Messier Objects - Deep Sky Videos

Hi everyone, this is a formal introduction to deep sky videos and I thought what better place than sunset on top of a volcano. I'm here at La Palma and that's the Isaac Newton telescope behind me. In fact they're opening it right now as we speak to start looking at the deep sky. Now throughout this series we're going to make a bunch of videos all about astronomy, telescopes, things in the deep sky, in the depths of space, but the main thing we're going to do is a series of videos about the so-called Messier objects. That's 110 different objects in space. Now first of all we should tell you what the Messier catalogue is and who was Charles Messier, but I'm not going to do that. I'm going to leave that to the astronomers. Charles Messier, an 18th century astronomer who was sort of one of the founding fathers of the subject in the sense that he was one of the first people who actually went out there and catalogued things in the sky in a reasonably systematic manner and things that further away, you know, people since the ancient Greeks had been looking at patterns of stars, but he was looking for things that were fuzzy, things that were further away and in some sense more interesting than just the pattern of dots on the sky. He was a comet hunter. The king of France called him the ferret of comets. He ferreted out lots of comets I suppose and so his business was scanning the skies in a systematic manner trying to find comets which were transitory nebulous fuzzy objects that appeared in the sky and got brighter and became quite spectacular and he was very good at this. So nowadays he's most famous for this thing called the Messier catalogue which is just during the course of his life he just kept a list of fuzzy things he found in the sky and wrote them down in no particular order, he just wrote them down in the order that he found them. So M1, Messier 1 is the first object that he happened across. He found himself frustrated repeatedly by getting excited by things that appeared to be comets, they were fuzzy, they had the look of comets in the sky, but actually weren't. So to save himself and everyone else frustration he compiled a list of objects that weren't comets. They're actually still very popular targets there, you know the telescopes Messier was using were small enough that actually they're about the equivalent of a very small amateur telescope today. So the objects he was seeing is accessible to absolutely anyone, you know the professionals look at them because they're the nearest brightest examples of things, but amateurs can look at them because they're actually still close enough that they can see them with a pretty small telescope. And he numbered these 1 through 45 in his original catalogue, although that's grown to the official catalogue of 110 now, and we refer to those objects as Messier objects. Or we just refer to them as M1, M4, whatever, it's a shorthand way of referring to the Messier number. A lot of the things that happened in his life were just down to coincidences, things that just happened during the course of his life and that was the path he ended up following, which is why he ended up producing this catalogue. I guess most people's lives are like that to a greater or lesser extent, but he seems to have more coincidences in his life than most. He started his career working as an assistant at the observatory in Paris and was put to do various tasks by his boss, one of the first of which was to plot the locations of comets, and in particular there'd been a prediction that Halley's comet ought to be coming back again, and so he was given the task of trying to find it again, so he was using these telescopes to try and find Halley's comet. Coincidentally, his boss had given him the wrong place to look in the sky, because his boss had done the calculations a bit wrong, and so he was looking in the wrong place, so there was no way he was going to find Halley's comet. But again, coincidentally, he found another comet while he was looking there, and then of course he then started tracking this comet as it moved across the sky, and during the course of those observations this comet just happened to track past one of these fuzzy objects, the thing we now know as the Crab Nebula, and it was the first one that Messier looked at and thought, well there's another fuzzy object, but then it wasn't moving, and so that was the first object where he thought about, well maybe I should start keeping a record of these other things which aren't comets, so I don't get confused. So again, it was really a series of coincidences that led to him coming up with the first of these objects, the one we now call M1, because it's the first one in his catalogue, that led into this whole cataloguing exercise. Messier's criteria was it had to be something that you might confuse with a comet, so it has to be fairly faint, fairly fuzzy, but the main primary difference from comets is that they don't move. Comets actually track across the sky as the comet orbits around the solar system, these objects don't, so it's basically anything that's fuzzy and doesn't move relative to the other stars. So this includes planetary nebula, diffuse nebula, supernova remnants, open clusters of stars, globular clusters of stars, and then outside our own galaxy, though that certainly wasn't known at the time of Messier, other galaxies external to our own. So it's this wide array of different objects that all get put together as things that you might confuse for a comet. Well, he certainly lives on in history because of this list, but it's kind of ironic that it's a list that's famous not for his intended purpose. These are the objects he wasn't interested in, where in fact for most astronomers now, though comets are of course interesting in their own right, they're certainly of not the same degree of complexity and intensity of these really exotic objects that are compiled in his catalogue. They're special in that because they're the ones that are most obvious, they tend to be the closest examples of whatever the phenomenon is, whether it's another galaxy, or whether it's a cluster of stars, or whether it's a planetary nebula. So in that sense there's nothing special about them, there are many other examples of galaxies and star clusters and planetary nebulae, but if you're going to study these things it makes sense to pick the closest ones because you get better pictures of them, you can see them more clearly, you get more right for them, so you can just study them in a much more detail. So in that sense they're still important and people still colloquially, even in professional astronomy, tend to refer to Messier objects by their Messier number rather than any other name. So I guess the one that I've studied most in my career is M31, which is also better known as the Andromeda galaxy. It's sort of close to being a twin of the Milky Way and so it's sort of studied a great deal by people who are interested in spiral galaxies because it's the closest example of a bright spiral galaxy that we're not kind of stuck in the middle of, so you can actually get a good picture of it. And I've done a number of studies of the Andromeda galaxy, looking at what's going on in its very centre, looking at the distribution of stars in it, looking how fast it's rotating, all those kinds of things, just because it's a good example of a spiral galaxy to study. Unlike some of my colleagues I haven't actually worked on any of the Messier objects. I work on galaxies but not galaxies quite this nearby, but certainly just in the sense that some of these objects are iconic astronomical images that almost certainly influenced my passion for astronomy. So we'll talk about the Eagle Nebula, which is a very famous image from the Hubble Space Telescope. M13 is a globular cluster that I remember as an undergraduate demonstrating astronomy observing labs in the depths of the Canadian winter, standing out in frozen fields. I want to make a video about all 110 Messier objects. I want to make 110 videos. I know you've agreed to help me. Is this a stupid thing to do? No, it's not. I mean, you know, it's 110 videos, it's going to be quite a lot of work, but, you know, there's something to say about everything. That's one of the nice things about them is that there's always something exciting going on in each individual object as well. So yeah, I think there's certainly potential for making videos about all 110.