Star Diary: What’s in the night sky, August 2021

A guide to August 2021’s night sky in the northern hemisphere. This month Jupiter and Saturn reach opposition, and the Perseid meteor shower appears.

Star Diary astronomy podcast. Find out what's in the night sky, March 2021
Published: July 29, 2021 at 5:06 pm
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August 2021 looks set to be a great month for summer stargazing, with Jupiter and Saturn both set to reach opposition (their closest approach to Earth) and the Perseid meteor shower on 12 August.


To find out how to observe these sights and more, listen to the latest episode of Star Diary.


Intro Hello and welcome to Star Diary, the podcast from the makers of BBC Sky magazine. You can subscribe to the print edition of the magazine by visiting scholar at Night magazine dot com or to our digital edition by visiting iTunes or Google Play.

Ezzy Pearson Greetings, listeners, welcome to Radio astronomy Guide to the best things to see in the night sky in the Northern Hemisphere on August 2021. I'm Ezzy Pearson and I'm joined on the podcast today by our Views editor, Paul Money.

Paul Money I see how things are going.

Ezzy Pearson Well, how's the stargazing been for you this month?

Paul Money It's been pretty grotty up until now. I actually got a night out last night and actually saw something. I was in shock. I mean, I take my hat off to our viewers who got equipment to review because it really is a challenge for them. A lot of people don't realise when you've got bad weather, you have limited gaps. And of course, if you're imaging something or doing something that needs Sky, you can't do it when the clear skies are when the moon's up. So so there's a lot of constraints there. But, you know, but they always managed to pull it off. So all hats off to them.

Ezzy Pearson Yeah. It's always good to hear that you managed to get out there and actually see something, even despite the bad weather. You know, it takes a bit of effort, but it's always worth it. So, what is your recommendations for August 2021?

Paul Money Well, we've got two really important oppositions this month, so we will come to that Saturn and Jupiter. And so they are really important because we get to see them all the way through the night. I always think that's quite a funny thing, actually, because some people say that most people don't realise that when we say all through the night, if an opposition occurs in the summer, it's a particular night. Whereas if it's wintertime, if it occurs, then you are talking about probably 4:00 in the evening, right through to nearly eight o'clock in the morning. So it's a very, very long night. So depending on whether you like short observing sessions, if you like, your opposition does something that's great, you have a short period, if you like, really long observing sessions, then the opposition is better in the winter. But in a way we will come to them. But let's just start off with another planet. Thank you, Uranus and our moon, because on the very first of August, we actually have the moon. Now, it's a day passed last quarter, which occurred on July the thirty first. So we're all because the first now we need to be looking in the morning around about I've set mine for three, three thirty and you'll find the moon is directly below Uranus. Now, the moonlight will wash out a lot of the stars, but often I use these as a good way of easily finding planets or other objects of interest when the moon that the moon is a great guide for that. So you have to look outside quite early. So if you're an early riser, that's all right. Before you actually get the sunrise, you can do it before sunrise. But obviously the sky gets lighter then, so it could split the moons about two degrees below Uranus and Uranus, obviously faint. You need binoculars, but you should fit them in the good field of view of the fifties. So you should be able to spot Uranus is little tiny dot. There's a few of the failed stars, but we've got good guides in the magazine, so well worth looking out for that. So that's OK is the first. Now, as it happens on the first, the moon is next to Uranus. The interesting thing now and I've been watching the motion of Uranus now for too many years. I see too many, but I've been amazed. I've watched Uranus move from Sagittarius. That shows you how long ago that was and it's now in Aries. And so it is creeping ever closer towards Taurus. And of course, a wonderful series of conjunctions in the next decade with M forty five the finest cluster. So it means that when the moon was next to Uranus on the first, on the second, it's actually to the lower right of the Pleitez and passes through Taurus and on the third is directly above the high eighties and the bright light was a red star. The red eye of the bull I think is more orange. The Aldebaran so but so. And then the forth sort of between forms, a bit of a triangle with the horns of the ball as well. So Taurus is quite a large constellation. Of course, you've got lots of clusters in it, which is really good to have the added bonus of the moon passing through it as well, I always think is a great highlight and I always look forward to seeing the earliest I can see Taurus rise in after the summer equinox, the summer solstice should say. And so we've now got Taurus back and he's getting into a darker sky. So getting excited because the winter skies are getting back. I know I'm I'm sad, really, although I was going on some morality in there and we talk about the winter skies, but you have to be open the early morning for this sort of thing. So, you know, so but I say it just. The fact that within a day that has gone from years into talk shows you how close you are and it's doctors now say it's been a long time, but I'm quite excited for it gradually creeping along the ecliptic.

Ezzy Pearson So if any of our listeners who aren't sure what Paul means when it says Uranus is in Aries, what he means is that the planet appears to be next to the constellation of areas in the night sky. And that happens because the planets all orbit in something called the ecliptic. And as they go around the sun, they appear to move across the night sky and along all of the constellations of the Zodiac. And because Uranus takes so long to go around the sun, it really, really seems to creep across the night sky. So you've got something like Mercury, which which is around the sun every eight days that seems to go around the sun really fast. But you're looking out at Mars that takes two and a half years. So it still whips across quite fast. But something like Uranus takes 84, four years to go around the sun. So it really, really does creep along through

Paul Money these different constellations. Yes, and and, you know, to watch it creep like this, it just feels at times it does feel it's inexorable all along. But now I'm looking at and think, wow, I is really shifting. So in in the lifetime of and, you know, I always have a bit of a joke with my father and the fact that, you know, that old I'm nearly at the age of an orbit of Uranus, it it's quite really appreciate that. So not the planet Earth or something like any other planet except that one.

Ezzy Pearson So Uranus seems to be certainly making its moves across the night sky this month. But what else is there that we should be paying attention to?

Paul Money Well, we touch on the first opposition then, because we've got such an opposition on the second. It lies in cutting corners. And of course, when we say the lie in the constellation salting, the stars are so far away that there's no relationship there whatsoever. It is a line of sight effect, but on the second it reaches opposition. Now, the thing about opposition, it really does mean this planet is opposite the sun in the sky. So as the sun sets, then the planet rises. And then later that night thing when the planet actually sets, the sun rises. So it literally is of the hundred and eighty degrees away from the sun in the sky. So we get to see all night, which is why I mentioned earlier. But the fact that in the summer, it means you don't actually see it for that long before the sun rises again because it's such a light night. But sun is a bright planet, so we can actually see it really well. And we have got the advantage of the not too far away is also Jupiter. And we'll come to that a little bit later on because it's the opposition this month as well. The sun is well worth now putting a telescope to have a look at the rings you tend to find round about the time of opposition. The rings bright is an interesting effect where they actually brighten and he's down to these opposition effect whereby literally in line with the sun. So they're reflecting the most light. They come back from the rings, from the sun. So worth looking out for that. And of course, if you got a telescope point, it is the planet. I mean, I'm I'm always taken aback when I look at Saturn. I'll just think it's so gorgeous to see those rings around it. I mean, the other planets gather interesting, but I haven't got rings. Saturn got the rings and it really catches people's attention. I've done quite a few public events showing people Saturn and he really has got rings. And you think, well, it's called the Ring Planet for a reason.

Ezzy Pearson And the thing I've always noticed, because in order to look at something like Jupiter, that is a beautiful planet and it has all of these bindings and the great red spot, but you do need to to really know what you're doing and have quite a good instrument to be able to actually see those visually. Whereas with Saturn. We relatively quickly, relatively easily, you can see it's it's it is as the cold appendages. Yeah. It's one of those very, like, easy things to see and it does look absolutely spectacular. If you have never seen the rings of Saturn, highly recommend that.

Paul Money Oh, definitely. I mean, I actually have seen them in spotting scopes. And so if you got bird watching, spotting scopes, put it on Saturn because you couldn't see it. And even the larger binoculars will give an impression that something is is odd is not right. Jupiter's round. Saturn's what is it, oblong. Strange, elliptical. So, you know, there's something strange about it. Of course, with a telescope, you might better split the rings with the Cassini division between them and you'll see, hopefully the dusky Northern Band and the dark Apollo as well. But don't forget, they got a whole retinue of satellite moons going around it, the brightness of Titan. So Titan is actually quite well. So you can see Titan in large binoculars and follow that going around. It's about 16 days for the orbital period. So that's worth looking at as well. So it is a gorgeous planet and I never tire looking at it. And so the beauty now, course, is that once he reaches opposition, it means that you're going to see more and more in the evening sky. And I always find that with a planet in the morning sky, it doesn't get the attention unless you're real diehard astronomer and or somebody really into looking for the planets. Whereas if you're a casual observer, you start to notice from now on, you'll start to notice it more because it's becoming earlier and earlier and better place to observe at a more convenient time. So, you know, so people can get out and see it when they're walking the dog, perhaps just before they go to bed, they could actually see it over in the south east. So, yeah, it's it's a gorgeous planet and from now on it can only improve. So we've got the weather, we've got the clear weather, but it is definitely well worth looking out for now, especially now it has opposition. And we've got an odd event. I'm one of those that I like difficult ones, but August the 5th, so we've moved on a few days down, August the 5th, the crescent moon is in the morning sky again. Sadly, you have to get up. Yes, but you have to be looking towards north, north, east and really look around about on about 330 ish again. So I think fairly early morning. But I like it when the crescent moon is close to or in this case, toolchain effectively a cluster of star cluster. And it's a nice bright star political message. Thirty five, it isn't as bright and splashes, say the Pleiades, which are really I mean, they're bright, naked eye stars when people see between six and nine stars, Naked Eye, my best was nine sort of thing. But nowadays the glasses is dropped down softly and fried. But the thing is, I'm thirty five. It is a nice cluster in Yemenites at the feet of Kastor, one of the twins of Gemini. And you've got these crescent moon and it's actually covering some of the top, most northern most stars and I'm thirty five. So although they'll be a bit of light from the moon, I have to say because it's a crescent it won't be quite as bad as you wouldn't really try this at half face or full face because it would drown out the stars completely. But this is a chance to see the star close to these faint stockhorse. You'll see only the brightest members, but put a telescope on it or large binoculars and you should see the crescent moon and then the faint sprinkling of light stardust in the background, because, again, it's a line of sight effect, but normally they're often quite a distance apart sort of thing. So this is an unusual event. It's actually appears to be overlap in the cluster itself. So I love these sort of events just because they're a bit more of a challenge. It's nice to have a bit of a challenge to push yourself a little bit more observations, whether you're doing it photographically or whether you're doing it visually. So there we are.

Ezzy Pearson That does sound like a remarkable photo opportunity. So if there's anybody out there who's who's looking for a target this month, maybe that's the one I want to try a date.

Paul Money Definitely a challenge, because it getting the balance right between the crescent moon. Of course, the crescent moon will also show the earth shine. So it'll be a good idea to try to get a sequence of pictures and merge them together to show all three the cluster, the sun and the moon down on the right side of the moon. Now, that's a challenge. So, yeah, hang on. I might try that.

Ezzy Pearson Yeah, that's us doing that particular challenge. You managed to be successful. Make sure you send it into the magazine.

Paul Money The show, almost atmospheric is the wrong word in one way. But they are beguiling in many ways because you see this. But don't leave it too long because as the sky gets lighter and the moon will start to creep away. Well, was doing it at the right time, the time I've got set for a lot of this was actually just on to it's about two 20. So if you leave it later, you'll see the move crept further away from the closed door itself. So about 220 maybe over in the east, then half.

Ezzy Pearson Remember, the moon does move over the course of the night.

Paul Money It's surprising when it's close to a bright star or planet or or an object like this, you begin to realise how much it actually moves even during the course of an hour. So this is the beauty about occultation works not to observe vocalisations. You suddenly realise just how much that moon moves. Now, a few days later, we're talking about August the 10th and 11th. Let's do something nice and easy. Let's get back to the evening's guy that we're all more familiar with. And it's still lightish nice, isn't it, at the moment. But if you're in the evening, Twilight, you want to look at about half an hour after sunset towards the west and we still got Venus. Venus is it's like I'm determined not to go. You've had me for several months now lingering along the sort of Western horizon. I'm still going to stay here for a while. And it does. And it finally will improve later in the year. Quite amazingly, even though you'd expect it to disappear, it will actually start to improve. And that's the combination of the ecliptic sort of thing, gradually beginning to step. And as we get along later in the year, heading towards September and October, but back to now, on the 10th and 11th, you shouldn't really need to guide you to Venus because Venus I was actually looking at it just a few nights ago. I was amazed. We had an evening twilight that was clear, typical one night that I thought it might get knocked. Elution's the to and clouds were brilliant the night before that night, absolutely zilch. So it waits until I have a clear mind to go away. But so they still around. But we'll start dissipating when we get into August. But on the 10th look to the right of Venus and there'll be a lovely slim crescent moon that the moon will swing into the evening sky by then. And then on the 11th, the crescent moon will be a bit thicker. But to the upper left of Venus as well as say you should really need the moon to guide you to Venus. But in this particular case, usually you can spot if you spot the moon in daylight and be careful, of course, with the sun's not being to always hide the sun behind our house when they want to look at something like this to block the view of the sun, but then use binoculars. You can use the moon because that's easier to say. You can use the moon than to find a tiny pinpoint of light in daylight. That is Venus. And yet when you get into twilight, Venus dominates because it's such a bright planet itself. So there are 10th and 11th. You've got the crescent moon passing Venus in the western skies. NASA will keep Venus all month. You better keep an eye on that as it lingers there. Now we come to August the twelfth. No, no, no. I'm not talking about the event usually for August the 12th. We've got another little one before because we do like conjunctions and a we got a chance to see really the last gasp of seeing the minor Will Vesta. Now, Vestas is deep in the Taiwan right now, so normally you probably won't bother with it sort of thing. You usually observe it probably when it's dark skies. But again, if you look around about nine thirty in the evening, you should be able to find the moon quite well. I mean, that's obvious, isn't it? But to each right, there'll be a bright you start there. She's Poppema Gammer Virgin is. And the thing about it is that directly above, as we look on the sky, I'm not talking about North as in sort of the orientation of the sky and the way we do rochus ascension and declinations. It is literally a bull Paramor forming a triangle. And we've got Vesta now again, you'll need binoculars to try and find it, but it is a regional problem. It's about seven and a half magnitude, so it isn't impossible. But it might be your last chance to see Vesta and it's just nicely, conveniently, directly above PAMA. And of course, we've got the moon to guide us to both. So there we are, a nice group in there to have a go at as well. But August the 12th, the peak of the Perseid meteor shower, I mean, this is the one I always look forward to because, you know, it's going to be reasonably mild. But I love the Geminids later in the year. But hole that can be I mean, a lot more meetings, but it's cold, isn't it?

Ezzy Pearson Yeah, it's in December. They're they're physically challenging. Yeah. Yeah. It's taking out on a December night.

Paul Money Exactly. I mean, we always recommend having a lounge to watch mateys. But if you're in a lounge in December sort of thing, you know, lounging by, you've got to be really well wrapped up and not worry that you don't fall asleep, you know. So I think it's one of these things. You tend to have a group of people around you, Monju, everybody. Would fall asleep if you get too comfortable, but this is this is Bob, hopefully barbecue season still, so get to friends around sort of thing now that restrictions are gradually easing and have a have a view of the Perseids, the venue family. Right. Which is the theoretical best. Right. If you're looking directly above you. So the clearest part of the sky is put it around about a hundred. But the trouble is you don't usually see that that's a hundred per hour and that's on the absolutely perfect conditions. And that's why we continue to rely on FEMA.

Ezzy Pearson If you were staring at exactly the right point in a perfectly clear sky with perfectly dark sky. Which doesn't exist

Paul Money exactly, but it's a guide, but you always have to I know Pete Lawrence and I, we've discussed this before and basically you're looking at around about a quarter or a fifth of the actual right. But don't let that put you off, because I found that coming flurry's often. And so you'll get one and you keep watching until they get to three and then go quiet and probably have five, ten minutes and nothing happens and then you get another flurry. So it's well worth looking out for. And the great news this year is the although the Moonies in the early evening sky do sit around about 11 ish. So the thing is sort of thing, you know, you will I mean, it's low. So it doesn't as he gets low, the moonlight doesn't really interfere as much. And so it's well worth looking out for in the radiant in the north east and gradually getting higher during the course of the night. It's not too far away from the top end of Perseus itself, hence the cold the Perseids. And so it's well worth keeping a look out. And I say it's not that cold. And you often find the best ways to look. Not quite at the radiant itself. Look away. We always say about 60 to 90 degrees away from the radion because that's where the streaks are going to be the longest, because they're working the angle. If you looking straight towards the right, looking into them, it's a bit like, you know, when you're driving. I mean, this is a reminder of winter now, but you're driving on those rain driving towards you. What happens is the rain looks as if it's coming straight at you, don't it? Because you drive it into it doesn't necessarily mean it is because it's falling from the sky. But you drive it into it. So it looks as if it's coming straight at you or something. So you don't see much in the way of streaks. But if you look at the side of the wind, you see the rain streaking past the actual car side window and it belongs to and that's the same with the sky if you look straight towards the radio looking into it. So the almost head on. So the very tiny streaks, you do get some dramatic ones. I have to say. I've got some really nice ones that are really short but bright. So they're a nice surprise. The best ones are actually to the side. You look around and that gives you quite a large area sky. You look from the Great Bay, the Bear, Draco, Hercules or Cygnus, Saffire, some Pegasus, and you often find there where you're going to get the longest streak sort of thing of the mate is. So it really is a good one to say the moon. Well, actually set after eleven o'clock and so there'll be no moonlight. You'll have dark skies as well as you'll have quite a long time to observe. There's only about clear skies. And this is this is one which is at least more favourable in terms of the resi being nice and warm or relatively warm compared with the depths of winter when we have meteor showers, then

Ezzy Pearson hopefully even even if it's a bit cloudy and you're trying to fight through that, because that's one of the things I like about meteor showers, because they go on throughout the entire night and you never know when one is going to appear, even if there is a bit of cloud in the night sky. I would say if it's partly cloudy, that means it's partially clear.

Paul Money I like that. All that's so positive. I love it. Yes, exactly. Exactly. So you might get that one. And I'll tell you. Well, it's happened a couple of times, but I've had the odd meteor in the Gap. And I'll tell you what actually makes it feel more special. It's almost like he's been framed.

Ezzy Pearson So, yes, even if the weather isn't a hundred percent brilliant, even if there is a bit of clouds, it is still worth trying to get out there and of meteor, make it a bit of a challenge. Can you see one through the clouds? So that's on the the twelfth will be the peak of the Perseid meteor shower. But what is happening in the second half of the month?

Paul Money Oh, well, we get into the opposition of Jupiter, which occurs on, you could say on the late night of the 19th into the 20th. My records show that it's from the US Naval Observatory. That is it's literally on the borderline zero GMT. That is, of course. So if you actually had British summertime. So that really is one o'clock in the morning on the twentieth, but it's just not borderline. So view from the nineteen to the twenties. And that's the opposition night of Jupiter and as we mentioned, actually with Saturn. So I think this is now when he's visible the best you get it all night sort of thing sets as the sun rises, the sun sets and vice versa. And so it gives us the longest time to view it, although as we mentioned earlier. So I think we're in a position whereby they're in a place, they're in the sky, where they're in Capricorns. And the last few years, you don't get as long a session because it's in the summer sky, these oppositions. But the good news with Jupiter is that it moves a lot quicker. Remember, these orbital period is about twelve years. So it is moving quite a decent amount each year. Almost an entire constellation on a switch is now climbing the ecliptic and it is definitely going to improve. So where we've had. The last few years low down in Sagittarius and low highs, anything can actually spoil the view and certainly image wise it doesn't help us. Now is beginning that climb open. It will climb quite rapidly over the next few years into really favourable observing. So now's the time to get it sort of thing. Opposition creep back into the evening sky. From now on, making it a lot easier to observe. You mentioned earlier the Jupiter's got the bonds that the two main bands, the red spot needs a bit more work sort of thing. Well, red spot mania, OK, pale salmon colour sort of thing. You know, it is actually quite faint.

Ezzy Pearson It has been fading in colour. Yeah.

Paul Money It's shrinking as well sort of thing. So that a lot of speculation is are we going to lose the great red spot. It could be that we don't know do we? We don't know whether that's a phase in whether it might grow again. We it was a great patriot, Patrick Moore, quite frankly, we don't really know. So that's a terrible impersonation. And I've got the initials PMB to go with it. But it is so. And of course, the great red spot is one of those things because the planet rotates in just under ten hours. I mean, that's a fast rotation and we're just on a little longer with last twenty four hours, but just a ten hours just to turn once so you can see the turning of the planet quite quickly and you begin to realise that features are actually drift across and then drift across the surface of Jupiter, Jupiter actually turning. So it's always fun, sad really, but always fun on the other side of Jupiter. Relatively boring when you know the great red spot is invisible sort of thing. But there are plumes and features that you can see with a telescope. So it is still worth looking at as well. And of course, you've got the full Galilean moons, which are easily visible and you can see them in binoculars. It is a bit of a challenge because they're quite close to Jupiter and you have to observe them when they're up. They're furthest from the planet, but definitely have a go at Jupiter and see if you can pick out the moons. And obviously a telescope will show them. And if you look at the highlights, the August highlights in the magazine brings out the fact that we're going through a phase with the opposition, that you actually get some mutual events with these moons as well, sort of occult each other and, of course, the passion in front of the planet as well. So you've not just got the moon passing in front, you've got the shadow of the moon actually transiting across the disc as well. So there's a lot to say. So now that Jupiter is the opposition, it will start to get easier to see in the evening sky. So, again, I was reading opposition. Yes, it's going to be easy for me and I would have to stay up so late to call myself an astronomer. Good grief. But, you know, I'm still human. I still have to get up in the morning at times as such. But one of those things now that was actually on the 19th, 20th. But interestingly, our moon joins in the fun over the next few days because on the 20th it lies sort of below Saturn. So so we got there and then it forms a triangle. So the moon forms a very long sort of triangle, not quite right angled triangle with Saturn and Jupiter on the twenty first and then on the twenty second, the moon is to the lower left of Jupiter itself. So I moved to get in on the act as it does now. It goes round so much and it passes so much. He's going to get into the act and many why features so much in Star Diaries. Because it's so busy so near the end now. And we jump to August the 30th because we mentioned the moon passing through Taurus right at the start of the month, the second, third and fourth. Well, when it does that, it means that the end of the month, it's got to be somewhere close to that vicinity again. And on the 30th, it's directly in line between the Pleiades massive forty five and the heightism Aldebaran as well. So if you miss it on the early part of the month, you've got the end of the month and you'll find the moon once again back in hours. And I'm saying this time it's actually between the two clusters on The Bright Star as well. So it's a nice way to finish off the mountain, although, again, it has to be an early morning stop for that one as well.

Ezzy Pearson As I know it sounds like it's going to be a pretty full month. So to go back over that, all recommendations for the month. Well, right. The beginning on the 1st of August, Uranus will be next to the moon. Then following that, on the 2nd of August, Saturn will be out of position at its closest approach to Earth. Then on the 5th of August, the crescent moon will pass through the cluster M thirty five. And that should be a great observing opportunity and maybe even a bit of a photograph opportunity. If you fancy a bit of a challenge, then on the 10th and the 11th, you'll have Venus passing through the evening sky. On the 12th of August, we will have the Perseid meteor shower. So if you're listening to this, if you're a bit of a beginner maybe, or even if you're an advanced person who's just looking for a nice, relaxed observing session throughout the night, always make sure to check out the Perseid meteor shower. Then finally, at the end of the month, on the 19th and the twenty, we have the opposition of Jupiter. So if you fancy getting to see those bands of Jupiter, maybe even spotting the great the great salmon spot doesn't quite have the same ring to it. So I'll keep calling it the great red spot. That's the 19th to the 20th that night. You'll be able to see that over on Jupiter. So thank you very much for joining us today, Paul, and giving us that detailed account of what's coming up in the night sky this month. Thank you. If you want to find out even more about the spectacular sights that will be gracing the night sky this month, be sure to pick up a copy of People magazine where we have a 16 page pilot, Skyguide, with a full overview of everything worth looking up for in the August 20 21 night sky. Whether you like to look at the moon, the planets or the deep sky, whether you use binoculars, telescopes or Neba all Skyguide has you covered detail star charts to help you track your way across the night sky from everybody here. BBC Sky Light magazine. Goodbye.


Intro Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky nine magazine, which was produced in our Bristol studio by Brittany calling for more of a podcast, visit our website at or head to over to iTunes or Spotify.


Elizabeth Pearson
Ezzy PearsonScience journalist

Ezzy Pearson is the Features Editor of BBC Sky at Night Magazine. Her first book about the history of robotic planetary landers is out now from The History Press.


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