Search for a comet in the morning twilight all this week. Get the details in the latest episode of our weekly stargazing guide podcast, Star Diary 29 January to 4 February 2024.
Chris: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the print edition skyatnightmagazine.com, or to our digital edition by visiting 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. As we are based here in the UK, all times are in GMT. In this episode, we'll be covering the coming week from 29 January to 4 February. I'm Ezzy Pearson, and I'm joined this week by Paul Money.
Hello, Paul!
Paul: Hello, Ezzy. Hey, guess what? Actually, in January, I've had some clear skies. I'm in shock.
Ezzy: Goodness. It has been, it has been very, very cold, but usually cold means it's quite clear, because that's one of the reasons it gets so cold. There's no clouds to keep all of the heat in.
Paul: Exactly. And they were very, very frosty.
I can assure you. But, so I came in like an ice cube. Having said that one of my Christmas presents from my wife was some nice new thick boots, fur lined, well, sort of faux fur, etc. And they were gorgeous.
My feet were... it was only me hands and me nose to be fair, a bit cold, but otherwise. Yes. Toasty which is good.
So hopefully we'll have some clear skies during the late January, beginning of February, sort of thing. So, uh, you know, fingers crossed, eh?
Ezzy: So what do we have to look forward to in the last couple of days of January heading into February?
Paul: Well, that's it. We'll have to begin- I'm sorry. It's the way how the sky works, but we're going to begin in the morning twilight. And this is where we find Venus low down now in the southeast.
You want to be looking roughly 7 AM. The sky is beginning to get bright. Mercury was with us last week if you remember, but it's dropped right back now and I think that's pretty well gone for the time being.
But Mars is possibly there. It's just had the conjunction with Mercury last week, but It's creeping up, so it's creeping up to meet Venus as Venus is coming down.
Unfortunately Venus is dropping away quite quickly, so it won't be long before we actually lose Venus. You've got to grab it, actually now, while you can, because...
If you like, it's the sort of thing if you like getting up and walking your dog before you go to work sort of thing, and they're nice crisp mornings, that's where the frost come in, isn't it?
But, uh, you know, and the dog's thinking, why are you taking me out in this? I want to be in the nice warm.
But we've got Venus. So southeast, you really do need, again, an uncluttered horizon. So, no trees or if there's trees nicely scattered, if they are. No big buildings or anything in the way.
So you do need it fairly uncluttered. But yes, we are into the last phase now, having Venus in the morning sky and then we'll have to wait a few months before it reappears in the evening sky.
But then that'll be more convenient, won't it?
Ezzy: Mm hmm. Absolutely.
Paul: Now, meanwhile, as we're in the morning sky, there is a comet. Comet C 2021 S3 PANSTARRS . It should be about magnitude +7.5. Now this is a bit of a challenge because we are in the twilight, so probably start a little bit earlier, say around about six ish. And it's in Scorpius, but it's passing Antares, the bright heart of the actual Scorpion itself.
So I'll say, use binoculars or a small telescope to try and pick it out, and on 3 February it lies to the left of Antares, but it is moving up. past the actual star itself. But I think the challenge will be, you know, will it be bright? Magnitude 7. 5 is good for binoculars in dark skies, but in twilight it might be a bit of a challenge.
But we've recently had several comets that have undergone outbursts. So it's always worth trying. You never know. I mean, if there's an outburst, it may suddenly make it brighter and more prominent to view. So it's worth having a look just in case.
Ezzy: Is this also a good comet that might be one for photography as well?
Paul: I think photography but again photography is going to struggle with the twilight possibly overwhelming it. Sometimes the eye is good at picking these things out whereas the camera gets swamped with the twilight.
Our eyes are an amazing thing, you know, they can cope with more things than normally a camera does.
I think it's the dynamic range, we have a better dynamic range with the eye. We can cope with variations in brightness in the same view, whereas a camera it's, this is the view, this is the brightness, oh dear, it's swamped it.
So you sort of expose long enough to get the comet, but unfortunately the twilight overexposes.
But it's worth trying. I mean, these things are always worth trying, sort of, just in case you can't actually pick it out. And at +7.5 magnitude, normally that would be quite a decent comic, wouldn't it? I know, not naked eye, but, you know, still quite decent.
Now let's swap to the evening sky. Yay! The evening sky.
Just to remind us that we've actually also got two planets that are also heading into the evening twilight. And that's Saturn and Neptune. They're getting quite low now, and you're looking at about 5.30PM, Saturn now lies in the twilight, setting shortly after 7PM.
So this is around about the 29th, this is the end of January, sort of the beginning of February.
Neptune itself will fare a little bit better because it's further up the ecliptic, and it sets around about 9PM. So at least the sky will have gone dark for the last part of it as it gets lower.
But because it's fainter, it's a double edged sword, isn't it? So it's fainter, so it's harder. And as you get lower, you're looking through more haze in the atmosphere.
So that can dim an object as well. So we'll have them for another week or two, but we will be losing Saturn and Neptune fairly soon, so they'll be soon gone.
But higher up in the evening sky, we've still got Jupiter and Uranus. And Jupiter is the dominant planet. There's lots going on with Jupiter. In fact, I thought we'd cover some of the sort of like movements of the moons going across Jupiter, because they're the fascinating ones.
It's pretty standard, isn't it? Oh, you look at Jupiter and there's some moons either side of it. Yeah, that's standard, but the unusual things is when they pass in front, and especially when one of their shadows passes in front as well. So at the moment we've got Jupiter Uranus, and there's a bit of a slight curve there if you add in the Pleiades or Messier 45 cluster as well.
So there's a bit of a curve with Uranus playing piggy in the middle, but over the coming weeks you will notice Jupiter is slowly creeping towards Uranus, so it is closing the gap. And Jupiter itself lies between the two constellations of Cetus and Aries as well. So it's fairly... I mean, it is a bright planet, so you shouldn't have any difficult finding.
When I was out the other night, it was, it was the dominant thing in the night sky. It's the brightest thing, other than the Moon and, of course, the sun and Venus in the morning sky.
Ezzy: It's always one of the first things when I'm on the walk home through, you know, light polluted streets, you can always see Jupiter shining brightly whenever it's up high in the sky.
Paul: Yes, I don't know about you, but whenever I watch a programme and they've got a twilight scene, I'm not listening or watching what's going on, I'm looking at the sky and seeing if I can spot a planet that's been catching by accident, or, or the Moon. And several times I said, oh look, l there's a moon up there.
They've, they've caught the moon. But, you know, ? I bet a few other astronomers do that as well.
30 January, that evening, you know, you wanna be looking from a eight o'clock until 11:30. But we've got a transit of Io across the disk of Jupiter, and then it's followed by the shadow of Io passing over as well.
So if you've got a telescope, this is a good time to look at it. The shadow itself is around about half past 10, it'll be roughly halfway across the Jovian disk. So here's one of the shadow and actual transits as well. So the transit of Io and then followed by the transit of Io's shadow from eight till about 11:30.
And then if that's not all the next evening, we've got almost a repeat, but it's not. It's Europa instead. And this time it's 7PM until about 11:30. Europa's further out, so it takes a bit longer to cross the actual disk, and so does its shadow as well. So 7PM till 11:30PM the next evening on 31 January, the last day of January, you can catch Europa going across the disk of Jupiter as well.
So I find them fascinating, because again, we've said this before, haven't we? They've got the rotation of Jupiter, so if you observe long enough, you actually see the clouds are slowly moving, the actual cloud bands, the planet is rotating. But you've got the added bonus of having one of the moons cross the disk and then it's shadow as well.
So you're seeing the Solar System in motion. You're seeing it work.
Ezzy: Yeah, there's quite a few people who've done animations of Jupiter, because as you say, it takes 10 hours to rotate so you can see that motion quite clearly, over the course of a night.
And we actually have a guide on how to create those kinds of animations over on our website, skyatnightmagazine.com. I'll put a link in the notes.
So please do look that up if that's something that you're interested in, especially given that you can potentially catch not just the planet rotating, but one of its moons and a shadow of a moon as well across two nights.
I think that's a really cool little project if anybody's looking for something to do with regards to Jupiter at the moment.
Paul: And you know, it's not often you end up with two nights on the trot, with two of the moons going across just like that. Usually you get a gap, and that's what'll happen shortly.
In the meantime, well, sort of late night through into the morning sky, the Moon is up. It is in the morning sky. So the evening skies are Moon free at the moment.
So that's a good time to look at the night sky and look at the winter stars, etc.
But the Moon is up, it's passing through Virgo. Now the thing about this is that, you know, we're starting really from 30 January through to 2 February Virgo is so big, it's so large, it takes the Moon four mornings to go through it until it gets to Libra.
So we start off, sort of thing, on 30th, sort of thing. Off to the far right of a star called Zaniah. And then on 31st sort of thing, it's actually forming a triangle with Porrima and Zaniah.
Then on the 1st it's right next to Spica. Mean, it's really close. There won't be an occultation. It'll be slightly above the star, but it is quite close.
And then. On the final, on 2nd February, it's actually at last quarter, and it's between Virgo and Libra, but sort of like the southern part of Libra itself.
And then ironically, on the 3 February, it does find itself right under Libra, below Alpha and Sigma Libra, sort of thing. And then to finish off on 4th, to finish in the week for the Moon, it ends up near Scorpius.
So, quite a motion there, you can follow the motion. But I just think it's quite funny that Virgo's so large, it takes four mornings for the Moon to pass over it, sort of thing. I mean, Virgo is one of the largest, I can't remember off the top of my head, but it's certainly either the first or the second largest constellation in the night sky, so it's quite huge.
And then, finally, on 4 February- We're sticking with fourth as well, sort of thing. And to end the week- we've got another transit on Jupiter! This is an early ish one, sort of thing. So, around about 6PM to 8PM, watch out because you won't see a moon passing front, but it's Ganymede's shadow, and it really crosses the very, very bottom edge of Jupiter's disc in the southern half of the planet.
So this will be interesting. It's a big shadow. Ganymede is the biggest moon in the Solar System. It's bigger than Mercury. You know, it's bigger than a planet. It should really be a planet. It's almost like a planet orbiting a planet, isn't it? So it's got a large shadow, so it's going to be stretched, and it'll be distorted because of the curvature of Jupiter itself as well, and it's on the southern hemisphere.
So that's a nice way. to end the week sort of thing, having a shadow transit of Ganymede on Jupiter. I'd say from about 6 till 8PM to catch that.
Ezzy: Yeah, I think that's a nice thing that it's that sort of proof that the planets are spherical I suppose, is the fact that you can see these shadow transits and they look different depending on whereabouts on the disc that they fall.
So I think this week, when you've got three of them together, that's a great opportunity to sort of compare and contrast and see what they all look like together.
But thank you very much for taking us through that week, Paul. If you want to keep up to date with all of the latest stargazing highlights, do subscribe to the podcast and we will be back here next week with even more highlights.
But to summarise this week again, we start on 29th January when Venus is going to be in the morning twilight.
You're going to need an uncluttered horizon to be able to see that one though. Throughout the week in the morning twilight, you'll also be able to see Comet C2021 S3 PANSTARRS. That's in the morning twilight. It'll be nearby Antares throughout the week, and by 3rd, it will be lying to its left hand side.
Moving forward into the evening twilight, throughout the week, you'll also be able to see Saturn and Neptune. It'll be a bit of a fight to see those two against the evening twilight, though.
You'll be much better seeing Jupiter and Uranus. They are going to be high in the sky, and we'll be also lining up with the Pleiades as well.
Then we have a triplet of transits across the planet Jupiter by three of its moons. On 30th January, Io and its shadow are going to pass. Then on 31st, Europa and its shadow will also pass. Then on 4th of February in the evening sky, Ganymede's shadow is going to be crossing across the southern half of Jupiter as well.
And also, it will be Moon free in the evening skies throughout the week, but if you're looking towards the Moon in the morning, you'll be able to see it pass across the entire constellation of Virgo from 31st January to 2nd February.
It will be passing by and forming triangles with the stars Poroma and Zannia on 31st, lying close to Spica on 1 February.
And then on 3 February, it will be moving over towards Scorpius.
So plenty to see in this week's Night Sky. And we hope to see you here back 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 pullout 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 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.
