A ‘new’ star is expected to appear in the night sky any day, as recurring nova T Coronae Borealis is due to flare up once again. Every 70 to 80 years, the star’s brightness jumps, making it naked eye visible for a few days. Find out where you should be looking for the nova and other stargazing highlights in this week’s Star Diary podcast, 24 to 30 June 2024.
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Chris: Hello and welcome to Star Diary, the podcast from the makers of BBC Sky at Night Magazine. You can subscribe to the digital edition of the magazine by visiting iTunes, Google Play or Apple News, or to the print edition by visiting skyatnightmagazine.com.
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 BST. In this episode, we'll be covering the coming week from 24 to 30 June. I'm Ezzy Pearson, the magazine's features editor and I'm joined by Mary McIntyre, an astronomer and astronomy writer.
Hello, Mary.
Mary: Hi, Ezzy. It's great to be back.
Ezzy: Thank you for coming back. So what do we have to look forward to in this week's night sky?
Mary: Well, this week we're still fighting against the twilight and not really getting a true darkness at the moment across the UK, but we do still have some planets to spot.
We've got some lunar conjunctions and clair obscure effects, a couple of comets. A diamond solitaire at the North Pole and also noctilucent cloud season continues.
So we'll start off with the planets and we cannot see Venus and Uranus this week, so they're out of the picture. Most of the other planets are actually in the morning sky still.
So Saturn, currently at mag +1.0, lies in Aquarius and that is rising at about 1:00AM so it's still a little bit dark where I live then. Neptune, mag +7.8, so you'll definitely need binoculars or a telescope to spot that. That lies in Pisces and is rising about 1:30 in the morning. That is definitely going to be a challenge to see in the twilight, but if you have binoculars just look that way and see if you can spot it.
The great thing about looking at the planets that are faint like that is it makes you learn the starfield. So you kind of get familiar with what the stars look like through binoculars, then you can see the faint planet or asteroids moving through the starfield.
Ezzy: If you're trying to use a constellation to help you find a planet, then you do sort of need to know what the constellation looks like. But it's a good way to learn.
Mary: They look very different through binoculars. There's a lot more stars.
Ezzy: Yes, I find that sometimes. There's a very familiar constellation and then I go from my very light polluted city where I live to a dark sky site and I look up and it's like, "Oh! Orion looks different tonight." Because there's just so much more going on.
Mary: Yeah, it can actually be hard to spot the fainter constellations when you're in too dark a sky. It's, uh, it's crazy.
Ezzy: I can see the Orion Nebula. What's going on?
Mary: Mars currently lies in Aries and is rising at about 2:15AM. When I say about, it's because depending on your latitude and longitude, the rise times are very slightly different, but these are a kind of ballpark figure for the UK.
So Mars is currently mag +1.1. At the beginning of the week, it's rising about 2:15AM. It's rising about 15 minutes earlier by the end of the week, which is better. It gives you a little bit more chance to spot it, but it is going to be difficult to see in the twilight.
But it will be easier to see than Jupiter, which is currently mag -2.0, but it's not rising until 3:15 in the morning, which means it's going to be incredibly difficult to spot in the twilight. The magnitudes are kind of not a reliable figure when you're looking at it in a sky that's about to have a sun rising in it, so do keep in mind that although the quoted figures are quite bright for these planets, they are going to be hard to see in the twilight.
In the evening this week, if you are very, very lucky, you might spot Mercury. It's going to be incredibly low in the northwest after sunset. Again, mag -0.7, but really very, very challenging.
It lies in Gemini and it's setting at about 10:30PM. So it's going to be very low and very hard to spot, but it will get a little bit better as the next couple of weeks come on.
Always worth looking for Mercury. It's always low over the horizon anyway, because it just can't get high in our sky because of where it is. But definitely worth kind of keeping an eye out for that to see if you can spot it.
One that you will need binoculars for is dwarf planet Ceres. That is going to be opposition next week.
So Ceres is near the handle of the teapot this week and it rises at about 10:30 in the evening, reaches its highest point at about 2:15 in the morning. So have a look at near the handle of the teapot with binoculars and it's at around mag +7.3 so it's definitely achievable in binoculars.
Certainly a simple wide field. Set up like photography wise, you'll be able to capture it.
Ezzy: There's a reason why asteroids and such weren't found immediately after the invention of the telescope. It took a couple of years because they're not the brightest things. And they keep moving as well, which is very... well, that's how we find them and how we know what they are. But does make them a bit more difficult to track down in the first place.
Mary: It does, and I think it's rewarding when you do spot them and see them moving against the background stars. I love them. They're just a little dot on my picture, but I'm very fond of them.
Moving on to the Moon this week, we're passing from an almost full phase through to last quarter. Last quarter Moon is on 28 June.
On 27 June, the waning gibbous Moon is to the right of Saturn, so you can use those to find each other.
On the 28th of June, it is moved over to the left of Saturn. So again, just demonstrating that the Moon is moving at a different pace to all the stars and the planets.
So they're playing this kind of game of cat and mouse all the time, and it's always interesting to see just how much the Moon is moved each day.
On 29 June, the 46% waning Moon has a few clair obscur effects to look for. First of all, at 2:00 in the morning, we have The Cutlass, which is where light reflects off Rupes Recta, and also a little bit below that, and it gives the impression of a curved cutlass handle and a blade. So, look for that one.
We also have at seven o'clock in the morning in a daytime sky, Curtis's Cross, and that is where sunlight is kind of bouncing off Frau Maruo Zeta complex on the Moon, so you can find that at 7:00 in the morning.
And then definitely in a daytime sky we have at 11:00 that morning the Star Tipped Mountain, which is where the sunlight is capturing the top of Mons Herodotus. So the way that that mountain has such a sharp peak, the way the sun hits it kind of gives it its name, the Star Tipped Mountain.
That one is harder to see in a daytime sky but all these clair obscur effects are fun to look for. They're always very transient. We don't get to see them every month from the UK.
So I like to try to track those down.
Ezzy: It is always a bit odd when you're giving people stargazing advice for the day. But sometimes you can see things in a day. There's the odd time you can see the odd planet. Venus quite famously can be seen in the daytime sky sometimes. The Sun obviously has to be up in the daytime sky and that's always a popular one.
We were talking about that last week, the Sun is very active at the moment, so it's definitely worth looking at that if you can. But just because the days are long doesn't mean there's not things that you can look up in the... I was about to say the night sky again, just out of habit, but the day sky.
Mary: Yeah, there's a reason I kind of started to get interested in clouds, because sometimes that's all we get to look at, and it gives you something to look for all the time if you start getting into that as well.
Ezzy: And astronomers always, you know, there's a famous... well, not so much love-hate relationship, just hate-hate relationship with clouds for a lot of astronomers because they block out the view.
But I like that attitude. You can't get rid of the clouds, so just learn to love them.
Mary: Yeah. I mean, if you've got thin cirrus clouds, it can give you a whole array of atmospheric optical effects, which are stunning. And I'm just ever so slightly obsessed with ice halos and arcs.
I get so excited when I see something that's quite unusual. And at this time of year, actually talking about atmospheric optics, it's our only time from the UK that we have the opportunity to see the circumhorizon arc.
They're quite rare from here because the Sun has to be above 58º in order for it to form, and it's even then very close to the horizon because it's 44º under the Sun, but the Sun has to be higher than that for it to form. And it's just where light is refracted from ice crystals and it causes this absolutely beautiful, straight, horizontal rainbow, essentially.
It just looks like a straight rainbow underneath the Sun. Colour separation and horizontal bands and they are gorgeous. There are lots of things to look out for in the summer like that as well. Learn to embrace the clouds because they're not going anywhere. We live in the UK.
Ezzy: And also, you know, sometimes if you're taking a picture of something like the Moon, especially because it's so big and bright, there's, atmospheric pictures of that with the clouds in front of it.
Sometimes it can look a bit like it's a Halloween card. It's a little bit spooky. But it can also give it like this ethereal glow. So just because there's clouds about doesn't necessarily mean skygazing is off the table.
Mary: Yeah, I mean, low level cloud around the Moon gives you those bands of colour called a corona. They just look beautiful. There's like orange and blue and turquoise. How can you not love that? I mean, it's just gorgeous.
We have a couple of comets to look for this week. They're not spectacular but definitely worth looking for.
13P Olbers is technically visible all night. Well, it's above the horizon all night.
Your best bet is to have a look for it after sunset, as soon as it gets dark. It's moving through Lynx, and by the end of the week, it's only 16º above the northwest horizon at 11:15PM. But that is doable. 16º above is doable. With comets you kind of have to just make do with that quite often because they are low when they get near perihelion.
It will be a challenge in the never ending twilight. It's due to reach perihelion on 13 June, so then it's predicted to reach about mag +5.0. So the peak magnitude is actually going to be a couple of days later on 2 July but it's going to be around about that magnitude all week, so it's worth looking out for.
It will, although technically +5.0 is naked eye, you're not going to see it naked eye in the twilight sky, so you will need binoculars. But definitely worth looking for.
C2023 A3 Tsuchinshan-ATLAS is currently in Leo. That is visible after sunset at the beginning of the week. It's about 11º above the horizon, above the west southwest horizon at 11:15PM. It sets at about 12:30, so you need to get out there before midnight really to try to spot that. By the end of the week though, it's going to have sunk to about 6.75º. Earlier this week is definitely going to be better to try to spot that one.
It's currently around about mag +9.4, that's where it is on its predicted light curve. It may reach peak brightness in October and it's due to be definitely naked eye observable. But I never make any assumptions with comets. Whatever the light curve says, they will do their own thing.
But in theory, it's going to reach almost mag -1.0 by the time we get to October, so there's a lot of people watching this comet right now.
On 25 June, that comet actually lies within a chain of galaxies below Leo, so if you're looking through binoculars, you may think, wait, why is there an extra galaxy here? I love a deep sky comet conjunction, so it will be a beautiful photo opportunity if you do astrophotography.
But even through binoculars, if you can see some of the brighter galaxies in that chain, you'll spot the little fuzzy blob of the comet nearby.
Ezzy: I think that's one of the things that people forget quite often is that when you're looking at these, quite often galaxies and comets can look very similar.
In fact, one of the most famous catalogues of... not just galaxies. Galaxies and nebulae, the Messier catalogue, was made because an astronomer was trying to make a list of things that weren't comets so that when he was going around and he found like, "Oh, there's a fuzzy blob. No, it's that thing that's been there."
And then people came along with more powerful telescopes that could resolve things a bit better. And they realized, "Oh, wait, this is actually something interesting, and we should pay attention to it."
Mary: I often say I'd love Messier to come back and look at the Messier posters now because he had no interest in those objects whatsoever.
He just was interested that they were not comets, and I'm like, would he change his opinion if you could see what they actually were?
Ezzy: It is one of those things I also want to see, how would he react that his name is tied to the thing that he didn't care about? It's not the thing that you spent ages trying to find, it's the things that it wasn't that.
Mary: Yeah, I think it'd be great for him to come back and actually see that.
There's another interesting thing to look for this week, and actually all month. If you look with binoculars at Polaris, you will notice that Polaris is not alone. It actually sits within a little circlet of stars.
They're all around about magnitude +8.0 or +9.0. So they do need binoculars to see them, but they form a little circle with Polaris looking like a diamond in a diamond solitaire. So it's like an engagement ring around the celestial pole.
And this is another one of those things that I'd photographed so many times and hadn't realized that I had it. And it's a really pretty little thing to look for in binoculars.
A really good time to look for that when the Moon is kind of last quarter, once we've got a bit of darkness before the Moon rises. Just have a look then, it'll be your best chance to spot those stars.
Noctilucent cloud season is continuing, we have had confirmed sightings, so make sure that you are looking along the northern horizon about an hour after sunset or an hour before sunrise.
Sometimes at this time of year they can be visible all night long if you get a really good display. But they kind of have this glowing quality about them that is really beautiful and definitely worth getting up early to try to spot them if you haven't seen them before.
The International Space Station, if you like spotting the space station, that is returning to our skies in the early hours of the morning.
There are some really nice passes this week by the time we get to the end of the week on 29 and 30 June and it's going to be back in our. sky for a couple of weeks, so definitely get out and have a look for those passes. There's more than one a night, there's usually one that is brighter than the others and gets higher than.
Click here to find out how to find the International Space Station in the night sky
But I love spotting the space station and you know, just to see this bright light moving across from horizon to horizon and think there are people there. I just love it, I love it so much.
I have a hatred for the satellite constellations, but there's something really special about the space station.
Ezzy: I understand the difference there is, definitely. There's a bit more of a human connection when you know there's people actually up on there, going about their daily lives, maybe having a nap.
Probably not. They tend to be very busy up on the International Space Station. It's like every single minute is blocked out of what they're going to do.
Which is just, I can't live my life that way, which is why I'm not an astronaut. One of many reasons I'm not an astronaut, let's face it.
Mary: There's one last thing I want to talk about briefly, and this may or may not happen this week, but there is a star called T Corona Borealis.
That star is a recurring nova. It's a binary star. One of them is a white dwarf, the other is a red giant. The red giant is shedding off material, and the white dwarf is accreting that material. And when it reaches a critical mass, the star it just suddenly brightens and has this kind of explosion of light, essentially.
So it's not a supernova, this is a recurring nova that happens in a cyclic manner.
This star is about 3,000 lightyears away. It last did its brightening in 1946. Usually a sign that it is ready to kind of flare up again is that the star starts to get a little bit dimmer first and it started to get dimmer in March 2023 .
It's predicted that any time between now and September this year that that star is suddenly going to go from being mag +10.0 to naked eye visible about the same magnitude as Polaris.
It's not going to give you like a bright extra Moon in the sky or anything like that. But it is really awesome to just go out and take a picture of Corona Borealis tonight.
Ezzy: Absolutely. Yeah.
Mary: Just be ready because when you see this nova, there will suddenly be a new star in Corona Borealis and it is always amazing to actually photograph those.
Ezzy: And when it does actually go nova, you will be able to just walk outside at night and be able to see it, provided Corona Borealis is up in the sky at the time.
It is one of those once in a lifetime things. What was it that you said every 70 or 80 years it's supposed to happen?
Mary: So yeah, it's about every 70 years that this happens, and so we know it last did it 1946, so yeah, we're all Waiting for that to happen.
I actually photographed Nova Delphini a few years ago and also Nova Cas.
Nova Cas was an interesting one because that was a new nova that wasn't expected and I had just by complete coincidence had been photographing Caroline's Rose, a lovely cluster named by Caroline Herschel. And I had the progenitor star in that image, so I was able to do a little animation showing it 3 days before it had been discovered.
So I actually had the progenitor star, incredibly faint, totally the wrong equipment to have been doing photometry but I was actually able to do photometry on that for the first time ever. Don't ask me how to do that because I can't remember now. But you know, I downloaded the software crash course on how to do photometry and it fitted with the predicted light curve when they marked it backwards.
So yeah, it's always good fun to see these things. And remember Tycho Brahe actually noticed a nova. And it made him realize the stars were not the distance away everyone thought they were. So there's a colorful history with them. We've even got petroglyphs, haven't we? There was a nova in Scorpius that's depicted in a petroglyph in Arizona.
Ezzy: Ah! I hadn't heard about that.
Mary: Yeah, people have observed novae for years and nova literally means new star. I always think it's amazing when we get to see those.
Ezzy: Yes, we do have an article online about it. We also get quite a few people who've been emailing in recently. If anybody at home would like to email us with any questions, please do. It's at contactus@skyatnightmagazine.com.
When the nova does eventually go off, we'll It will be bright for a good couple of days. I think it's going to be naked eye visible for a good couple of days and then will remain visible in binoculars and telescopes slowly fading away.
So it's not going to be just like one bright flash and then it's done. It's going to be around with us for a couple of days.
Even if you miss it on the day when it actually happens, there will still be opportunity for you to go out the next couple of nights as well.
So keep an eye on the news. I'm sure it will actually probably break through into main news I think when it happens. It's a new star. It's incredibly exciting.
Mary: There's already been quite a lot of mainstream attention on this with extremely misleading stuff about a massive explosion and kind of implying it's a supernova when it isn't. So it is exciting and it already has made mainstream media so yeah it will definitely be reported when it happens.
Ezzy: Certainly lots of things to keep an eye on, even when you are out and about. But you can certainly keep an eye out for T Coronae Borealis whilst you are looking at all the other things that are in the night sky this week. And thank you very much, Mary, for taking us through all of those.
If our listeners at home would like to find out even more stargazing highlights and keep up to date with what's going on in the night sky, and the day sky sometimes, please do subscribe to the Star Diary podcast.
But to summarise that week again:
Unfortunately we are in the middle of the summer so the twilights are quite long which means that the nights might not be getting fully dark where you are, but that doesn't mean there's not lots of things to see.
Most of the planets this week are in the morning sky.
Saturn will be rising around 1:00AM, Neptune around 1:30AM, Mars will be rising at 2:15AM at the beginning of the week and 2:00AM by the end. And Jupiter at around about 3:15.
Those last three will be difficult to see, Neptune is difficult at this time of year, and Mars and Jupiter will both be difficult to see in the twilight.
We do have one evening planet. Mercury will be very low in the northwestern sky after sunset. It will be setting out around about 10:30PM and staying very low to the horizon. We also have the dwarf planet Ceres, which will be at opposition this week near the Teapot asterism.
In terms of the Moon, Saturn and the Moon are going to be close to each other on 27 and 28 June.
Then on 29 June, we have a trio of clair obscur effects to take a look at. We have The Cutlass, which will appear around 2:00AM.
Then at 7:00AM in the daytime sky, Frau Mauro Zeta Complex.
And at 1:00AM the Star Tipped Mountain as well.
In terms of comets, Olbers is going to be technically visible all night, but it will be best after sunset, moving through the constellation of Lynx. And it will be low in the sky as it will reach perihelion this week, its closest approach to the sun, on 30 July.
Comet Tsuchinshan-ATLAS will be visible after sunset in Leo. Might be naked eye observable by this point in time, we hope. And if you look for it on 25 June, you will find that it is close to several galaxies. In fact, if you are looking at those galaxies, you might see a smudge there and wonder what that is. And it will be Comet Tsuchinshan.
The Polaris Engagement Ring will be visible throughout the week, but is probably best viewed toward the end of the week when the Moon is out of the way.
NLC season continues, so keep an eye out for those after sunset and before sunrise.
For those of our listeners in the UK, keep an eye out for the ISS passing overhead in the early hours of 29 and 30 June.
For people overseas, if you want to keep up to date with what the ISS is going up to, I will post a link in the show notes below about how you can work out where the International Space Station is, or you can find those over on our website.
And finally, throughout this week and in fact the coming months, keep an eye on T Coronae Borealis, a star which is expected to jump in brightness as it is a recurring nova that is due to brighten any day now.
So lots of things in the night sky to keep your eye on and we hope to see you back here next week to find out even more things to see. From all of us here at Sky at Night Magazine, 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 pull out 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, there's 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: Thank you for listening to this episode of the Star Diary podcast from the makers of BBC Sky at Night Magazine, which was edited by Lewis Dobbs. For more of our podcasts, visit our website at skyatnightmagazine.com/podcasts or head to Spotify, iTunes, or your favourite podcast player.
Listen to next week's episode "Jupiter’s moons form a triangle (Star Diary, 1 to 7 July 2024)"
