I Observed Legendary Galaxies First Discovered by Sir William Herschel over 240 years ago

本站添加: 2026-05-12

[00:00:00]So, this video is sponsored by PiFinder, the Sir William Herschel of a finder scope. Now, some 240 years ago, Sir William Herschel, probably the greatest observational astronomer of all time, he discovered 74 galaxies in one night with one sweep of his telescope. Galaxies had never been seen before.

[00:00:20]And what we're going to do tonight is I'm going to show you three of the most attractive and scientifically interesting galaxies from his night of discovery. So, hopefully by the time it's getting dark, this wind will have dropped down, but we do have a first quarter moon to battle with.

[00:00:35]Now, unlike Sir William Herschel and his antique telescope, we've got a modern telescope, we've got high reflective optics, we've got a mount with go-to and tracking, we've got plate solving through the PiFinder so we can find the objects we want to look at, and I'm going to share the views with you by using the camera, put a camera in the focuser, and I can share the views with you by using the SharpCap live stacking. So, we'll take a series of exposures with the camera, and the software will automatically stack them up and build up that signal.

[00:01:04]So, it's still dusk, it's still not quite dark yet, we've still got some blue skies. What I'm going to do then while we get set up is I'm going to swing across to Jupiter.

[00:01:24]So, we've got Jupiter in the field of view. What I need to do then is just check the focus, we'll get it nicely lined up.

[00:01:34]So, I'm just focusing on the moons, that's all I'm doing, just making sure the moons are as small and as sharp as I can get them.

[00:01:40]So, what I'll do now is I'm going to reduce the field of view, get the field of view just so that it covers the the planet itself, and then we'll do the planetary live stack, and we'll be able to stack.

[00:01:51]The software will reject all the blurry frames, it will then stack the sharp ones, and then we can just keep the good ones, We'll see a nice view of Jupiter.

[00:01:59]Now, I'm not using my planetary imaging setup. This hasn't got the Barlows and the atmospheric dispersion corrector, but it's still going to be a much better view than we can see just on the camera screen.

[00:02:17]All right, so I've got Jupiter centered.

[00:02:18]It looks pretty well focused to me.

[00:02:20]Let's try and do some live stacking then.

[00:02:23]Click on the planet.

[00:02:26]Nothing. And all I do is I hit auto sharpen.

[00:02:30]And Oh, there we go.

[00:02:32]Oh, there's something.

[00:02:35]There's a little shadow. Hold on. Let's have a look then. Let's go to Sky Safari then. Sky Safari. This is my planetarium software, the Sky Safari.

[00:02:43]Oh, wow.

[00:02:45]We've actually got the moon Io casting its shadow on Jupiter.

[00:02:51]I can't see the moon.

[00:02:53]Let me go a bit bigger.

[00:02:57]Can't quite see the moon, but you can actually see the shadow. The shadow alongside the cloud belts. Isn't that amazing?

[00:03:04]Oh, that's a really good fun bit of luck. Just by chance then, we set the telescope up in time to see a shadow transit.

[00:03:12]So, I've been leaving the telescope just to run for a little while, but unbelievably I can just start to see Io pulling away.

[00:03:20]The actual moon itself is pulling away from uh from Jupiter as well. So, I've actually got the shadow on the surface.

[00:03:27]You can just about start to see Io moving away from the limb. How cool is this? What a shame I haven't got the planetary camera setup with a Barlow and the atmospheric dispersion corrector.

[00:03:38]This is all set up for deep sky live stacking, so I haven't got the high resolution stuff in, but oh, that would be amazing.

[00:03:45]That's a stunning view. Look at this.

[00:03:47]We've actually got the moon now. It's properly separating away from the limb now. It's a few minutes after it's cleared the limb. There's now a a proper black channel between the limb of Jupiter and the moon.

[00:03:58]You can actually see it still casting its shadow on the cloud tops. Oh, wow. And that's just totally by chance. I didn't know this was going to happen.

[00:04:06]Fantastic.

[00:04:08]That is absolutely amazing.

[00:04:11]Right, so it's probably getting dark enough. I'm going to go and try and see if we can find our first galaxy.

[00:04:16]Right, so I need to go and check my focus. I thought the focus would still be pretty good having just looked at Jupiter, but I need to just go and check that. So, I'm going to go and find a star, the nebula.

[00:04:36]There we are. So, there's the nebula on the screen. There we are.

[00:04:41]Right, so what I've got to do now then is put the battlement mask over the top of the telescope. And that gives us this really nice sort of butterfly-shaped image. We can then use that to fine-tune the focus.

[00:04:56]So, I'm trying to get this I'm trying to get this little butterfly pattern as symmetrical as we can. I think I'm just about there.

[00:05:06]It's obviously getting quite hazy up there.

[00:05:13]Let's do one more small tweak.

[00:05:20]Cool. Okay, I'm happy with that.

[00:05:22]Uh what I'll do then is you've always got to remember to take your battlement mask off. Don't carry on with that on the telescope.

[00:05:36]There we go. We've got some really nice sharp stars.

[00:05:41]But one thing William Herschel would have enjoyed is a pine finder. Now, if he's is to use the star patterns to work out where the telescope is pointing.

[00:05:50]Now, unlike Herschel, I can type in what I want to observe and the PiFinder will give me the directions to go and find it. And I must say this makes finding objects such a pleasure. And best of all, it has Wi-Fi, so I can link it to my iPad and I can use SkySafari to show where the telescope is pointing. Now, if you are interested in a PiFinder, then use the code Refreshing Views at the checkout on the online shop and that will save you 10% off your order.

[00:06:17]>> [snorts] >> So, what I've done, I've got the PiFinder switched on and I've linked it up to SkySafari.

[00:06:26]And what I've done is I then set the field of view so it's the same as that chip. So, it's a 0.3° field of view.

[00:06:33]Obviously, it's a big telescope, long focal length. Even with a focal reducer, I'm not getting a really wide field of view.

[00:06:40]But, I've got it all set up and it can then chart where we are in real time as the telescope moves across the sky. So, the other thing I've done on SkySafari is I've actually imported the sweep all the objects that Herschel discovered on there. So, I can actually see that. We can work our way or work our way on to the three highlights. I do love that, being able to see that planetarium style display. So, what I find incredible about this is that Herschel did his sweep, he discovered 74 galaxies all in one night. And he did this from the UK, which as you know, in the winter it's too wet and rainy, it's too cloudy and in the summer when the weather is nicer, it doesn't really get dark. I mean, it's nearly Yeah, nearly 10:00 and it's still pretty much late twilight, late dusk. You know, stars are just starting to appear. So, how on earth he sort of founded observational astronomy, the sort of science of observational astronomy from the UK where the weather's either too wet and cloudy or it's too bright and sunny, too light in the evenings. Yet, he did that from the UK. So, I've got everything set up. Then, We've got SharpCap set up here. We've got the PiFinder showing where the telescope is pointing. Now, SharpCap, when it does its plate solving with the telescope in Alt-Azimuth mode, when it's set up like this, left and right, doesn't do the tracking, doesn't do the go-to, doesn't do the tracking very well. So, I'm going to actually just use the ordinary hand controller or we'll use the app rather than the hand controller. So, I'm going to use the PiFinder to just fine-tune and get us properly centered.

[00:08:08]So, our first target is NGC 3561, which I'm sure is a very familiar target.

[00:08:15]And let's go into here then. Where are we? So, first target NGC 3561.

[00:08:25]3561.

[00:08:28]Go-to.

[00:08:33]Always just keep an eye on cables.

[00:08:36]Just in case.

[00:08:40]There you go. So, now the PiFinder has done its plate solving and now knows where it's pointing. Let's zoom in.

[00:08:45]So, now I know where the telescope's pointing. I actually know where its position is from the planetarium software.

[00:08:51]I can then work out the corrections I need to do to get that centered in the field of view. So, we need to get up and left.

[00:09:02]There we go. Pretty much in the field of view. 3561. Set target name.

[00:09:10]Let's bring up the black.

[00:09:13]Boost the signal.

[00:09:17]Balance the colors.

[00:09:20]Look at that. And this is actually This is what I find quite amazing. This whole region here is actually a galaxy cluster. This is one of the Arp galaxy clusters. It's a beautiful um Yeah, what what at first appears to be just full of stars is actually full of galaxies.

[00:09:38]That's actually incredible, isn't it?

[00:09:40]And then this is our faint interacting galaxy here. Just look at that.

[00:09:46]That is stunning.

[00:09:50]And with the bright moon lighting up that thin cirrus cloud, we're not picking out the faint details, not the faint details that I want you to see.

[00:09:57]So, what I'm actually going to do is switch back to an earlier picture I took earlier in the week. This is such a stunning object, and when you look at it, you've got this galaxies, these two galaxies that are sort of tightly interacting, and they're sort of passing by each other, and they're drawing this material from one galaxy away to the other.

[00:10:15]That's what I find incredible about this amateur astronomy is not only have we just seen Jupiter cast it Sorry, I just seen the moon of Jupiter, Io, casting its shadow onto the cloud tops. We've now got this galaxy, these two galaxies interacting with each other, drawing material from one to the other.

[00:10:32]Gosh, incredible, isn't it?

[00:10:34]And that's with the moon only a few degrees away, as well.

[00:10:41]This live stacking really does turn what is a, you know, a relatively small unit.

[00:10:46]It's not the biggest amateur telescope, but by using the power of the camera, you can really pick out all of these sort of faint details that you just simply cannot see with the eye. There, your eye can't do these long exposures, stack the image up.

[00:11:01]So, we're sort of coming up to What's that? 5 minutes, nearly 6 minutes of deep data now, which is in imaging terms is next to nothing. And so, we've got the two galaxies there, 3561A and B.

[00:11:14]And then that's the tidal tail up there.

[00:11:16]That's where the material's being drawn in.

[00:11:18]That's looking some 10° away from the moon. The moon's only just round the corner.

[00:11:24]Look at how many galaxies we've got in the field of view.

[00:11:29]That's amazing, isn't it?

[00:11:32]So, our next galaxy is actually quite a cool grouping of four galaxies.

[00:11:37]NGC 4169 There's the numbers and we'll do a quick go to deep sky.

[00:11:48]4169 go to So, we're a little bit off. We've got to go up and left.

[00:12:14]Here they come.

[00:12:17]Oh, it's so cool being able to see it on the screen.

[00:12:23]All right, let's see what we've got in the field of view then.

[00:12:31]All right, so our colors So, there we have it. We've got four galaxies. 1 2 3 4. They actually form this box shape this rectangle shape.

[00:12:47]Now, I first saw this in the winter star party and Jim Jim, the guy with the the big telescope she showed me these the view absolutely stunning. So, being able to see this visually is quite cool as well as being able to see it on the with the camera.

[00:13:02]If I remember rightly, there was three galaxies. The smaller three are actually much further away.

[00:13:08]And the fainter galaxy up here is actually a smaller galaxy, but it's much closer to us than the other three, but it's still pretty cool.

[00:13:15]You have to see four galaxies in the field of view, three of which are gravitationally bound together.

[00:13:25]So, what we're going to do for our third object is go the Coma Galaxy Cluster.

[00:13:28]Now, this is one of the densest, richest galaxy clusters, I think, in the observable universe. It's hugely dense.

[00:13:35]It's actually got over a thousand members, a thousand galaxies gravitationally bound together. Now, Herschel, when he did his sweep across, he found the brightest three, two of which are what we call super elliptical galaxies. They're far bigger than the Milky Way, several times bigger than the Milky Way. That's what Herschel discovered when he did his sweep across.

[00:13:57]So, I need to use the pie finder again.

[00:13:59]I'm going to use NGC 487 2. Get you set up. That now gives me my left, right, up, down arrows. So, I still have to swing to the left and go down a little bit.

[00:14:11]We'll go NGC 4872.

[00:14:21]And you see the numbers changing. You probably can't see that now.

[00:14:26]We can see when I get Oh, look at that.

[00:14:28]How many galaxies are in the field of view?

[00:14:32]And then we've got to go smidge and right a smidge.

[00:14:39]Gosh, you can see that for how many galaxies there are.

[00:14:46]Give that a little boost. Oh, look at all those galaxies.

[00:14:57]Oh, wow.

[00:15:08]So many galaxies in the field of view.

[00:15:11]Oh my goodness.

[00:15:16]Goodness me.

[00:15:28]>> It's incredible how many galaxies are in this field of view.

[00:15:32]What appears to be just a a star field is actually a galaxy field.

[00:15:37]Um the NGC the plate solving button will only find the brighter NGC galaxies. I haven't loaded up the fainter Oh, so I just knocked something over. I haven't uh I've loaded up the galaxies. There's actually far more fainter galaxies in the background you can see there.

[00:15:54]Absolutely stunning.

[00:15:57]And we've got the super elliptical We've got the super elliptical galaxies as well, the ones that Herschel himself discovered when he did his sweep across this part of the sky.

[00:16:08]So, one of the things I did earlier in the week was use the small telescope, the little refractor, the Megrez 90. I actually captured some live stack of the uh of the Coma galaxy cluster. The big telescope, the C11, even with the F6 focal reducer, it's actually a very small field of view um even with that focal reducer in. So, being able to switch across to the Megrez although you didn't get that resolution, those fine details uh being able to use the refracting they give us a far far greater field of view. And of course there wasn't a massively bright moon in the sky at the same time.

[00:16:41]Oh, that is stunning. Well, even though we've had a bright moon, we've had a few patches of cirrus getting in the way, we actually had quite a good fun night uh using the telescope, using the power of the SharpCap. You realize how great an astronomer Herschel was. You know, he discovered 70 more galaxies in the field of view. Even with all the equipment I've got, a camera with a PyFinder with the SharpCap live stacking, these objects aren't easy to find and yet there he was sweeping them up, the very first person to ever see these sights and to discover them and record them for science. So, what a You realize what how capable he was, how competent he was as an astronomer.

[00:17:23]So, I hope you've enjoyed that video being able to see those galaxy clusters, seeing these highlights from William Herschel's sweep. What's that?

[00:17:30]200-something years ago. Well, thanks to PiFinder.

[00:17:34]Thanks for your support and sponsorship of that video. Do check out their store if you want the electronic finder. 10% off if you use the Refreshing Views discount code. Well, thanks once again to the patrons. Thank you for your continued support and I wish you clear and steady skies.