What's in the night sky of the week of 23 to 29 January 2023 in our weekly stargazing guide.

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 digital edition by visiting on 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 GMT. In this episode we'll be covering the coming week from 23 to 29 January. 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 Money Hello, Ezzy. Wow. I can't believe we're dealing with the end of January already.

Ezzy I know. Time goes quickly.

Paul It's not fair, is it? However, now, last week we almost left you on a cliff-hanger because we had the conjunction of Venus with Saturn. Literally the next day, so that was on Sunday, the next day, Monday 23rd, they're joined by the crescent Moon. The Moon is back in the evening sky. Now deep sky observers will probably go "Boo!" Because it does mean it'll get higher and higher and start to interfere with the night sky. But you're alright! I always say you're alright the first week until it gets the first quarter.after first quartet, then it interferes more. So on the 23rd you have this really thin crescent and this'll be to the left of Venus. Now Venus will now be slightly upper left of Saturn that's how much Venus moves. It was below left of Saturn at conjunction, it's now to the upper left of Saturn on 23rd. So the moon joins them and this will be a great photo opportunity, but it'll also be great in binoculars as well. So do get out, have a look in the evening twilight for this. This ephemeral moon with Venus and Saturn in the evening sky. you don't want to be looking towards really the southwestern horizon, I would say about 5:30. I always make sure you've got to make sure the Sun set. You know, that's golden rule, isn't it Ezzy. Always, make sure the sun has sent out the way, but don't leave it too late because obviously they will set because they're in the twilight as well. So 5:30 UK time an ideal time to actually see them in the bright twilight and follow them down, setting. But you do have to have, we often say this, but a long plotted horizon. This is the problem with lots of the events. What we see do happen towards the horizon, don't they? But then that's because we're dealing with twilight planets.

Ezzy Yeah. If you if you, if you're dealing with the planets, they do tend to be a bit lower in the night sky unfortunately because of the way that the Solar System works. But sometimes they get a bit higher in the night sky. Venus is going to be reasonably high in the night sky this year. So that's going to be a great chance to see that.

Paul Yes, it's a great year for Venus, in actual fact. So, you know, that'll be great to watch that creep out and get higher because we tend to think of the twilight planets - Mercury. Mercury always does linger in the evening twilight, whereas Venus always like... makes a break for it Ezzy. You know, "I'm going to get away from the twilight". It can be seen for several... I guess the point I can set four hours after the Sun. So that's in a dark sky and that's when it can be quite dazzling as well. So yes, we'll have some good views of Venus this year. Now, though, couple of days later and we're dealing with the moon again, But it makes a lovely triangle with Neptune and Jupiter. This is the 25 January. Look, a little bit later, about 6:30 sort of thing, you know, But he's high in the sky, so they will take a lot longer to actually set, but they're not too far from the Circlet of Pisces. This is an interesting asterism. We have the constellations, which are the traditional constellations, which we know as Pisces the Fishes, etc., Pegasus, the Flying Horse, etc.. Well, with Pisces, the end of the right hand of the fish is actually they call it a Circlet. Well, this is the oddest Circlet I've ever seen, so definitely not a circlet as far as I'm concerned. But it's an interesting sort of, you know, shaped feature. But we call it the circle of Pisces. Now, Neptune is sort of like, you know, not too far from that. And so all we've got is we got Neptune, then a little bit higher up, we've got this crescent Moon and you should still see some Earthshine. But it will be diminishing because the crescent phase is getting thicker and then almost a bove and slightly to the left will be Jupiter. Now Jupiter is obvious, you know. It's very bright, other than Venus it's the brightest object in the night sky. But you've got this lovely Moon forming this like, shallow triangle with Neptune and Jupiter. And because the distances are almost equal, you can give that as a guide to finding Neptune. Now, admittedly, you do need a small... Large binoculars or a small telescope and a good finder chart. And obviously we provide them in the magazine and online as well anyway. So, you know, it is well worth having look. Just I think photographically you can get them because Neptune will show up photographically quite well and you'll be able to identify using the star charts which dot of light is actually Neptune. You can get a picture of Jupiter, the Crescent Moon and Neptune all in one go at the same time. Obviously, you know, it's worth having no telescope on them. But you know, it's a nice it's nice to see it naked eye and then scan with binoculars and then home in with a telescope to each one.

Ezzy Yes, because as you said, it does form a pretty perfect looking isosceles triangle with the moon at right at the tip. So if you are maybe looking to try and find Neptune for the first time and you want a bit of help and a bit of guidance, this could be a perfect week to to try and do that. Because Neptune, it is one of the trickier ones, it is not requiring binoculars or a telescope, unlike most of the planets which are just you look and they are there in the sky all big and bright and obvious. In fact most of the time, if you notice something bright in the night sky, it's probably a planet.

Paul Yes. The number of times I've been asked "What's that bright star next to the moon?" I've often said, "That's no star, that's a planet." Cause that's usually the case as. But as we do note these stories, you know, the moon does pass some of the brightest stars as well. But, you know, it has some really good encounters with planets, which I always like, especially when they're really close. And of course, last December we had the occultation of Mars that was like not just a close one, it's a complete finish. So I want to finish this week. It's a bit of a long list, but we mentioned Comet C 2022/E3 ZTF and the ZTF is this Zenith Transit Facility. And they were the ones that discovered it. I mean, they get confusing down there with all these different surveys Leonis and all sorts of thing, you know, to actually find these. Panstarrs as well.

Ezzy I think a lot of people are just referring to this one as Comet E3

Paul Yeah. Yeah.

Ezzy To make it a bit a bit more... less of a mouthful.

Paul Exactly. Sort of thing. So E3. So it sounds like something you'd find in a movie, a sci fi movie as well. It actually moves into being circumpolar and may brighten to naked eye visibility. Now binoculars should be enough to actually follow it. On 23rd it lies next to the star Iota Draconis. So they'll give you a if you've got a star chart, you can find Iota. And in actual fact, it's the curvy part, curving between the two bears. So it's curving around Ursa Minor, and then the rest of Draco lies between the two bears, the great bear and the little bear. So this is a great.. I mean, you know, if you can find the pole stars, you can find the great bear, you should be able to home in on this region to find this comet, this new additional object to observe. So on 23rd lies close to Iota Draconis. We think it'll be about magnitude 5.6, +5.6.. Now that's technically naked eye. But you do need a dark sky, no light pollution. And ideally for that you should be really high as well. Well, it's getting up towards the pole star, so it's not doing too bad. So it's tracking now between the two bears. It'll be closer to the little bear, to be fair, but at least you've got an idea of where to look. So on 27th, it lies just a few degrees away from the second brightest star in Ursa Minor. This is beta Ursa Minor, Kokab, so that's a key to look for it. And Kokab is a sort of yellow orangish stars, so they're nice coloured star for you to actually look at as well. Now by the time we get towards the end of the week, we hope the comet will have brightened to around a magnitude of 5.0, perhaps 4.8, we don't know. Comets are very fickle things Ezzy. You know, we've had plenty of comets over the last few years where we had great expectations and you know, so them I think there's a book you could write called that. So anyway. The thing about it is they can often fizzle, you know. So we have great expectations, hoping they're going to be great and we can keep our fingers crossed for E3. It seems reasonably consistent, so fingers crossed that we can actually see it. And as it gets brighter than magnitude 5.0, so if it does get to 4.8.. but getting close to the sort of magnitude of the core of the Andromeda Galaxy. So if you can see the Andromeda Galaxy, there is a good chance with a good sky, dark sky, you might see it as a little fuzzy haze. But don't get too excited, it'll be a fuzzy high. But binoculars and a small telescope should show it quite well. Now on 29th. It will lie roughly on a line. If you take a line from the pointer stars to Polaris. That's why they call the point stars. Not to be confused with the Pointer Sisters, which of course is a pop group. But the pointer stars is the Great Bear point up towards Polaris. We often use them, that's why they called the pointer stars, because you can find north. You find the pole star, you're looking north. So this is a great way because you can follow the pointer stars. And if you sweep up with binoculars, there should only be one fuzzy blob. And I do look my fuzzy blobs in the night sky. But this will be really fuzzy because it's a comet. So there should only be one fuzzy blob on that line between the pointer stars and Polaris. So if we sweep around the area, you should find the comet. So we've got great hopes. I hope we won't be disappointed because obviously we're doing this sort of thing a week before. Just fingers crossed it could happen. So, you know, this will be at its brightest. And it's high. And I mean, it's well placed, it's visible all night. You know, when you've got an object in the vicinity of the pole star, you know, you're circumpolar. So you've got all night if you wanted to observe. And if you do follow it all night, you will actually pick up the motion. You'll start to see it moving between individual stars themselves. So I always find that exciting as well, because you you get a sense of the Solar System in motion as well. We often sort of lose that because the sky looks fixed. So when you get an object that's moving quite quick across the sky, literally each day is in a different position, then you get a better sense. And if you can see it moving within, say, a few minutes with a telescope view. Then I think that's quite exciting. So gives you a real sense that you're in a working Solar System. It's operational.

Ezzy It's you do kind of forget that because these things – especially with something like a planet or an asteroid or the moon, which is something else that you can see drifting across the night sky – you kind of forget how fast these things are moving because it takes weeks to go a tiny distance across the night sky. Faster in the case of the Moon. But actually, these things are going to in the tens of thousands of kilometres per hour and the travelling, speeding around the Solar System.

Paul And they're just so far away. The apparent motion looks small to us, doesn't it? Sort of. And that's the problem. Yeah.

Ezzy Exactly. It's the distances involved are rather large. But yes. And comets, as you said, are a great way to sort of see that motion across the Solar System. They're also one of the very few unpredictable things in astronomy. So much of this thing's so much more sort of we can predict, you know, decades, centuries and even in advance, whereas comets, it could be the day before. You don't know what's going to happen, which is why we have a running guide keeping track of the comet, Comet E3. So if you want to have really up to date view of what's going on with that comet. Be sure to head over to www.skyatnightmagazine.com. Link should be down in the show notes so you can go straight there if you want to find out more about the comet.

Paul So there we are is a great way to end the week. Go isn't it? With a comet. An extra visitor to visitor to our skies.

Ezzy Yes, it does sound like it's been it's going to be a really good week starting on 23 January. We've got Venus and Saturn will be close to each other, joined by the crescent moon in the evening sky. So a great time to see that. 25 January, the Moon, Neptune and Jupiter will be forming a lovely triangle, which is great opportunity to try and find Neptune if you've never looked at it before. And they'll be hanging out near to the separate of Pisces. And throughout the week from 23rd, right the way through to 29th, going beyond hopefully Comet/E3 will be in the night sky, perhaps maybe even getting up to the stage where you can see it with the naked eye, if you're lucky, in a good side. But you never know how these things are going to go. So hopefully there's lots in there that you can. So hopefully there's something in that that you'll be able to get up and see this week. Thank you very much for taking the time to talk to us about all of those things.

Paul Pleasure. And we'll see you next week.

Ezzy And if you've enjoyed us running down all the things you can and if you enjoyed hearing running us down, all of the things that you can see in the night sky, be sure to subscribe to the podcast and maybe think about leaving us a review. It really does help us and make sure that we get out there to even more people. So thank you very much 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 where we have a 16 page pull-out Sky guide with a full overview of everything worth looking up for. 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 the 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 skyatnightmagazine.com or head to Acast, 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.