Star Diary: 14 to 20 August, 2023
What’s in the night sky in the week of 14 to 20 August, 2023 in our weekly stargazing guide. This week’s new moon makes it a great opportunity for some deep-sky observing.
Chris Bramley: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the print edition of the magazine by visiting skyatnightmagazine.com or to our digital edition by visiting iTunes or Google Play.
Ezzy Pearson: Greetings listeners and welcome to Star Diary, a weekly guide to the best things to see in the Northern Hemisphere’s night sky. As we are based here in the UK, all times are in BST. In this episode, we’ll be covering the coming week from 14 to 20 August. I’m Features Editor Ezzy Pearson, and I’m joined this week by Reviews Editor Paul Money. Hello Paul.
Paul Money: Hello Ezzy. Back to another week, but not many actual events this time, but there’s still lots to look out for, isn’t there?
Ezzy: Absolutely. So what do we have to look forward to in this week’s night sky?
Paul: Well, the key is, as new Moon occurs on 16th, so roughly middle of the week – sort of middle of the week – this is the first proper dark set of nights after the summer light skies. So deep sky observers and astrophotographers will delight in this week, and we’ll be hoping that we have clear skies. You know, can’t we? We can always hope about this sort of thing. So this is a good time to explore the Milky Way because it’s straddling the sky. It’s actually going from the northeast roughly right across the sky, and then dropping down towards the south and the south east sort of thing. So it’s a great time to look at the Milky Way. And there are lots to see along the Milky Way. And when we’ve got star clusters, we’ve got nebulae sort of thing, we’ve got things like globular clusters as well. We’ve got the dark rift in Cygnus, so we’ve got darker. A lot of people tend to forget that you can actually see dark clouds of dust, but the key is to see there’s got to be a background to it. So lots of stars because of the Milky Way, so any dust in front of that will block the light of the stars, so it’ll look darker. This is where we get this gap, naked eye, running through Cygnus, called the Cygnus Rift, and if you look on a really dark night sort of thing, you’ve got no light pollution – this is another key, no light pollution, then you should see this splitting of the Milky Way, and it’s not splitting, it’s just that there’s this great cloud of dust. So this is a great time to look at these sort of dark clouds, and especially one in Cygnus, because it looks like the Milky Way splits, but it doesn’t. It’s this great cloud of dust that’s sitting in between us and the rest of the galactic disk that gives this impression that it splits, but it’s actually a great cloud of dust. So yes, I always think it’s quite funny saying you can actually see a dark object at night.
Ezzy: Yes. I always think it’s, it’s one of those things that… the thing that makes the Milky Way so interesting is the fact that it does have these bits that you can’t see. And it’s, it makes it sort of into something that’s patchy with lots of interesting features into it rather than just this sort of plain band going across the night sky. And also because, you know, I come from a space science background and like astrophysics, it’s really interesting to see that, you know, there’s this, all this dust in the night sky, as much as that did, causes people a lot of problems when you’re trying to, you know, look in towards the galactic core or into the depths of the Universe, the fact that there’s all these dust clouds getting in your way. It’s very annoying.
Paul: That’s for the professionals.
Ezzy: It’s very annoying. That’s why you have to go and build a very, like, 10 billion pound… dollar telescope for JWST to try and cut through all of the dust.
Paul: And they did a brilliant job, I mean, and the Hubble as well, to be able to peer through the dust because the infrared penetrates it and allows you to see deep into the heart of the, where stars are being born. This is the key. And they didn’t know this in many times, did they? So they didn’t realise stars are being born inside of these dark clouds as well. So they always thought there were things like the Orion Nebula sort of thing, a bright, gaseous nebula, but you actually need dust as well. In fact, without dust, me and thee wouldn’t be here. And neither would the listeners.
Ezzy: We are all made of star dust, as I believe Carl Sagan said. It’s also that sort of thing, it’s like inside of those dust clouds there’s, you know, really bright young hot stars bursting into life, they’re just, you know, cocooned away, we can’t see them.
Paul: Or like that term, cocooned away. Yes, I like that. They are, they’re hidden away, but no longer with these telescopes we can peer through them. Now, I’ll say we haven’t got many actual events because we’re often reliant on the Moon. Well, we’ve got one, and that the Moon, although it’s gone through New on 16th, it will creep into the evening sky, it crawls back into the evening sky. Again, the ecliptic is shallow, so it takes its time to emerge, so it’ll be a difficult one. But on 18th, you want to be looking just before 9pm in the evening, so it’s one of those things, again, you’ve got to make sure the Sun has set, but look for a very, very, very thin, very slender crescent Moon. You might get a bit of Earthshine, but I think the sky background will be bright, so it makes it quite harder to see, to distinguish between the two, but you should have a little thin crescent. And if you go on just to the left will be Mars. But you’ve got to get them before they set, and they’ll set within about 5-10 minutes. So you’ve got to get them quick. So it’s about 30 minutes after sunset on 18th, and after this, really, Mars does become an extremely difficult object, whereas the Moon will gradually move higher up the ecliptic and become easier to view as well. But that’s for next week sort of thing. But this is a chance to actually spot it next to Mars and probably give you the last chance of seeing Mars itself. Now, I mentioned that once twilight is over and this applies all week, the sky is getting darker. Now, Saturn is over in the southeast. We’re looking at 11 o’clock now and Saturn is well up in the southeast with Neptune in the east-southeast. Jupiter is now rising by 11 o’clock. It’s amazing how quick it catches up with you. You know, lamenting the fact that Jupiter was lost in the bright twilight sort of thing in June, and now suddenly, a month and a half later, it’s back, and in a dark sky, and rising, let’s say, just before 11 o’clock in the evening. So give it a short while later, about half an hour, and Uranus will actually have risen as well. So you’ll have all four gas giant planets to view. And of course, if they’re available to view, they’re available to image as well. You really want them to get higher. And Saturn at the moment will be the best place to view before in actual fact the twilight begins, because it’ll be high up in the south around about 2 AM in the morning. But with it being higher along the ecliptic as well, it’s much better than it was a few years ago when it was languishing down in Sagittarius and very low, and we were looking through a lot of the murk. So we’re beginning to get to the stage whereby we’ve got the planets in a more favourable position to actually photograph and image, and we get some absolutely stunning images sent in from our astrophotographers. You know, it’s just incredible to see the detail on these planets as such. So it’s nice to see them actually coming up. Now the thing about Saturn, and it’s something that a friend’s photograph recently reminded me, the rings are beginning to close up. I forget now when it will be actually edge on, but we can only be two or three years away from that, I would have thought.
Ezzy: We actually have an article about that in our August issue of Sky Night Magazine which is all about how to photograph Saturn before its rings tilt away from view. Next year you will just be able to see the fact that they’re tipped slightly but then I think in 2025 that’s when they’re pretty much going to be edge on. So if you want more details about how to capture them on camera before that happens do pick up the August issue of Sky at Night Magazine.
Paul: So view it now while you can still see the rings. I can remember the last ring plane crossing and it was like, where’s the rings gone? And for a few weeks you could not see any sign of the rings. Amazingly the Hubble telescope was able to pick out this tiny thin pencil lying across Saturn. Just absolutely gorgeous sort of thing but for us pretty average people with ordinary telescopes, it was like, where’s Saturn’s rings gone?
Ezzy: We should point out they will be back as soon as the 2025 is over, we’re moving forward, they will start tipping back the other way as our angle relative to Saturn changes and we can see the other side of the rings.
Paul: It’s very easy to forget, isn’t it, that planets, the other planets, quite often some of them have got their own decent actual tilts. If I remember right, Jupiter hardly any tilt at all, it’s about a degree or so, but Saturn is 26 degrees. And that gives it its seasons as well, but it also means we get this varying view. Just think, from Saturn’s point of view, if we had rings, they’d see something similar. They would see the Earth have rings and they would go through a ring plane crossing as well. That would be interesting.
Ezzy: That would be fun.
Paul: You know what, we’ll have to wait until we’ve got space travel and whatnot. I know it’s a long time in the future. We’ve got a space station in orbit around Titan, and then there’ll be astronomers waiting for the Earth to transit the Sun. That’ll be an event for them.
Ezzy: Yeah.
Paul: You know, it’s something we can’t see, of course. We have to wait for Venus and Mercury, and we won’t be getting Venus now in our lifetime, sort of thing. But at least Mercury, we’ve got a chance, a few years time, so you know, I’ll look forward to that. Finally, we have got the actual minor planet as well. We haven’t just got the gas giant planets in the morning sky, we have got Vesta. And I always think it’s worth trying, I mean, the weather can play havoc with this project, but capturing the planets… I always like it for Mars and for the minor planets that are closest to us because they have the most motion against the background sky. So you can take photographs, hopefully on successive nights or say every few days if you’re lucky, and then again layer them to actually show the motion of these objects against the background stars. And Vesta, it will gradually brighten it. It’s a quite decent little minor planet, so you know, well worth following. And it’s up in Taurus, so it’s very well placed to observe. So, and from now on, of course, Taurus and the Orion region will be getting higher in the sky as well. So, you’ll be able to follow Vesta as it moves against the background stars. So, that’s a long-term project, but we’re having a look at it now, sort of thing, whilst we’ve got a chance for this week.
Ezzy: So, yes, thank you, Paul, for taking us through everything that we can see in the night sky this week. A few specific events, on the 18th the moon’s crescent will just creep into the evening sky alongside Mars. They’ll only be up for a few minutes but hopefully you might be able to grab those before they go. And on the 20th Vesta will also be up in the night sky as well. Throughout the week it’s going to be a new moon or just after the new moon so it’s a great time to look at the deep sky and really take advantage of the dark skies as they return after the summer. So take a look at the Milky Way and all of the various different things you can see along that. And of course, all four gas giants will also be up in the night sky, so take the opportunity to take a look at those, particularly Saturn and its glorious rings, before they tip away for the next couple of years. So thank you very much for taking us through that Paul. It’s a pleasure. And if you want to keep up to date at home with all of the latest stargazing tips and advice please do subscribe to the podcast and we will see you here next week. Goodbye. If you want to find out even more spectacular sights that will be gracing the night sky this month be sure to pick up a copy of BBC Sky at Night magazine where we have a 16-page pull-out sky guide with a full overview of everything worth looking up for throughout the whole month. Whether you like to look at the moon, the planets or the deep sky, whether you use binoculars, telescopes or neither, our sky guide has got you covered, with detailed star charts to help you track your way across the night sky. From all of us here at BBC Sky at Night magazine, goodbye.
Chris: Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky at Night magazine. For more of our podcasts, visit our website at skynightmagazine.com or head to Acast, For more of our podcasts, visit our website at skynightmagazine.com or head to Acast, iTunes or Spotify.