What's in the night sky in the week of 20 to 26 February 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 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're based here in the UK all times are in GMT. In this episode we'll be covering the coming week from 20 to 26 of February. I'm Ezzy Pearson, the magazine's features editor, and I'm pleased to welcome back expert astronomer and astrophotographer Charlotte Daniels.

Charlotte Daniels Hello. Thank you for having me back!

Ezzy It's always a pleasure. So, Charlotte, what are your recommendations for the coming week?

Charlotte Lovely. So we're looking to from 20 to 26 February now, and we are finally in New Moon territory. So we are still able to make the most of our Comet C/2022 E3 ZTF or as we like to nickname it Comet E3. We still have time to appreciate it before it starts to fade too much so let's start with that. So the comet, by this stage we more or less parallel to Orion's bow. So as you look to the right of the main constellation of Orion and his belt, you'll have this curved line of stars that represent Orion the Hunter's bow, and they're each called the Pi Stars and the six of them from Pi 1 to Pi 6. Comet E3 will be making its way down this line of stars parallel to it from 20 February onwards. And by 21 February, if you drew a line from Bellatrix in Orion across to the third star in the bow Pi 3, the comet will be slightly up and to the right of Pi 3 in the evening. So that's a really nice way of being able to track it. I do love to be able to star hop to phenomena. It really does help and it's nice to see how this comet is transiting the sky throughout the month. So we should be able to still see Comet E3 through binoculars, so do try and track it before it gets dimmer and move further south and out of our sight. So as I say, the great thing is we are all going to be having a new moon on 20 February. So not only will this help us to locate Comet E3, but it also really helps us find those faint and fuzzy deep sky objects that can be tricky at the best of times, especially if you don't have a Go-To mount that helps you locate things and tells you something's there and then lets you dark adapt your eyes and you have like faith that it's found it for you. So the new moon is a great opportunity to get down to some good old fashioned observing time. And I'm not just talking about nebula, which is what we all start thinking about when we think of Deep Sky objects and you want filters and lots of bits of kit and patience. But I'm also thinking what star clusters will be nice as these are beautiful objects are appreciate with binoculars, small telescopes or even naked eye. If you're lucky enough to have good low Bortle skies or live near a dark sky sight. It also helps if these classes are nice and high above the horizon. So because it helps keep them clear of light pollution and makes them easier to spot.

Ezzy Now you did mention low Bortle skies there. So for any of our listeners who haven't heard of that, the Bortle scale is a way of... quantifying, I suppose, how dark your skies are.

Charlotte So basically if you live in the middle of London or Japan, it would be like a Bortal 9 sky. Whereas if you lived in the middle of the Scottish Highlands, you may actually get like a Bortal 2 sky. That mythical low Bortal sky that we're all sort of craving and really, you know, we want to do our stargazing in. So yes, your low end of the scale, your pitch black dark skies on the high end of your scale are your city or urban skies. So on 20 and 21 February, M35 is a great cluster to see. So M35, that's the 35th object in the Messier catalogue. And these Messier catalogue objects comprise star clusters, planetary nebula, open or stellar nebula. So you can find M35 just west of the constellation of Gemini, and it'll still be pretty high at about 8 p.m. in the evening. Now it does have an apparent magnitude of just over 5 at 5.3, so technically it's within naked eye limits. But again, I've at least come prepared with some binoculars or I'd actually be tempted to pop a camera onto my telescope and take some pictures of this object. It's a lovely diffuse cluster, so not too tricky to pick up as there's lots of lovely bright stars in M35 and its diameter is about 28 arc minutes long, so there's just over 100 member stars. If you were to observe it or you are lucky enough to observe it naked eye, it would be a sort of fuzzy patch. You wouldn't really get too much sort of intricate detail, naked eye. That's what your telescope's going to be for. If you did want to take an image. The great thing about clusters is you don't need lots of really long exposures or overly sophisticated, you know, tracking equipment. It's a lovely beginner target. And so you can fire off a few short exposures and see just how many different star colours you can pick up there, which will help to denote the age of the stars within the cluster. On Wednesday, 22 February will be at the early stages of a waxing moon. They come around very quickly and on 22nd will be about 8% illuminated. So a lovely slim crescent. And if you look towards the west, southwest horizon, about an hour after sunset, we'll be able to see the Moon, Jupiter and Venus all huddled close together. And you won't be able to miss them as they're all beautifully bright and easy to spot. So this would be a lovely wide field nightscape to capture, as Jupiter will be about six degrees above Venus. And we typically say that the width of three of your fingers is about five degrees separation. So that gives you an idea of roughly how close they're going to appear in the night sky. And the Moon is going to be nestled nicely in between these objects. Three of Jupiter's Galilean moons will also be visible, all of them apart from Ganymede, which will be behind the planet at that night. So while you're out and about, it would be a shame not to also swing over to Mars, which would be nice and high in the Taurus constellation. And while it's moving away from us and is getting smaller and dimmer to our eyes, it will always make a nice sight when it is coupled close to older, barren and nearby Betelgeuse.

Ezzy We mentioned it on last week's show, but older Brain is a red star and Moses is red in colour as well. So it's always great to sort of compare those two. And Betelgeuse is also red as well.

Charlotte Absolutely.

Ezzy Three red things and you can compare those in the night sky as well to all of the sort of more familiar white and blue stars out there.

Charlotte I think also when you're when you are just starting out in astronomy, you don't always appreciate the sort of different colours you do get in these objects and then you think once you see them, it's hard to actually ignore how how sort of distinct they are in the night sky. And it's just makes them always quite nice to look out for. So it just really helps you to appreciate, you know, this sort of close grouping of these red objects or these ruddy orange objects are just going to look really stunning in the winter night sky, I think. So moving on to Thursday 23rd through to Sunday 26 February. Now the moon will be waxing again, as I've said, and it will be just under half illuminated at about 44% by 26th. But on 24th, the sun will set about just after 5:20, and a little over an hour later, at 18:45, we will see Jupiter and Venus once again low on the southwest horizon. But this time I want you to look towards the Moon in the southwest and then up to the Pleiades, which would be nice and high above the horizon at about 50 degrees. Now, draw an imaginary line between these two points and roughly in between, close to the southwest at about 44 degrees above the horizon will be Uranus. It's not as bright as these other sky hoggers such as Venus, but it's there. And it's a really nice way to be able to find it again. As I say, I love star hopping or finding other objects close to objects and so once you draw that line, it'll be a really nice way of locating this far away mysterious planet that we don't always get to see and appreciate. So as I say, it's not as bright and you will need to take some care in time. But this is a night where you will want to bring a telescope, as you will need this light gathering aperture to get the best out of viewing this. So keep your eyes peeled for a greenish dot to the southwest. As I say, about 40, I think it is just about 44 degrees above the horizon. And again, Mars will be higher up just beyond the Pleiades, over 60 degrees altitude. So you'll have this almost line of interesting objects to explore, starting from the slim crescent moon through to Uranus to the Pleiades, and then finally Mars. So I think that's another lovely little sort of composition to keep an eye out for this week, as we.

Ezzy With those dimmer planets, it is always useful to have something to point your way. So last week we had Venus pointing the way to Neptune and this time over towards Uranus, because they are, I believe I can never remember which one it is, but one of them is supposedly naked eye. If you've got very, very good eyesight and a very, very dark site.

Charlotte Yes. Yeah, exactly. I think actually is meant to be Uranus. Personal experience, pop a telescope out, I think. And I'd just let it work... Do the hard work for you.

Ezzy Yes. It's like maybe you can. See it with your naked eye, but probably not from anywhere in the UK. And also you'll have a much, much better view if you just look at it through a telescope.

Charlotte Absolutely.

Ezzy But it's always a good opportunity and I think it's always just a great excuse to look at the Pleiades, which is just a beautiful object any day of the week.

Charlotte It's stunning. Absolutely.

Ezzy So it certainly sounds like there's lots of really interesting things to see in this month's night sky. Starting on 20th we've got a new moon, which is going to mean we can see some of those really dimmer and deep sky objects, which is great because Comet E3 the Green Comet, is going to be moving through Orion this week. So I really can't wait to see some of the pictures that are going to come from that because I think those are going to be fabulous. If you do take any, please do be sure to send them in. You can find the details at www.skyatnightmagazine.com. We always love to see your photos. Then on 20th to 21st, you can take advantage of the dark skies to take a look at M35 which is a beautiful open cluster. Then on 22nd the Moon will be starting to come back. It will be a very thin crescent, joined by Jupiter and Venus. And if you're out and about anyway, you might as well also go and take a look over at Mars. Then on 23rd to 26th to finish up the week, Pleiades, the Moon and Mars are all going to be in the same area of sky and helpfully pointing your way to the dim planet, Uranus, which if you've never seen, it's always a great opportunity when you've got those bigger, brighter objects pointing the way. So hopefully you've seen something there that you would like to get out and see that this week if you did. We hope to see you back here next week. Please do be sure to subscribe. And Charlotte, thank you very much for joining us on the podcast today. It was great to have you. Hopefully we'll see you back again on the podcast soon. 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 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 Bramley 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.