 From the Vermont Astronomical Society, we have Jack St. Louis, who's done his feet, but he's got laryngitis, so he's only going to speak briefly. And then we're going to have Jack as the president of the society, and Terry is the treasurer, so we get to hear from them both. And they even brought some solar eclipse glasses. I don't know if it's enough for everybody, but there's something to give away as well. So I'll tell you a little bit about Jack St. Louis. He's going to give an overview, he and Terry, about the eclipse and explain why eclipses happen, the timing, and how to view it safely. I also asked him to cover, what do we do if it's cloudy? So Jack is president. He's active in the group's outreach and astronomical education, public star parties, and unstructured, structuring club observations. He's retired from the University of Vermont, worked in computer services. He has viewed several partial solar eclipses, but not yet a total eclipse, and neither has Terry. I got to view a solar one in 1972. I was a young in that. I'm not that young. Okay. That was on Prince Edward Island. Terry Zittrich. Zittrich? Yes. His treasure of the Vermont Astronomical Society, a longtime Vermonter, been here for 43 years, came to be an electrical engineer at IBM. She recently retired, and she has three sons that are all living in Vermont. Welcome to both points. This is so cool. Yeah, so I got this great case of laryngitis going on, so it would be terrible if I tried to talk today. So Terry agreed to do the presentation, and it would be fine. As you can see, by our logo, we started in 1964. On May 6th, we'll be, we'll turn 60. It's the same date that the club started. So it's kind of pretty cool. So I've been president for, well, too long. So I think we may be looking at our next president. So the club is, we're activists. We have an observatory in Heinsberg that the club members built. And we use that as often as we can. And we love to do outreach. And we go anywhere people can, if they ask us, well, schools, libraries, we put on presentations, we talk about astronomy, telescope, telescope making, and just looking at the sky at night. And during the day, they have the appropriate equipment. For those of you who do not have a viewer for 50 bucks, no, for free, I have about 100 of these. So it may not go around to everybody, but we got the cards because it's easy to use. You just put it, look up, and you can share it and you don't have to try and wrap it around your head or anything like that. So it's going to go go on it. And we're going to hand them out. So, enough of me, so, Dary's up to do the presentation. Okay, hopefully I won't make too much noise here. I'm going to take this off because I don't stand still. So anyway, thank you for coming out and listening to us today talk about the upcoming solar eclipse. I'm going to warn you up front, I just saw this presentation for the first time yesterday. So I wasn't planning on presenting today, but Jack has laryngitis, as he said. I went to one that we did this morning. So another gentleman in the club presented this morning in Milton and it went really well and I watched that. So that was my learn session. So this is my do. So no report cards at the end. So, as Jack said, we're part of the Vermont Astronomical Society. We have monthly meetings the first Monday of every month. Public is you don't have to be a member to attend our meetings. Our meetings are held in person in Essex Junction at the library and online via Zoom. So since the pandemic, we started Zoom meetings and anybody can attend. So if there's a subject that you're interested in, you can see that on vtastro.org and that's our website address and the viewers have that on the viewer. So that information is on the viewer. So if you see something you like from our agenda and our schedule, feel free to join our Zoom sessions and come listen to us talk about some astronomical subject. So, onward. So, today, we're going to talk about sun stuff and, you know, a variety of sun things. We're not going to go very deep. I'm an electrical engineer, not a solar engineer or astrophysicist and what I do mostly is astrophotography. So I do a lot of photography of lots of faint fuzzy things in the sky. So that's my thing but I also take pictures of the sun so I'm hoping I'm keeping my fingers crossed and I'm going to stay very positive about having clear weather on April 8th at least from 2 o'clock to 4 o'clock. So the rest of the day I don't care but between 2 and 4 I'm hoping it's going to be very clear and we have a great showing. So we're going to talk about the eclipse timing and we're going to talk a little bit about why eclipses happen and why they are so scarce. You know, they don't happen that frequently. In fact, for a particular place on Earth, for instance, having a full solar eclipse happen, say over my pillar, it's very infrequent and we'll talk about exactly what that timing is and we're going to talk about where to look and also what to expect. And lastly, we're going to talk about safe solar viewing. You know, it's very dangerous to look at the sun even though you might not feel it when you're looking at it, you're harming your eyes. So Jack brought some of those viewers with him and we all want people to do safe solar viewing. Okay, so first let's take a look at the sun itself and I will see if my little pointer here works. Oh, yeah. So here's the different, you know, the sun's made up of a bunch of different layers and all the real action, all the real action occurs in the very core of the sun. And the core of the sun is only about 10% the diameter of the entire sun, so it's only about, it's less than 90,000 miles across, which is of course a lot bigger than the Earth, which is only 8,000 miles across, but it's 90,000 miles across and that's where fusion occurs. So fusion occurs deep down in the sun, you know, with all the gravitational forces for all that mass. It's squishing that material, those hydrogen atoms together at such force, they're fusing together and when they fuse they create helium, the next element on the chart. And with that process they also give off energy and heat. And that energy and heat goes through this next layer called the, I believe the radiation zone and it takes, believe it or not, it takes millions of years for that heat and energy to go through this zone. The sun is that big. The whole sun is about 865,000 miles across, so over 100 times larger in diameter than our Earth. But in area, I believe it's more than a million times. So you've got the core where fusion is happening, it's creating all of that extra energy as a result of that chemical process, that fusion process. That heat and energy and radiation is slowly going through this radiation zone that it hits something called the convection zone. So this is where that energy finally goes through the last layer of that part of the sun, gets to what we would call the surface or the photosphere, gets to the top and then cools down a little bit and falls back down and it kind of goes into a circular radiation pattern, kind of like when you're heating a room, you know, the heat rises and it kind of convex. It kind of circulates around the room so that you get all these little convection zones all over and they create some, you'll see in a moment, they create some surface feature that we can see and you can actually see that surface feature in white light if you have a big enough telescope. In fact, I was just looking at them and taking pictures of them yesterday. So yesterday we had some sunshine for part of the day and I was taking pictures of that in the sunspots. So you can see those zones. And then after that convection zone, you have the photosphere and that's what you see in white light. So if you have your solar glasses on or a solar filter on a telescope, you can see that what's called the photosphere. And then after the photosphere, which is a fairly thin level, I want to say that's only about 250 miles thick. It's a fairly thin layer of the sun. Then you have something called the chromosphere, which is I think about a thousand miles. So a lot of action happens in the chromosphere. That's where you see things like prominences. So if you see pictures of the sun, the prominences are created in that area. And then you have this area here called the corona, which is several diameters of the sun wide. So when you take pictures of, for instance, a full, and we'll talk more about it later, but of a full eclipse, like we're going to have coming over for a month, that chromosphere area, so this would be one solar diameter out here, another one here, you might have the area would be very large in terms of the corona. And that corona is also, it's representing the particles, electrons, photons that are being pushed off, off of the sun, and it's part of something called the solar wind. And I'm sure everybody's heard about things like coronal mass ejections and things that cause, you know, radio blackouts or, and we'll talk about more of that in a minute, but that's when they have very large prominences and push off these large amounts of charged particles off of the sun. And when they're pointed directly at Earth, they can cause problems for us. In fact, and they can cause beautiful things as well. They actually are what causes the borealis. So the aurora borealis. So some beautiful sites for us as well. So enough on the sun, on this part of the sun, and then of course, oops, one more thing, we have the sunspots, which are on the, on the photosphere. So talking about those areas, those small convection zones, these little things here you can see when you look at the photosphere layer of the sun, that's the white light visible layer, those little areas are the size of Texas. So those convection zones are quite large and they go, they go well into the sun in that convection layer. So where it's a little darker here, that's where the gas has cooled and here's it bubbling up when it's warmer. And we'll see a picture of the whole sun here in a minute. We'll see what this, what this looks like. And there you go. So this is what you see when you look through a high-powered telescope at the photosphere. You see all these little, you know, it almost looks like cracked pavement or peanut brittle. I don't know, I'm trying to think of what this looks like, but you know, here's the hotter portions of those convection zones and here's the cooler areas. And these are, you know, these are going deep into the sun, these are the areas and just basically rolling over, you know, hot, you know, they heat up, they come to the surface and they cool down and they go back down and then they, of course, heat up again. So here's a picture of, and this is basically what I was seeing yesterday. I was looking in white light yesterday and I could see the, and this is colored, of course, but my filter was actually white. So you see kind of, it was just a monotonic, if you will, view when looking at the sun. But I could see the sunspots, I was looking at the photosphere. This little modeling on here, those are the convection zones. A higher power telescope would show more detail on those convection zones, but that's essentially what I was looking at yesterday. And here is a high-power photograph of the same thing again. Sunspots, those convection zones, which are very interesting. And you'll note how the sunspots look fuzzy. So they look like they got hairs on them. You know, they look like little gorilla heads, if you will. Or pom poms, maybe, is a better analogy. And, you know, a lot of the time or most of the time they come in pairs because they're actually, you know, some of this is created by magnetism. There are magnetic fields around those sunspots like the core of the earth, the circulating core of the earth creates a magnetic field. These create magnetic fields in the sun is just one giant ball of very complex, changing magnetic fields, which you'll see in a second. But these sunspots usually come in pairs and these are magnetic field lines. And they're showing material being carried by those magnetic field lines on the surface. And a lot of the time when you look at these on the edge of a limb, you'll see those field lines jumping up between various sunspots carrying that material and we can see it visually. Usually we can see it visually with something called a hydrogen alpha filter. We have to use special filtering to see those things. You wouldn't necessarily see the material jumping up over the surface with white light. You'd need a special filter for that. But my guess is wherever you're doing your viewing and whether it's in Montpelier and I would suggest going farther north because Montpelier is going to have a pretty short eclipse. They're right on the edge, close to the edge of the full eclipse path. So if you have friends farther north, I'd go invite yourself for, you know, a lunch and dinner at your friend's house farther north to see if you can... Unless, of course, it's going to be cloudy north and you're going to have a clear... So some full eclipse is better than no full solar eclipse. Yeah, we get about... I think the maximum in Vermont is going to be about three and a half and that's up in the islands. Burlington's around 310 and I'll talk... I have a map that shows this a little better and I want to say just north of Middlebury, that's the southernmost line, so Middlebury you're not going to see a full, it would only be partial. And by the way, a 99% partial is nothing like a full eclipse. So a 99% partial is not a 99% experience, it's a 1% experience. So you really want to... That's what I've heard from everybody and I have not seen a full, but I've heard from everybody that I've talked to you don't want to miss the full. So the partial is not the same. I just attended an annular eclipse in El Dorado, Texas. Oh, question. Perfect example. The example given is that the difference between a 99% eclipse and a full solar eclipse and being the 99% solar eclipse is like driving your kids all the way down to Orlando, to Disney World, getting to the parking lot and turning around and going home versus enjoying the wonders of Disneyland or Disney World. And that's basically what I've heard. You want to see the whole thing if at all possible. So and the great thing is is that everybody, if we have clear skies, which we will, everybody gets to be an astronomer that day and the other great thing is you don't have to stay up late for it. So it's right in the middle of the day. So hopefully everybody can be an astronomer for those few minutes. So here's an example of the size of the Earth versus the size of the Sun and that is about, I believe the diameter of the Earth is approximately 8,000 miles and the Sun is about 865,000 miles across. So it's about a hundred times the diameter. And just to give you an idea, this magnet, this horseshoe magnet here, the field lines, this is exactly what you see when you look at a sunspot pair in terms of the material being injected and pulled across from one pole to the other on the sun. It's very unique to see and it changes very fast. So these field lines are amazingly dynamic. Even in the process of me taking a few photos, they are changing. So it's very cool to watch and you can do time-lapse photography of this kind of stuff. So it's very interesting. And here is another image. So again, showing the convection zones. You know, the photosphere up here, the sunspot areas, which are a little cooler. But when I say cooler, they're 7,600 degrees, I'm sorry, they're 4,500 degrees to the photosphere's 7,600 to about 10,000 degrees as the photosphere. The neat thing about the sun is that there's something out here, you know, this thing called the corona that you can never really see unless you have a full eclipse. You can see it with a 99% eclipse or a 99.9. It has to be 100% eclipsed because it's so dim. But the corona is about a million degrees. So it's much hotter and this is one of those mysteries of science. They, I'll say they really haven't figured that out yet. There have been a few things lately published where they have a theory as to why the corona is a million degrees and hotter than the actual surface of the sun. But they haven't necessarily proved it yet. So they're still trying to understand whether this is the right theory or not. But that's a fact. The corona is actually much, much hotter than the surface of the sun. Now, 76 degrees is more than a hot day in Florida. So it would be pretty hot as with the sunspots. So the rest of the sun is also pretty darn hot. So here's a picture of the magnetic fields at a point in time and like I said they're very dynamic on the sun. So lots is happening from a magnetics perspective with all that swirling gas inside of and convecting in the sun. And here is just a 400 years of sunspot observation. So my understanding is that there's a cycle to sunspots and we recently hit a minimum. In fact, I bought a solar telescope and it was in the middle of a minimum. And I kind of figured out why there were so many solar telescopes for sale and they were going cheap because there were no sunspots. There were literally almost no sunspots on the sun. The sun was basically clear. Now with the big telescope you can look down and you can see that you can still see the convection zones. And the surface, but no sunspots. So there were some prominences but very little. It was very quiet. But that ramped up significantly and now we have a very, very active sunspot situation. And in fact it's much more active than they were predicting. And we're peaking faster than they predict. So this current cycle is very positive for sunspots. And also since something about the energy the Earth is getting. And again, this is the first time I heard this this morning. So bear with me a little bit. So they've been keeping track of this activity for since the 1600s the solar activity. And this was a minimal sunspot period. And according to, I guess, records the Earth was a little cooler than as well. And there is some correlation then between sunspot activity and energy being delivered to the Earth. So again, I'm not an expert on this but this is something I just I just heard about this morning so I haven't studied up on it myself so I don't ask me a lot of questions here. But we do have this cyclical nature of sunspots again it's an 11 year cycle and you get minimums, you know maximums and minimums every 11 years. And then of course this a monitor minimum here was a very low point and also a very chilly point I guess in the on the Earth. And right now we're enjoying in the 50s to 2000s we were enjoying a nice maximum and I think we're enjoying a pretty nice maximum right now. In terms of you know the spectrum of light that we see from the sun. So when you shine light, white light through a prism you basically get a rainbow of color. So in the rainbow represents the different wavelengths of light so at the very short you have the purple and the very long wavelengths you have the red. And I don't know if there's a lot more I'm going to talk about here. You know we as astronomers and you know Jack and I are amateur astronomers we look at that I talked earlier about seeing the sun in hydrogen alpha light it's a particular wavelength I think it's 656 point something 0.3 maybe nanometers and you know we can see certain things we can see this hydrogen alpha emission which are what prominences are and a lot of solar activity filaments on the on the sun in the chromosphere and we can look at that with these special telescopes from so from that perspective understanding the different wavelengths of light emitted by the sun is interesting for us and there it is 656.3 nanometers is the hydrogen alpha emission line and you can understand the sun is in a hydrogen burning phase which means it's consuming an enormous amounts of hydrogen and creating helium and it will be doing that for quite a long time some billions of years more and in fact here is a picture of the sun so when I look through a hydrogen alpha telescope this is more like what I see I can see things like and you can see things like prominences filaments filaments are nothing more than prominences on the face of the sun when you're looking at the face so in things called plages and all kinds of of activity on the sun it's a very interesting and it's very dynamic and if wherever you're viewing the eclipse I have no doubt somebody will be around with the solar telescope even before probably before the full eclipse it would be a great time to look through somebody's solar telescope during full totality when it's going to be clear out you should be looking at the full solar eclipse and forget about the solar because you can look at that at any time okay here's some of those you can see the what look like the two poles of magnets that's probably a sunspot group and there's some material being pulled between two sunspot areas and they're only poles and a magnet and here's something so this is when you have a giant ejection of material from the sun so this white circle represents the diameter of the sun this is just an occulting disk so they do this so they can actually see that ejection if you didn't put that disk there the exposure would be so bright you couldn't see the rest it's kind of like what happens when we're looking at a total solar eclipse because you can never see the corona because the rest of the sun is too bright and this allows you to see what's called these giant prominences and ejections of material are called coronal mass ejections and clearly when we're looking at it from this direction it's probably not aimed at the earth which is a good thing because it's high energy particles they're being ejected and flung into space as the solar wind and when these things happen the solar wind is very strong from an electrical energy perspective you're shooting electrons mass with numbers of high energy particles into space and when those things hit the earth they interact with our magnetic field and they come through and they can do disruptions to various things so we've had a few big events in recorded history we haven't been using electricity all that long but in 1859 a coronal mass ejection hit the earth's magnetic field and at that time the only thing people were really using electricity for were telegraphs so these energized telegraph wires and electrocuted people caused fires in the telegraph offices and in fact this is what's been recorded is that some operators after disconnecting after this is happening the telegraph operators disconnected their batteries to save their systems they could use the telegraph without the batteries there was so much energy supplied by the sun put into those systems and this event was called the Carrington event and I'm assuming this gentleman Carrington was a scientist to explain what happened to all the people after this occurred and the next one is the Great Quebec Blackout now I wasn't around for well actually no I was around it was 1989 so March 13, 1989 I was actually in Vermont so I was nine years in Vermont a CME hit the earth's magnetic field and 90 seconds later I guess the Quebec power grid went out now I know I was alive then some of you may have been alive then too so you might have actually experienced that I actually don't remember it but evidently it caused a nine hour blackout in 1989 I remember the earthquake I remember the earthquake happening I guess I don't remember the blackout and that was again caused by a powerful coronal mass ejection so that was a little bit about the sun so now we're getting to about the eclipse we're going to enjoy a total solar eclipse here in Vermont it's going to be clear it's going to start at 2.14pm and the partial portion will last about an hour and 12 minutes so I would enjoy that look through people's scopes you can do all kinds of cool things to see that including during this period you have to wear some eye protection if you're going to look towards us but you can do a lot of indirect things any pinhole or hole if we had leaves in the trees I'd say look below trees because all those little gaps between the leaves and the trees will project like a pinhole camera on the ground and you'll see crescents during the partial phase but we might not have leaves by then my guess is probably not you can use a colander you can poke a bunch of holes you can do a lot of things to make a pinhole projector if you will and that will project it under the ground but that will last an hour and 12 minutes at the start totality only lasts for in Vermont the longest will be 3.5 minutes and like I said that's up in the islands, Swanton everything below will be a little bit less and that will go to just about almost to Middlebury Middlebury Middlebury and Burlington is about 3 minutes so about halfway down from the center you get to Burlington 3 minutes 3 minutes in 10 seconds or so and that's the time you can take your glasses off, no glasses are needed during totality it's about as bright as a full moment in fact if you left your glasses on or your protection on during totality you won't see anything it's not bright enough to get through that filter that filter is very strong light that's coming from the visible sun and then after that you've got another hour and 7 minutes of the partial eclipse leaving so that's the the moon continuing to go across the sun and you know this whole thing is accelerating so that's why the leaving is a little faster than the coming because it's accelerating and I'll talk more about that in just a minute so in the partial ends about 4.30 6 that would be daylight savings time on April 8 so here's the entire path and it starts, sorry I'm I got my screen so tell me if I'm blocking the view so the path starts here down in Mexico and I know some people actually going to the town that's right on the shore of the Mexican Peninsula there and I actually know people all through the path here that are going to be traveling for that so lucky them but it travels up and it actually starts, I want to say that the eclipse is about 4.30 minutes down here so it's actually traveling a bit slower so the moon it's geometry it's got to do with the curvature of the earth and as the earth is curving away farther north that shadow is accelerating so down here again it's I want to say it's traveling about 1500 miles an hour I think it's somewhere later in the slides so passing through quite a few states it's a great time but you know the whole path here this path is only 115 miles wide so it's fairly narrow so it's you've got to and you know you can just imagine there's a lot of people that live in these areas and you know people that live in these areas they're going to be heading into that a lot of people who are interested in this kind of thing which are a lot of people will be heading into those areas we expect an influx of people in Vermont in fact we we tried notifying that we actually sent a letter to Phil Scott like a year ago warning him of this and getting prepared in hand since I haven't been to one that the traffic right after the eclipse is horrendous in fact one of the people the person that did the presentation this morning in Milton had been to one I want to say in Illinois or Tennessee I forget which one I think it was Illinois and this was in 2017 and he said it took him 3 hours to go 10 miles and then they got off the expressway they escaped and did something else for a bit so I don't know if it'll be like that in Vermont but it could be so I would stay off the big roads or try not to get anywhere right away stay put for a bit oh yeah that is correct but let me maybe explain it so the way to think of this this full eclipse area is that there is a shadow that's a circle that's the shape of the moon so that moon shaped shadow we'll have more pictures but that moon shaped shadow is moving across a fairly good clip you can think of it on the edges you're only getting a small arc in fact that the very edge you're just getting a you know you could be just seconds of totality in the center the center is going to give you the longest time you know in Vermont it's going to be about 3 minutes and 30 seconds I guess we're up in here of full eclipse so you don't want to be at the very edge so I think I do have a map here that we've drawn out the eclipse area and if I look at it Montpelier is between the 2 minute and no eclipse line so it's between you know you think of this as this area here as the happy area for the eclipse this is the sad area for the eclipse you want to be on the happy area Montpelier is in the happy area but it's just inside so it's going to be less than 2 minutes you know a minute and something long so but again any full eclipse is better than no full eclipse so try to take advantage of it and be an astronomer on April 8th okay here's again a more detailed so just to be clear this is the bottom edge this is the centerline so all of this is going to be really good here so you know Montpelier is inside Middlebury is kind of on the edge Burlington is very well placed so hopefully all the people in Burlington don't need to travel anywhere you just need a good view of the sky you don't want to be in the middle of a forest oh god you mean all up and down what are the eastern they represent Canada eastern townships oh quick I see yep yep all through here yeah Montreal is up there and they're going to be near the centerline I bet yes to St. Almond wow wow it could be busy it could be exciting you know for the VAS the Vermont Astronomical Society you know besides doing all these presentations you know various VAS club members will be set up mostly in their towns you know will be set up at our observatory we set up and I'll be I'm from Williston so I live in Williston I'll be set up there oh I believe it I believe it yeah and I've actually heard I forget which it might have been Delta Airlines was selling tickets for an eclipse flight so that's kind of a guarantee to be above the clouds that would be very cool so it might be something to do someday for a future eclipse I can only imagine what they're charging for that yeah you don't want the aisle seat for somebody say you want the window seat in that case usually I get the aisle seat I'm tall you know my legs just don't like that cramped corner stuck next to the window but in this case I would suffer I think and take the window you don't think just because the people only want the window yeah right right well I guess it would be at one side of the aircraft too they might have to have some interesting so here is just a definition of the different oops I'm sorry so here is a different the southern border two minutes here you know Waterbury is 2 minutes and 30 seconds Morrisville is 3 minutes Burlington is between 3 minutes 10 and 3 minutes I think that says 20 and then 3 minutes 30 up here Newport Milton and same for St. Almond's Innesburg's and Swan they're going to get a great full eclipse coverage because it's going to be clear so what causes a solar eclipse and again and then why are they so rare so a solar eclipse occurs and it's a very small area so the area that the eclipse occurs in is when the sun when the moon gets between the sun and the earth and you'd think that happened every day but it doesn't and we're going to talk about the reasons for that but when you have a full solar eclipse you're basically in this thing called the Umbra and the Umbra is the shadow from the moon that's that very small point right there the sun's over here it's a great big ball it's shining light and you get this darkened space and that's why it's only 115 miles wide and then this lighter shaded area sorry I'm so shaky you're a tough audience I'm shaking so this lighter shaded area here is called the Penumbra and that's where you would see a partial eclipse so you can see the area of the partial eclipse is much much larger than the area for the total eclipse the total eclipse area is very small this 110 miles stripe that this giant round shadow is flying across the United States at you know between 1500 and 4000 miles an hour but almost the entire continental USA or North America is going to see a partial eclipse that that Penumbra is very large so an annular eclipse an annular eclipse so this is down here this is the one I got to see in El Dorado, Texas this occurs so the moon besides having to be in the exact position between the sun and the earth it also has to be at the right distance to get a total solar eclipse so you've heard of the super moons the super moons are when the moon is just a little bit closer to the earth so it varies it's not a perfectly circular orbit around the earth it varies between 220 approximately and 250,000 miles when it's at 220,000 miles and it's not a new moon it's during the evening you get these things called super moons they call them super moons because it's a little closer it's very hard to perceive that it's actually bigger at least for me it is and then you might get a micro moon when it's at the 250,000 mile distance and you get a full moon in the evening the eclipses of course occur during the day so we have to have that super moon at 220,000 miles so it will completely cover the sun during our day and when it doesn't when it's a little farther away you get these things called annular eclipses so this is when everything lines up perfectly but the moon's farther away so it's a little smaller from our perspective because it's farther from us it's closer to the sun it doesn't shade the entire sun and you get this I can tell you when you get this you have to keep your glasses on the entire time you can never take them off because even when you only have when you have so much of the sun covered it's still it might be a little dimmer outside a little less bright but it doesn't look like nighttime not even close so it's still very bright out so it would be very dangerous to look at the sun during an annular it was still fun to see it it was fun to photograph it it was fun to travel out there we were on a ranch for that so we were on a ranch in the middle of old oil fields like done pumping oil fields on a on a ranch that does astronomy activity so it was fun so here's a little more detail of the mechanics of why we don't get this alignment all the time so there are various angles here I'm sure people know that the earth is tilted it has an axis that's inclined from the sun so it's not on the same in other words the axis of the earth is perpendicular to the path around the sun it's a little inclined so we're at a tilt that's why we get seasons and I won't go into a lot of that but that's why we're tilted more towards the sun or more strongly towards North America in our summers and more strongly focused towards the southern hemisphere in our winters so that's why we get the seasons so the moon is also tilted from us so the moon has an orbit around the earth that is tilted and not in the same plane as the sun so when the moon is on the side of the sun between the sun and the earth sometimes it's too high because its orbit is not parallel to the path exactly between the path between the sun and the earth and at other times it's too low but there are two nodes in these orbits where the mechanics line up and the moon can be in the right place to cause an eclipse now it might not cause a total eclipse because you know if it's too far from the earth you'll get an annular eclipse but if it's in that right position if it's close enough you know the 220,000 mile point and in one of these two nodes in the orbit we can end up with a total solar eclipse unfortunately it doesn't land in the same place every time it happens all over the earth and we're going to talk about just real fast here we have a couple of props and this is one of one of our members Jim's wife made this it's a giant ball of yarn and this represents the earth and Jack has a smaller ball and from a scale perspective that represents the moon and we have a string then how far away oh yeah how far scale scale wise at the scale how far do you think it should be anybody somebody said 20 feet you hold this isn't that cool yes it would be so cool but the moon goes in an orbit that goes up and down so it has to line up perfectly thanks Jack the sun would be directly straighter than the moon but the moon goes in an orbit that goes up and down so it has to line up perfectly and the sun would be directly straight across from the string so oh my gosh it would be a ways away so when we were in Milton this morning it would have been at the dam so I don't know exactly how far that is so a mile and a half is good so we talked about this earlier 865,000 miles across we talked about the Umbra and Penumbra and the alignment needed the orbital mechanics needed for the shadow to create a full eclipse on the earth's surface and that eclipse area is pretty small if you can see the difference in the shadow there it's pretty close it's a little hard to see it goes out over the ocean and my understanding is it ends on the ocean it doesn't hit another continent so it goes another I forget how many 1500 miles or so over into the ocean the Atlantic ocean and then stops so they don't I guess they don't go on for across the entire globe oh of course you're not going to see it of course so here's just another picture and what it says here is the Umbra that's the totality shadow is never more than 167 miles wide in this case we're getting 115 mile wide shadow and I assume that's a factor with the orbital mechanics and how far the moon actually is away so maybe at the optimal position for us we would get a 167 mile wide shadow so it travels very fast when it's entering Mexico it's going to be 1500 miles an hour entering Burlington it's moving at about 2500 miles an hour leaving Vermont it's 28 100 miles an hour and I want to say somewhere I guess it's not on the chart it was going to be leaving North America at about 4500 miles an hour and it's accelerating as it goes across the continent and here's a and this is an interesting fact I didn't know until this morning either and that is the eclipses follow similar patterns and they repeat so if you look here at the 2027 and the 2009 have very similar path shapes if you will they're just not in exactly the same place on the planet because the alignment of the earth at the time of the eclipses is a little different than it was for instance 2009 2027 so you see them repeating all over you see the 2010 eclipse here and it's going to happen again same shape 2028 over Australia that might have to be where I am but we're going to have clear skies and I'm not going to worry about that so so and I think the 2024 and then the 2016 here so anyway I thought that was very interesting that they have that same I guess it makes sense given the orbital mechanics are the same it's just the earth is in a different spot the earth rotation is a different spot when that moon alignment occurs on different years thank you you're right yep what do they call this kind of projection mercader projection thank you I thought that was interesting there must be at least two per year but there are no more than five and we get similar solar and lunar eclipses they repeat a bit more than 18 years and there's called a serocycle and two eclipses separated by one serocycle are similar and I think that pertains to the chart I just showed you see similar occurrences of that same shape of the eclipse path so this is the thing I also found interesting is this next fact you know the fact that eclipses actually a total eclipse is going over burling over Vermont in our area is quite rare on average it only happens once every 375 years it goes over the same spot on the earth now it can happen a lot closer together in fact you'll see in a minute very close together and actually happened in a place in the United States or in North America recently where two eclipses occurred two total eclipses occurred seven years apart which was a rarity compared to the average of 375 years our next partial eclipse is in 2026 boring we're going to have a nice one here and then the next total eclipse is going to happen on the continental US in 2045 that's another 20 some years so I hope we're going to have clears guys so where to look where you need to look to the southwest so the preceding partial phase will be halfway up the sky it'll be high so the sun is at a higher point at about 49 degrees totality will be a little lower about 40 degrees so you want to have a place where you can see when it starts you want to have some room so you don't want to have the treeline right below the sun when it starts because that means when it hits totality you're not going to see it so get to a place where there's some you can see at least down to the finish partial phase 30 degrees that's not that you know that's not that difficult to find so and at a minimum you want to be able to see 40 degrees because you want to see that full total eclipse and so what to expect on April 8th so it'll slightly it'll slowly dim and I can tell you for partials it's very hard to tell it'll dim a little bit but you'll have a sensation and maybe a thin cloud gone over or something but my understanding is when it hits full it's like turning off the light switch and it's turning off the light switch on not entirely dark it's not going to be like night time but it's going to be maybe like a half an hour after sunset or something so it's going to go off pretty quick you'll feel it change in temperature of course heating is basically turned off and animals will probably be acting like they do at sunset you know birds will be going to roost you know they're heading for the trees to bed down for the night so I guess it's an interesting thing to experience I hope we will on April 8th experience that so here's just a picture of a bunch of pictures actually taken of the eclipse and hitting totality here and you can see the nice the nice corona and then heading off so the moon's actually traveling in terms of relative the moon's traveling everything is traveling west of course you know the moon and the sun everything travels west across the sky because we're spinning in the opposite direction we're spinning counterclockwise as an earth but the moon is relative to the sun is traveling this way you know traveling east relative to the position of the sun and that's why it's leaving the west side here and here's a photo a set of photos a collage of photos done by one of our members for the 2017 eclipse and here's something called Bailey's Beads and I'm running out tell me if I'm in trouble for time okay alright okay alright so we're almost done so this is called Bailey's Beads so you know the surface of the moon isn't entirely flat there are mountain ranges there are lots of craters so that gives you a features on the like a surface feature features on the moon so when the sun gets to the point or the moon gets to the point where it's basically eclipsing the sun in some places it will eclipse it in some places not it's like peeking through the trees as it gets to the final edge because there are mountain ranges and crater ridges and that and when that sun peeks through those places like peeking through a fence or through the trees it creates these things called Bailey's Beads and this was the gentleman that I guess named those that that phenomena back in in the 1770s to 1800s and here's a picture of something called the diamond ring effect so this is when the sun this happens twice during a total eclipse it happens once when the sun first first starts to cover is almost completely covering when the moon almost completely covers the sun you get that last glint of full sunlight this is before actually Bailey's Beads Bailey's Beads are kind of at the very end so they call this the diamond ring and then you get the full this is totality so you get this you can see the corona and like I said this will go out one, two, I don't know three or so diameters of the sun out from the sun so it's quite a spectacular effect here's another picture and this is from one of our VAS members from 2017 so this is a quick picture so it's not nighttime in this picture this is actually the map of the sky during the day it's just black for purposes of seeing but somewhere on here is the sun and it's going to be black because it's covered oh it's right here so we get the sun here we've got Venus here and Jupiter here we think when we're having the full eclipse you'll actually see those two planets you'll be able to see Jupiter and Venus because they're both you know Venus is the brightest planet and Jupiter would be the next brightest planet we think you're going to see both of those there's also a small chance you could see a comet there's a comet up here and I can't see it from where I'm standing but it's Ponsbrooks it's 12p Ponsbrooks there's a chance if it brightens up some we might actually see a comet also so it's very cool but don't waste your time looking for it if it isn't obvious enjoy the full eclipse so safe solar viewing never look at the sun directly without solar glasses you can look at it indirectly by projection any pinhole I talked about this earlier you can use household utensils all kinds of things to make pinholes here's one just some holes punched into a piece of cardboard and shined onto a white piece of paper here's one that Jack did I think for the 2017 eclipse partial eclipse and you know we're punching out VAS and little pinholes and getting them projected on a piece of paper people were doing that in El Dorado it was fun people were working around with those things anything that will make a pinhole projection will do that so another example through trees as well you know if you get gaps between the leaves in a tree I don't know if we're going to have any leaves in April but that would if it was later in the year you would see that those are very cool people can make these pinhole boxes there's all kinds of ways to do this to view the eclipse indirectly so you're not looking directly at it a safer even safer than using glasses of course you can have your head in a box there's different ways to do it you know the last one just had a hole offset over here and looking from the outside but you can do it from the inside too just don't just don't climb any stairs while looking at the eclipse with the box on your head and of course safety solar glasses and the thing about the solar glasses whoops they should have an ISO rating on them so when they're good solar glasses they have an ISO rating on them and we have the numbers in the presentation they're also on our eclipse viewers those ISO ratings you want to make sure they're rated here's a picture of things that people can use we do not recommend using these welders glasses my understanding they don't protect against a certain kind of radiation I think it's UV radiation and so we don't recommend those all of these other things are safe as long as they have the ISO rating again we don't recommend welders glasses here's a picture of the VAS viewers and you know again the partials both coming and going you have to wear the glasses or use an indirect use the box and then the fold you take the glasses off and typically during eclipses there will be a caller I'll be doing that in Williston on the Williston green I'll be calling out glasses on, glasses off somebody should be doing that and timing it because you don't want to end up looking at the sun when it peaks peaks back through and here's the ISO rating so don't use ordinary sunglasses you know anything that doesn't have that ISO rating not smoked not smoked glass not photographic or X-ray film no space blank at the padded just DVDs, aluminum foils none of those are safe and not welders glass and here's just a picture of a bunch of people looking at a partial solar eclipse and again they've got you put the the filters on the front of any magnifying optics that's important glasses on, don't put eclipsed glasses on and then look through a pair of binoculars because that light will be focused by the binoculars it will burn a hole into that film and you will hurt your eyes terribly so it always has to be before the optics so on the front of a telescope on the front of a pair of binoculars not on the back end that would not protect you that light is very strong when it's magnified even a little bit I'm sure as kids you've all taken the magnifying glass with light and on a leaf and it burns it quickly and here's a telescope with a filter on it and that's that's it so I'm sorry I went long I guess I'm a long talker any questions? oh they're both dangerous I mean they're both it is damaging to your eyes but at the end of the eclipse so at the end of totality your pupils are going to be a little dilated they're going to be bigger so when that light first peeks out and is very bright that would be more damaging than when your pupils are very small oh go ahead you know more don't look at the sun at any time without some protection yes well we don't have that but you can just go to the eclipse 2024.org website that you can actually look up Vermont for the timing, the direction and of course you'll see it's going to be clear so you're welcome it'll be clear so you'll see the sun rising so and you'll I believe it's the partial starts around I forget now around two something so yes they're absolutely it's called the eclipse timer yeah it's the eclipse timer and it's a great app and I'm actually going to use it because it actually it calls out announcements from your phone so you basically start the app you put it down and it does audio cues it says you know glasses on glasses off yes so the eclipse timer yes I imagine it would be if they're in the path I don't know if they're in the path it's going farther north after Vermont so I don't think they would be in the path be in the path of totality yeah oh yeah yeah they open pretty frequently too yeah those are interesting that's when the moon turns basically red yeah that's very cool the pictures of those never the total yep absolutely if you go out a week or five days or seven days ahead that's the approximate position so you're going to know where the sun is at the time of the eclipse just make sure it's clear and make sure you get that view from the start to the finish of the eclipse yes won't change much in a week it's on android and apple well it depends so during totality no filters needed you can take pictures the brightness of the corona is only about the brightness of a full moon so it's you can easily take pictures of the moon as you know but during partial you absolutely need filters you should use a filter yeah are we we're going to have a session on April 1st a week before you know we meet the Monday the first Monday of every month in this case April 1st is on a Monday we're going to be talking about eclipse photography and viewing the eclipse and what we're going to be doing on that date so that would be a date to call in I don't think we have any practice sessions but there's a lot of YouTube videos out there to give you an idea of what to do so are you talking about with a lens SLR with an iPhone oh yeah so for photographing the eclipse something between if you have a telescope something a little wide angle because you want to get at least three diameters of the sun away from the sun for the entire corona if you want to get the whole thing so I've seen recommendations four five six seven hundred millimeters but not much more than that for a telescope so four hundred would be perfect it sounds yeah and if you can plug an SLR into the back yeah if you can practice ahead of time so and my understanding is the is the filtered so this is uh depends on the filter you're using if you're going to take pictures before you'll need a filter on your scope because you don't you know you'll cook something because you're magnifying the light the exposure through the filter is about the same as the exposure for the corona afterwards so when you have totality it's about the same as the filtered light that's going to depend on your filter I just had seen that recently so I will have to see my exposure at ISO 100 for the partial through the filter was one eight hundredths of a second at f7 my scope was at f7 so if that gives you any idea yeah I think you would see it you would fly through the if you flew through the shadow you would have to fly under the shadow the path is only activated when the shadow goes over it it's going over it very fast you would have to fly over the exact intersection of the shadow moving across that path oh you would of course yes well you need solar filters so you can get them from b&h photo amazon sells them b&h photo vagina, astro many places and that's a popular thing yeah thank you everybody