm if it’s a new object or not.� Is it just somebody had a crazy lightening bug interfering with their data? (not that I think that ever happens, but I’m trying to come up with something that could interfere with data)

Fraser: Right.

Pamela: But you do occasionally discover new things. You’re out there taking images of Saturn and you do this three nights in a row and notice one of the stars in your image is slowly escaping. That slowly escaping star might just happen to be an asteroid that happens to be lined up with Saturn when you’re taking pictures.

Fraser: What about some of the actual planets in the solar system. Is there stuff that amateurs can spot?

Pamela: Storms. Just as there are storm chasers here on planet Earth, there’s also storm chasers that are the first ones to call out, “hey – Mars has a huge dust storm coming up!� Mars now has its own network of weather satellites, but at the same time amateurs still play a role in helping understand these.
 
Jupiter’s junior red spot, when it changed colours it was an amateur who noticed it. Tracking the spots on Jupiter is something amateurs participate it.

Fraser: I hate to belabour this point, but I think that most people really underestimate how much of the sky is being observed at any one time. I think people have this idea that there are telescopes watching everything out in space at all times and they see everything going on. In fact, telescopes can only see a teeny-tiny slice of sky and can only look at a couple of targets a night. In some cases, Hubble will take pictures that will be of the same object for dozens or even hundreds of hours. There’s no way they can look at anything but one tiny little target.
 
To have all these eyes out there, all the time, looking at as many things as possible, lets the astronomers catch the stuff they never really thought of. How could the people not notice there’s a new storm on Jupiter? The reality is people aren’t watching Jupiter everyday. They just don’t know – and they’re not keeping really, really careful measurements about what they’re seeing.

Pamela: It’s not just looking at the sky to observe parts of the sky that aren’t being observed (and there’s a whole lot of parts of the sky that aren’t being observed). Just for perspective, the moon is about 30 arcminutes by 30 arcminutes in size. The telescopes I used for a lot of my dissertation research had a field of view that was 7 arcminutes by 7 arcminutes in size. They couldn’t even see one ninth of the moon.
 
If your typical professional telescope is lucky to be able to see one ninth of the moon, which doesn’t take up a whole lot of sky… the majority of the sky at any given moment isn’t being observed by anyone.
 
As well as trying to keep track of what’s going on in the sky, there’s a ton of data that’s getting taken by automated missions, different satellites, automated telescopes that also needs people to take a look at it. One of the most famous examples is looking for Sun-grazing comets in SOHO images. That’s somewhere where there are lots of amateur data-mining astronomers who are sitting in their living rooms poring over data and pulling out and discovering all these comets in the process of zooming to their doom.

Fraser: You don’t even need equipment for this. This is one of those situations where you can sit at home with an internet connection, the right data and be able to pull up discoveries.
 
Another great example of that is you look at the Sloan Digital Sky Survey, which is one of these automated network of telescopes observing vast swaths of the sky (a percentage of the sky, I don’t remember the final number will be, 20-30%) at a pretty high resolution. All that data is available on the internet. When I write articles on Universe Today, many of them are like, “this team was looking through the Sloan Digital Sky Survey to measure the brightness of quasars� or “this team has turned up 10 thousand unknown asteroids�. In many cases it’s more about being a good programmer and knowing how to grind through that data – being a good database analyst. So in many cases if you’re a programmer or a database researcher… there are lots of ideas people have, they just don’t have the time or software to grind through this automatic data.
 
I think another good example is the Galaxy Zoo is pretty cool. Have you played with that yet?

Pamela: It’s a really neat thing. The data they’re getting with Galaxy Zoo… just having individuals look at galaxies by eye (because humans can visually classify things better than any computer can), by just going through, looking at these things and saying, “yes, the arms are wound clockwise/counter-clockwise, we’re looking at it edge-on. This is an elliptical galaxy. This is something so irregular it looks like the letter Q�.

Fraser: A computer does a really terrible job of grinding through the Sloan data, but a human can really spot them and say that galaxy’s left/right/spiral/elliptical.

Pamela: This is data that astronomers have been dying to get. The sky is so big, there’s so much to do, and it takes human eyes to do it. To do statistically valid samples – to look at 10 thousand objects, you’re either looking at torturing a whole pack of graduate students for 3 or 4 years, or sending out to the entire population of the world and saying, “hey world – help me do science�. We’re finding people are more than willing to help out if you just give them the tools.
 
They’re doing some really amazing things with Galaxy Zoo and they’re also having fun. One project going on the side is trying to find galaxies that look like all the letters of the alphabet. While that’s thoroughly silly and not really leading to great science, it’s the type of thing that will get people interested in looking at the science. While they’re looking for the elusive letter Z, they’re also classifying galaxies, and their classifications will allow scientists to statistically valid and significant studies.

Fraser: I know there’s some really interesting research that’s already being worked on right now, and there’s even a couple hints I’ve heard of some almost ground-breaking discoveries that might get made. There seems to be a strange imbalance of galaxies.

Pamela: Once they’re done with the information, I’ve been promised we will be told so we can…

Fraser: announce it.

Pamela: … bring it straight to all of you.

Fraser: Then there’s SETI@Home. Once again you don’t even have to be there – just turn your computer on, let it crunch through data, and find aliens!

Pamela: And occasionally find things like pulsars and other things that make systematic noise in the sky.

Fraser: Then, there are some things you can do outside anyway, that doesn’t necessarily require your computer. It doesn’t necessarily require a telescope. I’m thinking looking for meteors.

Pamela: Every year we get a whole bunch of meteor showers – the Leonids, the Perseids, the Geminids are coming up next week.

Fraser: Yep.

Pamela: To help us better understand the distribution of the junk in the solar system, left behind by the comets and asteroids that formed these meteor showers, people can go outside and just draw on a celestial map where the meteors they’re seeing seem to pass through the stars, and write down the times.
 
By writing down the positions and the times of all the different shooting stars you see, we as astronomers can better map out where the tail of Comet Enke is, or the tail of all these other objects that have led to these meteor showers.

Fraser: Is there a place people can go to turn their data in?

Pamela: Sky and Telescope Magazine, every time there’s one of these coming up, lists the appropriate body for the particular storm that’s coming up. They’re a great resource for finding where to report your meteor shower findings.

Fraser: I usually send people to amsmeteors.org, which is the American Meteor Society. I also get emails fairly often from people who say, “I saw something really bright flash through the sky. What was it?� I tell them to report it as well. If you’re just outside at night and you see a really bright fireball, that’s very important. You can report that to one of these meteor agencies. We’ll put a list of places in the show notes as well.

Pamela: One other resource that’s useful is the website heavens-above.com. It will tell you if you actually just saw a satellite. There are some satellites up there that do make fairly bright appearances in the sky. You can sort out the meteors from the satellites by going to heavens-above.com

Fraser: I’m looking through our laundry list of things that we thought of. There’s a couple I think we missed or weren’t able to categorize. One is occultations.

Pamela: Occasionally, we’ll see asteroids or even planets or the moon go in front of background stars. By getting a bunch of people all across the planet, they can look at these occultations. We can actually start to determine the shapes of asteroids, or the shapes of mountains on the moon a lot more accurately. This is another thing people can get involved in. there’s an international organization: IOA, the International Occultation Association. Get involved and go out and just watch a star wink out and time what time it occurs.

Fraser: What if you find a meteorite on the ground?

Pamela: This is one of the great mysteries: I found a rock. It might be a meteor – what do I do with it? Take it to your local geology department. If it is real, they might be scientifically interested in it. Here in the United States you actually get to keep it. You can probably make some scientist’s day by going, “here, do you want to play?� and letting them take slices out of it to see what our solar system’s made out of.

Fraser: We’ve got a couple more here: auroras?

Pamela: You can look and see how it is that the Sun’s particles that it spews our way interact with the Earth’s magnetic field by looking up, observing what colours you see. A lot of times your local weatherman will report when this is going on and tell you who’s tracking what particular event.
 
The next thing I think you’re going to get to is there’s also galaxies out there that vary similar to how stars vary: blazers. Occasionally you can hook up with researchers at your local university who are interested in active galaxies. If you have larger telescopes (here we’re talking 12 inches and above, and CCD equipment), you can also observe the active feeding of black holes in the centres of galaxies.

Fraser: There’s one last one, which I think is very near and dear to my heart: fighting the spread of light pollution. Many cities are just getting brighter and brighter, and I know that amateurs have been working to try and catalogue just how light polluted the skies are above various regions of the world. In many cases there are dark skies associations that you can report how bright the sky is at night, and they can keep track of where things are starting to go pretty bad. You just need your eyes – no expensive telescope.

Pamela: The International Dark Sky Association and the Globe at Night both do programs to measure light pollution. If you do like playing with technological toys there’s a little Canadian device that’s a dark sky meter. You can go out, use it to measure how dark your sky is, and then report what you measure through the internet.

Fraser: I think hopefully we’ve given the listeners enough of a list of places to get going, that I think you could spend your whole life participating in this scientific research.
 
I really think this whole area has opened up in the last 10 years, with the real advancement of CCD technology and a lot of automated tools that let you guide telescopes. It’s made guided telescopes that can detect this kind of really faint fluctuations in brightness within the reach of most amateurs. You get a really nice telescope you can use it for science at the same time. It’s just opened up the floodgates and really encouraged this kind of collaboration.
 
I think astronomy could really serve as a model to other research fields. I think that in a lot of other places, there’s the scientists and then there’s the amateurs or the enthusiasts. In many cases the difference between someone who is an amateur/enthusiast and someone who’s a professional is in many cases just some additional schooling, but in many cases one person’s a little more street-wise and the other person is more book-smart. I think the more of that kind of collaboration we can help bring together, science as a whole will take off.
 
I’ve said it before, I’ll say it again. We’re in the golden age of astronomy, and this is one of the corner stones of that golden age.

Pamela: There’s no reason to be using your telescope just to look at Messier objects. Do that to inspire people, to inspire yourself occasionally – we all need to take our favourite pretty picture now and then. You can do science: all of you listening right now can go out and do science. Get involved, find some way to help increase our understanding of the universe.

Fraser: We also get the emails from the person who wanted to be an astronomer as a kid and… I don’t know, become a banker. Listening to Astronomy Cast has reignited their interest in science. Here’s the part where the rubber hits the road: if you really are interested in science, if you’re interested in astronomy and want to rekindle the childhood aspirations, there’s a way you can do it (especially if you’re a banker!).
 
There’s lots of ways you can get involved and the scientists really need your help. You’ve picked the right hobby.
 
Let us know! We’d love to hear if you’re already an amateur that participates with a professional observing or if you want to make that transition. Drop us an email and we’ll give you personalized tips and try to match make. If you’re a professional astronomer and need more amateurs, let us know. We’ll try and make some love-connections.