What's in the night sky in the week of 12th to 18 September, 2022.


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 sky online at skyatnightmagazine.com or digital edition by visiting on iTunes or Google Play.

Ezzy Greetings, listeners, and welcome to Star Diary, a weekly guide to the best things to see in the northern hemisphere's Night Sky. In this episode, we'll be covering the coming week from 12th to 18th of September. I'm Ezzy Pearson, the magazine's features editor, and I'm joined on the podcast today by reviews editor Paul Money. Hello, Paul.

Paul Hello there Ezzy. This is a really interesting week, you know. Really good.

Ezzy Yeah. Oh, well, then, without further ado, please do tell us what we've got coming up in our night skies.

Paul Well, for his first start, the first two days, 12th and 13th, there's nothing happening. Here we start off with it's an interesting week and that is that the first two days is actually not very good.

Ezzy It's giving you a break to get ready.

Paul Exactly. They've got to get ready because on the evening of September 14th, we've got one of those wow events well worth trying for, depending on even even if you're a beginner. Have a look. Because the Moon occults the planet Uranus. Now, these don't happen often. So, you know, this is one of those times where it all works together, sort of thing. Some occur when the Moon's below the horizon and Uranus below the horizon so it doesn't work for us, but for the UK we actually do get to see this one. You need to be looking from about 10:30 p.m. until about 11:20 for the reappearance. Now, the disappearance of the planet is actually on the bright limb and that always causes problems. Visually, I mean, you've got to remember that Uranus is magnitude +5.7. The Moon minus... it's about -12, if I remember? Yeah. Pretty bright.

Ezzy Slight brightness difference there.

Paul Tis a challenge, isn't it? Yeah, yeah, yeah. But we're up for challenges at the magazine. We like our challenges.

Ezzy Absolutely.

Paul So, so but it's worth doing because you see a planet and the thing about stars, when they're coated, they go out straight away. They're a pinpoint source. Uranus, I mean, Pete's got a really good article about this in actual fact in the Sky at Magazine for September. And he actually points out that the disc in about 3.7 arcseconds in diameter, takes about 8 seconds for it to disappear. I mean, 8 seconds is almost an eternity. It's an eternity Ezzy. you know, it'll feel like it slightly. But I'll tell you what those 8 seconds will flash by when you're trying to image it.

Ezzy So, no, it's a it's a planet, not a star, because they just, like, blink out.

Paul Exactly. This is the point. That's why it's so different and so rare. We don't have many of these come along. So, you know, it's well worth having a go at. So you will need a telescope for this. And to be honest, you will ideally need high magnification so you can at least see something of a disc of the planet. But it'll still be interesting to follow it and see as the Moon creeps up towards Uranus and then begins to cover it. Now it'll be interesting if anybody does observe it sort of thing, you know, will we be trying and I'm sure I'll be trying as well. You know, cloud permitting, the usual caveat. There is an unusual thing, and I can understand why Pete didn't mention it is that, of course there is the moons of Uranus now because the moon is so bright. My suspicion is that they will be to faint. They'll be swamped by the moonlight. But yeah, I'll be looking out for them just in case you never know. And if you're imaging, you'd throw the gain up really high just to see if you picked them out. So you never know, you might pick them out as well. But the main event is this rather unusual occultation of Uranus. So this is on 14th September between 10:30 and 11:20. So do have a go at trying to find this sort of thing because I think I mean, seen again, Solar System in motion, isn't it? We're seeing the moon, moving against the background stars and in this case, a planet as well as a bonus. There we are. Now moving on, September 15th. The Moon, of course, is moving along. And any surprise... That was September 14th. Literally, it's about 15 degrees further across the sky, the Moon, from Uranus. So Uranus, as I mentioned the other week in actual fact is almost level as it rises in about 10:00 with the Pleiades star cluster the Pleiades and Uranus are getting into the evening sky now, a lot easier to see. So 10:00 as seen here. And we've got Mars in Taurus as well. So the Moon on the 15th lies below Messier 45, the Pleiades star cluster. Then on the late evening of the 16th, it actually lies above Mars. So there we are. So we've gone from Uranus to the Moon, passing the Pleiades to the Moon, actually passing being above Mars. And Mars will be quite bright. It is heading towards opposition and so... And it'll be quite bright. So another star, like another star below the Moon and that's no star, it's the planet Mars instead sort of thing. So I've been observing it recently and I've been quite impressed. I mean, there's not a lot of data, it's a small disc. And so, you know, but it's nice to see it back in the sky. And when it does get higher up, if you if you want to leave it for a few hours, it gets quite high up in the sky now. And so but it's a colour, you know, that gorgeous orangey, red, you can understand why they thought it was like a piece of fire in the sky itself, sort of thing. So there we are. And it's in Taurus. I mean, how easy is it to find Taurus? It's an easy constellation for a start, and it's got Mars passing through it. Okay. The next, even in the 16th, is also opposition day for Neptune. So we had Juno the other week and this is an interesting fact that when you have an opposition say, we mentioned Juno last week and Neptune is to the east of it and it doesn't take many days before with then opposition for Neptune. So this said be Neptune magnitude 7.8. So it's now visible all night, it lies in Aquarius, but only just and I say... It's a good guide actually, because the Circlet Star Asterism of Pisces is above it, is north of it. And of course, if you can't find that, well, you've got this bright planet called Jupiter to the left. And so there we are. So as a minor planet, Juno is still also to the right. So you've got Juno, you've got Neptune and you've got Jupiter as well. And I say Neptune is now visible. I love it when it gets to this point whereby it's actually visible throughout the whole night because it becomes easy to see for me from my back garden, because I've so much in the way in the sort of thing initially. So they are the September the 16th. Now. Some week's are a bit shorter than others because there's not as much happening. We stick with the Moon. But finally, the Moon lies between the actual horns of Taurus. It forms a shallow triangle also, and it of course is now getting a thinner crescent. So it's heading towards the horizon is getting lower and lower in the sky. And on the 17th it's actually a last quarter, so it looks like a half phase. So there are the moon's rising around about 11:00. It will be above the horizon, north east end in the horns of Taurus and Mars will be off to its right as well. So, you know, we have a sequence where we've had the Moon going past several objects to finish off the week, but it's always well worth having a look at and I wonder how many people look at the late night Moon. I do. Sometimes people say, you know where I'm sure the Moon after it's full, I don't see it? Well, that's because you've gone to bed. Yeah. You know, that's that's the clue, because normal people go to bed, you know, they spend the night asleep. The normal thing. The sensible thing. What do we astronomers do? We stay up! Mind you, we like to sleep during the day, which is alright if you haven't got a job, I mean our job sort of thing, you know we, we can mix and match a little bit can't we? We can actually observe because we can put the excuse to our editor. Well we're doing this for the magazine.

Ezzy I was working last night at 2 a.m. in the morning.

Paul Yes, exactly. So that's our excuse Ezzy and we'll stick to it but... So I mean you've not just got the last quarter moon sort of thing you know. It's one of the things last quarter moon and the first quarter moon it's a lot harder to see the Earthshine, but it isn't impossible. Because what you get is a very faint hint of the other off the Moon. So have a look at that as well. So there we are. That's the end of the week and another sequence of events.

Ezzy Well, it certainly sounds like this week is going to be a showcase for the outer planets. We've got the occultation of Uranus by the Moon, and that's happening on the 14th of September. That one's going to be really interesting if you can try and see it. So make sure you pick up the magazine, which will tell you how to go about doing that in a lot more detail. And of course Neptune will be an opposition on the 16th of September. So be sure to get your telescope out for both of those. And if you want to keep up to date with all the best things to see in the night sky every week be sure to subscribe to the Star Diary podcast and we'll see you here next week.

Ezzy If you want to find out even more spectacular sites that will be gracing the night sky throughout the month. Be sure to pick up a copy of BBC Sky at Night Magazine. Well, we have a 16 page Pull out Sky guide with a full overview of everything worth looking out for. Whether you like to look at the moon, the planets, or the deep sky, whether you use binoculars, telescopes on neither our sky guide has got you covered with the detailed star charts to help you track your way across the night sky from all of us here at BBC Sky and Night Magazine. Goodbye.


Chris Thank you for listening to this episode of Star Diary, our podcast from the makers of BBC Sky at Night Magazine. For more of our podcasts, visit our website at www.skyatnightmagazine.com or head 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.