Podcaster: Dr Jacinta Delhaize and Dr Daniel Cunnama ; Guest: Dr. Miriam Nyamai
Title: The Cosmic Savannah – Ep. 039: Erupting Novae
Link : www.thecosmicsavannah.com ; @cosmicsavannah (twitter, facebook & instagram) ; https://thecosmicsavannah.com/episode-39-erupting-novae/
Description:
In this week’s episode, we are joined by Dr. Miriam Nyamai who studies thermonuclear eruptions on the surface of white dwarf stars!
Miriam explains how these “novae” eruptions occur and what we can learn from them.
Miriam has just completed her PhD at the University of Cape Town. She is now working as a postdoctoral researcher hunting for transient events in the sky using radio telescopes such as MeerKAT.
Bio: Dr Jacinta Delhaize and Dr Daniel Cunnama are astronomers based in Cape Town, South Africa. Jacinta is a Research Fellow at the University of Cape Town. She spends her time using huge radio telescopes to study gas and black holes in distant galaxies. Daniel is the Science Engagement Astronomer at the South African Astronomical Observatory. He likes to use large supercomputers to create simulations of galaxies. Both Jacinta and Daniel love to promote the incredible astronomy happening across the African continent.
Dr. Miriam Nyamai is a postdoctoral researcher hunting for transient events in the sky using radio telescopes such as MeerKAT.
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Transcript:
[00:00:00] Jacinta: Welcome to The Cosmic Savannah with Dr. Jacinta Delhaize
[00:00:08] Dan: and Dr. Daniel Cunnama. Each episode, we will be giving you a behind the scenes look at world-class astronomy and astrophysics happening under African skies.
[00:00:17] Jacinta: Let us introduce you to the people involved, the technology we use, the exciting work we do, and the fascinating discoveries we make.
[00:00:25] Dan: Sit back and relax as we take you on a safari through the skies.
[00:00:34] Jacinta: Welcome to episode 39, everyone. Today, we are speaking with Dr. Miriam Nyamai from the University of Cape Town.
[00:00:41] Dan: And you spoke to Miriam right?
[00:00:45] Jacinta: Yeah. Miriam is working on studying thermonuclear eruptions, not thermonuclear explosions, thermonuclear eruptions.
[00:00:53] Dan: We do love a good thermonuclear explosion though. I mean, it sounds pretty dramatic.
I should point out quickly that I do have a bit of a cold, so apologies for the nasal sounding, or more nasal than usual.
[00:00:54] Jacinta: It’s not COVID though.
[00:00:55] Dan: It’s not COVID it’s just the beauty of having small children who make you sick.
So thermonuclear explosions. I mean, it sounds incredibly dramatic and it is, I guess.
[00:00:55] Jacinta: Yes. Thermonuclear eruptions though.
[00:01:21] Dan: Eruptions, oh, my apologies.
[00:01:22] Jacinta: qNo, I kept getting it wrong when I was speaking to Miriam. So she corrected me a few times. So what we’re talking about today is something called a nova, which is different to a supernova. It’s kind of like the precursor, the thing that comes before. And what it is is it’s a white dwarf, which is the evolved remnant of a star that’s similar to our sun.
So the sun will get old, will grow into a red giant, puff out, and then eventually it will let go of all of its outer layers. And what’s there in the end is, is the solid carbon core, which we call the white dwarf. But sometimes stars can be born in binary with another star. And when this happens, one star might turn into a white dwarf first, and then the other star will maybe grow into a red giant.
And when that happens, some of the material from the outer layers of the red giant can start to accrete onto the white dwarf. And that means that the layers are pulled off the red giant and sort of orbit around and then fall onto the surface of the white dwarf. But there’s kind of like a mass limit that goes on. And so sometimes these layers that are kind of getting accreted onto the white dwarf can suddenly erupt in a thermonuclear explosion. That’s called a nova. So that’s what Miriam was talking about.
[00:02:34] Dan: So basically the white dwarf is cannibalizing its brother or sister and devouring it’s outer layers.
And in that adds mass to the white dwarf which occasionally causes some eruptions of the surface, which we can observe.
[00:02:52] Jacinta: Yeah. So the outer layers kind of detonate a bit. And then yeah, we can observe these kind of quote unquote smaller eruptions. It’s not exactly cannibalizing. It’s just kind of like taking a sip of the outer layers.
But then what can happen is if it accumulates enough mass there… so there’s like these little, little novae. Well, they’re not that small. The smaller nova are going off, the eruptions, and then Miriam is studying these novae to figure out whether or not she thinks these systems are going to go supernova.
So these systems can explode in supernova explosions, but they are specific type called type Ia supernovae. And that means… it’s when the white dwarf itself completely detonates, the entire thing is destroyed. So when it gets, when there’s enough material from the red giant accreted onto the white dwarf, it can reach a mass limit called the Chandrasekhar limit. And when that. The whole white dwarf explodes and destroys itself in this type Ia supernova.
So Miriam was looking at different kinds of binary systems, three different systems, and figuring out whether or not she thinks they are going to explode. She calls these progenitors. So the white dwarf with the nova going to form, it’s the progenitor of the type Ia supernova.
[00:04:04] Dan: All right. Well, we probably shouldn’t steal all of Miriam’s thunder or thermonuclear eruption.
Um,
[00:04:16] Jacinta: okay. I’ll give you that one. Oh my goodness. Sorry, listeners.
[00:04:22] Dan: Yeah, let’s hear from Miriam and we can discuss more after.
[00:04:27] Jacinta: All right. Let’s hear from Miriam.
With us today is Dr. Miriam Nyamai from the University of Cape Town. Welcome Miriam.
[00:04:42] Miriam: Thank you. Thank you. Jacinta.
[00:04:43] Jacinta: Hi. Great to have you with us. Can you just tell us a little bit about you?
[00:04:47] Miriam: Right. So I am a SARAO postdoctoral fellow at the University of Cape Town. And I work as part of the ThunderKAT team.
I grew up in Makueni Kenya, which is in the Eastern province. It’s around a hundred kilometers from Nairobi on your way to Mombasa, which is a coastal city. I did my undergraduate degree in, at Kenyatta University in Kenya, and I did my post-graduate studies in South Africa at University of Cape Town and University of the Free State.
[00:05:20] Jacinta: Great. And you have just finished your PhD?
[00:05:23] Miriam: Yeah. Yes. I completed my PhD this year before I started the postdoctoral fellowship at the same university.
[00:05:30] Jacinta: Great. That’s amazing. What an amazing achievement. PhDs are just so hard to, you know, get across the finish line. So well done for getting there.
[00:05:38] Miriam: Thank you. Thank you. It’s indeed a difficult task. You have to have positive energy and you have to persevere.
[00:05:45] Jacinta: How did it feel?
[00:05:47] Miriam: It felt like quite a journey. It was not easy. Sometimes you feel like you can do this. Sometimes you feel like, ah, what am I doing? But in the end, if you keep going, you don’t lose hope, you just keep going. And in the end it feels very nice to finish, to complete, actually. It feels like a very good achievement.
[00:06:10] Jacinta: Amazing. So you haven’t actually had your graduation ceremony yet, so technically not doctor, but I’m going to promote you because by the time this comes out, maybe you already will be.
[00:06:20] Miriam: Absolutely. I’ve not done my graduation yet. But it’s coming up soon.
[00:06:28] Jacinta: Yeah. I mean, by the time you submit the thesis, you’ve already done the work, so you’ve already earned it.
[00:06:33] Miriam: Thank you. Thank you. That’s amazing.
[00:06:36] Jacinta: Yeah. Is there much astronomy happening in Kenya?
[00:06:39] Miriam: Yes, not much, but at least there’s a few groups that are really doing great work.
There’s one in Technical University of Kenya. That is led by professor Paul Baki. And then there’s Dr. Willis or Borneo who did his PhD at the University of Leeds in the UK. He is also a part of it, he’s very instrumental in the group. And there are also a few other people who are doing great work in Kenya. There’s Dr. Hashim, who is in Kenyatta University. He did his PhD in astroparticle physics and is supervising students in astronomy as well. So there’s at least something going on in Kenya and that’s just very encouraging.
[00:07:17] Jacinta: Wonderful, a growing community. What got you interested in astronomy in the first place?
[00:07:22] Miriam: To be honest, I wasn’t interested in astronomy. I was interested in mathematics. Yeah. Mathematics was my favourite from primary school to high school level to university level. I really liked mathematics, but when I heard about the National Astrophysics and Space Science program, which was hosted at the University of Cape Town, and about astronomy and astrophysics and space science.
So I got quite interested and applied for the program. And when I joined, I never looked back. I was like, this is amazing. I want to keep going.
[00:07:57] Jacinta: So you were hooked.
[00:07:59] Miriam: I was hooked. I was definitely hooked. And I liked the idea of observations with telescopes. I liked the idea of computer programming and I liked the idea of a physics and mathematics background.
Like it’s all coming together in one course. And that was amazing for me. That was the right jump.
[00:08:17] Jacinta: Great. So tell us a little bit about what was your PhD research about or what topic were you working.
[00:08:24] Miriam: So I was working on radio observations of thermonuclear eruption, to be specific. My PhD work was purely at radio wavelengths, and I got to use the MeerKAT telescope, which is in the Karoo in South Africa.
It’s an amazing telescope. I love it. And I also observed with the Very Large Array in New Mexico in the USA. So that was also a very good experience. I got to work with people and experts leading in the field. Professor Laura Chomiuk at Michigan State University. And I also worked with Dr. Valerio Ribeiro, who is based in Portugal. And I also worked with Professor Patrick Woudt, who is the HOD at the University of Cape Town Astronomy Department. They are amazing, very bright. They shared their wisdom with so much patience and I was grateful that I got to work with them.
[00:09:21] Jacinta: Oh, wonderful. So did you actually, you know, pre COVID times, did you actually get to go and visit these places?
[00:09:22] Miriam: Yes, I was in the U S Michigan. Yeah. 2018. And then I went to Portugal. Sorry. Portugal started fast. I was in Portugal in 2000 and I’m sorry, I got the, I think I got the years mixed, but I visited my advisors in Portugal in the us during the course of my PhD. And it was a very good experience.
[00:09:22] Jacinta: Oh, amazing.
You got to work with the VLA as well. The Very Large Array. How do you observe with that? Is it just online or do you actually have to go there to Soccoro.
[00:09:32] Miriam: The setup is very similar to the MeerKAT telescope. So you write a proposal and you request observations and they do the observations for you.
And then you get to look at the data. So it’s very similar to the meerKAT.
[00:09:46] Jacinta: All right. Awesome. And so what were you looking at? You said that you study thermonuclear explosions. Now, I don’t have any idea what that is. So let’s talk about that. Was there a particular object you were looking at or what were you observing?
[00:09:59] Miriam: Yes. So for my PhD, I looked at three thermonuclear eruptions. So explosions is a term that is used for the supernova. The supernova where the white dwarf, the compact object is completely destroyed. So that is an explosion. But an eruption…
[00:10:16] Jacinta: Sorry, if I could just interrupt you there to ask, so a white dwarf, this is the core of a dead medium-sized or small size star, right?
[00:10:24] Miriam: Correct. That is correct.
[00:10:26] Jacinta: And it can sometimes have a companion star, so it can be like a binary orbiting another star. Is that right?
[00:10:32] Miriam: That is correct. Yes. So you have a white dwarf, which is the compact object, it’s quite dense. And is sort of a dead star in quotes, like you said. And then it’s in close orbit with a secondary star.
Now for my thesis, I considered three types of… not types really. But I looked at three different types of companion stars. So I looked at a helium star, which was a companion of our compact object, a white dwarf. And I looked at a red giant, and I looked at a main sequence star. So thermonuclear options occur in all these types of systems.
And I looked at those three types of systems for my PhD.
[00:11:14] Jacinta: Okay. So what’s the difference between a main sequence star, a helium star and a red giant.
[00:11:19] Miriam: Right. So our main sequence star is not evolved. It’s a less, I mean, it’s not that evolved. It’s just a normal star.
[00:11:27] Jacinta: Like our sun, right?
[00:11:28] Miriam: Yes. Correct. And then a red giant is quite evolved.
[00:11:32] Jacinta: Okay. So this is like further on in its lifetime.
[00:11:35] Miriam: Yes. That is further on in his lifetime. Correct. And then a helium star, okay. So those two contain mostly they contain hydrogen, but a helium star does not contain hydrogen. It contains helium.
[00:11:49] Jacinta: Why doesn’t it contain hydrogen?
[00:11:51] Miriam: I think it’s more to do with the it’s evolution. The mechanism of evolution is slightly different from the hydrogen star. Yes.
[00:11:58] Jacinta: Okay. So a helium star isn’t dominated by hydrogen, it’s dominated by helium.
[00:12:02] Miriam: Correct.
[00:12:03] Jacinta: And then you said that all three of these companions can cause thermonuclear explosions for the white dwarf. How does that happen?
[00:12:10] Miriam: So it’s a very similar mechanism, not similar, but it’s the same. It’s only that they accretion, or the mass transfering process, is slightly different. But a thermonuclear eruption ocurs when the mass from the companion star is extensively accreted on the surface of the white dwarf.
[00:12:29] Jacinta: So stuff is being pulled from this companion star, the main sequence or the helium star or the red giant, onto the white dwarf. Right?
[00:12:38] Miriam: Correct. Yes. And when that happens, the material accumulates and as it accumulates the temperature and the pressure increases, and that increases the nuclear reactions. And when that happens, the nuclear reactions keep on increasing. Then there’s now what we call the thermonuclear eruption, where the outer layers of that white dwarf are expelled out into space. But the white dwarf is still there. It’s not destroyed. It’s just the outer layers that are expelled into space off the surface of the white dwarf.
[00:13:14] Jacinta: So stuff is falling onto this white dwarf. It’s pulling off material from the companion star. It’s all landing on the surface. It’s getting more and more and there’s thermonuclear reactions going on. And then all of a sudden it detonates, right. And the outer layers of the white dwarf are just blown off, blown apart.
[00:13:28] Miriam: Yes, correct.
[00:13:29] Jacinta: And this is the thermonuclear explosion.
[00:13:29] Miriam: Yes. That is correct. Yeah. That is how it happens, basically.
[00:13:37] Jacinta: And why is it interesting to look at that?
[00:13:39] Miriam: Right. So there’s very many things that I was interested in when I was studying these systems. But there are two things that I was mainly interested in and one is how to determine, I mean, the amount of the rejected mass or the amount that is blown off the surface of the white dwarf and number two is to try and study the mass loss mechanism of these systems. So either the mass loss or the accretion process, or the process in which the mass is pulled onto the white dwarf. So those are the three main things that encouraged me to look at these systems.
[00:14:17] Jacinta: Okay. And you looked at them with radio telescopes.
Why did you do that?
[00:14:21] Miriam: Correct. So I looked at them with radio telescopes. It’s because radio telescopes, of course they compliment the other wavelengths. Of course they’ve been studied in multiwavelength, but they compliment that. And one thing about the radio is that they give us the opportunity to study the emission mechanism.
So there are two main mechanisms that are often present in this system. There’s the synchrotron emission and the free-free emission. And if you model the free-free emission from these systems, then you can determine the amount of mass ejection from the white dwarf. If you’re studying the synchrotron emission from these systems, then you can determine the mass loss. How the mass is lost from the companion star.
[00:15:06] Jacinta: Okay, so there’s two types of radio mission coming from the system. So if you look at one of those types, you can detect how much mass was lost from the white dwarf. And then if you look at the other type, you can study how much mass was lost from the big companion star and like, accreted onto the white dwarf. Right?
[00:15:26] Miriam: Correct. That’s correct. Yeah.
[00:15:27] Jacinta: Okay.
[00:15:29] Miriam: The reason we are interested is because the connection between the thermonuclear eruptions and the type Ia supernovae, is those two things. The rate of accretion, the rate the mass is pulled onto the white dwarf and the amount of mass that is ejected from the white dwarf after the thermonuclear eruption. So it’s the link between the two.
[00:15:50] Jacinta: Okay. And this is what determines whether it is, or it isn’t classified as a type Ia supernova.
[00:15:56] Miriam: Correct. Yes.
[00:15:57] Jacinta: So as it is at the moment, why isn’t it already a type Ia supernova?
[00:16:02] Miriam: Okay. So there are some clues why it can be but I think we are still looking at it. We still looking at the links. We are trying to see if the white dwarf can still maintain enough mass to grow in mass.
Because it has to grow to what we call the Chandrasekhar limit.
[00:16:23] Jacinta: Okay, so what is a type Ia supernova?
[00:16:25] Miriam: So a type Ia supernova, it’s an explosion, a thermonuclear explosion, that destroys the white dwarf completely.
[00:16:33] Jacinta: Ah, so you’re saying that these thermonuclear eruptions, they’re just like little detonations going off on the top of the surface of the white dwarf.
And so this system could be a progenitor, meaning something that is going to evolve into a type Ia supernova, which is when suddenly there’s so much mass built up on the surface of the white dwarf that it detonates so violently that the entire white dwarf is destroyed.
[00:16:59] Miriam: Correct.
[00:16:59] Jacinta: Okay. So these a little thermonuclear eruptions, they’re kind of like the death warnings of the white dwarf.
[00:17:08] Miriam: Yes. Warning us. Can it be, can it not be? Yes.
[00:17:11] Jacinta: Okay. Okay, cool. So you’re looking at these systems with radio telescopes. So what did you find?
[00:17:18] Miriam: They were quite interesting. I found that there’s a lot to study. So I got an opportunity to determine the mass loss, the amount of mass that is ejected from one of the systems.
Then I estimated the amount of mass that is lost from the companion star for another system. And then for the helium nova, I got to determine that the mass loss in the helium nova is not as straightforward as people think. So there are clues of complexities in the mass loss of the system.
[00:17:49] Jacinta: Okay. So things were fairly straightforward for the system where the companion star was a main sequence and where it was a red giant, but it was a bit more complicated when there was a helium star, right?
[00:18:01] Miriam: So they were sort of straightforward where the companion star was the main sequence. There were a few clues where the companion star was the red giant, it was also not that straightforward. There’s complexities there, but there’s definitely more complexities for the helium nova, when the companion star was was the helium nova.
Yeah.
[00:18:23] Jacinta: And why do you think that is?
[00:18:26] Miriam: I think we need more computational or hydrodynamic simulations to be able to give more insights in that. Because I did more observations. My PhD was mostly observational. But I think the hydrodynamic simulations using our results, they can even uncover more on what’s going on there in the mass loss.
[00:18:50] Jacinta: Okay. So you found that there’s…you found something new. You found that this system is more complicated than we thought, which means that when we’re trying to simulate the system, so like reproduce it in a computer, there’s more complicated physics that we have to introduce in order to reproduce the system.
And so this is telling us that there’s new physics to be discovered, right?
[00:19:09] Miriam: Absolutely. Absolutely.
[00:19:11] Jacinta: Wow, cool!
[00:19:14] Miriam: Yeah, it was very cool.
[00:19:15] Jacinta: How did it feel when you found that?
[00:19:17] Miriam: It was very exciting. Actually, for the one system where we have the white dwarf and the helium star, it has been published in Monthly Notices. Astronomers tend to link the helium nova with type Ia supernova. But I think we first need to see the complexity of the mass loss before that can be simulated. So I’m really looking forward to those type of simulations. So that was very exciting.
Yeah. And then for the red giant – white dwarf binary system, we also noticed that there’s also complexities in the way the mass loss is happening. So I’m also looking forward to that as well.
[00:20:00] Jacinta: Okay. So you’re going to be working on following up both of those systems.
[00:20:05] Miriam: Yes. Yes. I will definitely work on following up on those. I mean, I’m really excited that people are doing a dynamic simulations on that. So that’s really exciting to see how it unfolds.
[00:20:18] Jacinta: Okay. Cool. So you’ll be following that very closely, I’m sure.
[00:20:22] Miriam: Absolutely
[00:20:23] Jacinta: Yep. And what else are you doing as part of your postdoctoral research now at the University of Cape Town? Is it the same work or is it slightly different?
[00:20:31] Miriam: It’s a combination. So it’s thermonuclear eruptions with MeerKAT. At the moment we are closely following a nova, a recurring nova, which is a white dwarf and a red giant that went into outburst again.
[00:20:44] Jacinta: Oooh!
[00:20:45] Miriam: Yes, with MeerKAT. With Professor Patrick Woudt as well. So that is very exciting. It went off again 15 years ago in February, 2006. And has gone off again in August, 2021.
[00:21:01] Jacinta: So is it actually quite rare for us to see the same object go nova more than once?
[00:21:05] Miriam: Yes.
I think it’s rare. There are just a few that have been studied and this object has been studied quite extensively. And it’s very interesting. Everybody, I mean, people are really interested in it. So I’m looking forward to what MeerKAT is going to do for these objectives. It’s amazing.
[00:21:24] Jacinta: So it was found, it went off again earlier this year, was it?
[00:21:27] Miriam: No, no. It went off on Sunday last week.
[00:21:30] Jacinta: Woah!
[00:21:34] Miriam: It went into an eruption this Sunday and we got some MeerKAT observations. We have some results at the moment. It’s really exciting.
[00:21:43] Jacinta: Oh! Hot off the press! This is amazing!
[00:21:47] Miriam: It is. So I do thermonuclear eruptions, like that system. I’m now trying to venture into radio transients with ThunderKAT. They have a very amazing working group there. So I’m looking forward to that.
[00:22:03] Jacinta: Wonderful. So what’s ThunderKAT and what’s a transient?
[00:22:06] Miriam: I think you’ve talked about before. So ThunderKAT studies radio transients, basically. Where something appears in the sky or it’s visible and then it’s not. But then they focus on studying these transient at radio wavelengths. But I’m very sure you’ve covered this in your podcast before.
[00:22:30] Jacinta: Yes, we’ve talked to Patrick Woudt, who’s one of the PIs of ThunderKAT. And we’ve spoken to Michelle Lochner who also works on things related to transients at the Vera C Rubin telescope. And, ah, great! So you’ve just gotten on board with looking at transient.
How do you search for a transient? Do you like, just look at the data and compare it from one day to another?
[00:22:53] Miriam: Yes, that is basically it. Of course there is statistics involved. You look at one image that was observed, like for example, today. And another day you compare those two and see if there’s variability in the radio. And then if there is variability, then you can follow up with other wavelengths or you can monitor it for a long time.
[00:23:13] Jacinta: So, yeah, I was just going to ask, what do you do when you find
something new?
[00:23:17] Miriam: So you monitor it for a long time. See what type of variability it is. If it’s days or years or months. Or you could also look at it with other wavelengths and determine what it is. Because radio transients are very new.
So not much is known about radio transients. Some of the radio transients are not even identified what they are. So you could do a multiwavelength study to see what exactly is this type of system. And then once you do that, like, what I do is I do modelling then to determine other physical parameters. Because when a radio transient goes off, then there’s a lot of energy that is released into the universe.
So that can give us an opportunity to study that phenomena, which we don’t know.
[00:24:06] Jacinta: Okay. So we’ve got lots of things, kind of like bursting in the sky, which we’re picking up with radio telescopes. Some of them get bright and then faint and then bright and then faint again. Some of them just are bright and then go away forever.
And so you’re saying that we’ve only just recently found out that there are radio transients and we don’t really know what each of them are. So that’s part of the fun, right?
[00:24:28] Miriam: Yes. Yes. And then the fact that big telescopes are coming up, there’s the SKA coming up. So I’m very sure they will pick up a lot of those.
Some of the radio transients are fairly known. I think like the AGN. I’m very sure you know what’s an AGN. I think that’s your field.
[00:24:45] Jacinta: Yes, yes. We have talked about active galactic nuclei before. So radio galaxies with black holes in the centers.
[00:24:52] Miriam: Yes, I think mostly it’s those. But there are other new phenomena that big telescopes or modern telescopes, like MeerKAT are picking up and we don’t know yet what they are.
So that’s very exciting. And the more you do, the big surveys, the LSPs, the more they look into into the universe, the more we tend to find these systems. So it’s an exciting time.
[00:25:16] Jacinta: Wow. That’s so exciting! Yeah. Well, awesome. Thank you, Miriam. Is there, before we go, is there anything else you’d like to talk about or any messages you have for our listeners?
[00:25:29] Miriam: All right. So I think I’ve really been lucky to study at the University of Cape Town and to do a lot of international collaborations. So I think if some people or students are interested in astronomy, in science, I think if somebody gets an opportunity, then they should go for it. It’s very exciting with the new telescopes coming up.
I am very lucky to work with MeerKAT and I’m looking forward to the SKA.
[00:25:57] Jacinta: Yeah. Things in Southern Africa are getting pretty exciting in radio astronomy.
[00:26:00] Miriam: Yes. Yes. They are.
[00:26:03] Jacinta: Awesome. Well, thank you so much, Miriam for joining us. And if our listeners would like to follow you, are you on social media anywhere?
[00:26:09] Miriam: Yes, I am on Twitter and I’m on Facebook. Twitter I think it’s Miriam MN. And same as Facebook. My user name is Miriam MN. I upload a lot of science stuff as well. I’m also on Instagram.
[00:26:23] Jacinta: Wonderful. Cool. So we’ll put the links to those on our website for this episode.
[00:26:28] Miriam: Okay. Thank you.
[00:26:30] Jacinta: Okay. Thanks for joining us, Miriam. It’s great to chat with you.
[00:26:33] Miriam: Thank you for having me.
[00:26:42] Dan: Thank you for that. I mean, the first time I heard it, so very interesting. And I get the feeling, we talk about binary stars quite regularly. And I mean, do you have any feeling for how common binary systems are?
[00:26:57] Jacinta: I think that they’re actually the most common. I think that the sun is a bit of an anomaly, that it’s much rarer for a star to be on its own. I wonder if that was a factor of life forming here? I don’t know how life forming in a binary system would be different to single.
[00:27:17] Dan: I guess the one thing about these binary systems and while we do observe them so regularly and study them is that they are pretty active.
They’re doing these little eruptions and sometimes they go supernova and whatever. They’re quite.Dynamic and interesting systems. Whereas a star like our sun is pretty boring, really.
[00:27:41] Jacinta: Yeah. I mean, again, that, I think that’s sort of like why we exist is that we have a very stable environment. Our sun doesn’t do anything fancy.
Our star is quite, you know, inactive really. So I think it would be difficult if you were on a planet living around one of these binary star systems. You’ll have, you know, one of them grows older before the other one. So you’ve got this red giant problem where, you know, the temperature is going to change and the star might even gobble you up.
And then even if you survive that, then you’ve got these eruptions going off all the time. These nova where, you know, stuff is getting pulled onto one of your dead stars and, you know, havoc is going on all the time, it would be very hard for life just to chill for a while there.
[00:28:26] Dan: We digress, but we’ve spoken about exoplanets before. But we should find someone to talk about how life evolves.
[00:28:33] Jacinta: Yes. Clearly we don’t know much about that. So we should, we should do that.
[00:28:37] Dan: Maybe not how life evolves, but how astronomically life evolves.
[00:28:40] Jacinta: Yeah, exactly. We did speak with Ewine van Dishoek in Episode 20: Cosmic Chemistry. She speaks a little bit about finding the molecules that can eventually produce life.
And Miriam also talks about transients, just to jump topic again. So she works with the ThunderKAT survey on the MeerKAT telescope. And we did hear about that in Episode 23, when we talked to Professor Patrick Woudt, who is the PI of that project.
So if you want to learn more about that, you can check out Episode 23. And of course, Episode 37, the one that came before this, we spoke with Michelle Lochner, all about transients as well, but more with the Vera C Rubin optical telescope, rather than MeerKAT. And how she uses AI to try and study these sorts of things.
[00:29:29] Dan: It was pretty cool. I mean, we’ve spoken about ThunderKAT before, as you said, and the idea with ThunderKAT is to pick up these transients. So it’s not an observational campaign like you do when you want to study a particular galaxy or a particular patch of sky. ThunderKAT is looking for things that go bump in the night all the time.
And as, you know, Miriam mentioned, she observed something just the other day. And so you’re getting kind of, live feedback with this kind of work.
[00:29:58] Jacinta: Yeah, that was so cool. Like hot off the press. I mean, our lifetimes are so short compared to what’s going on in space, that it’s really exciting to see the same object go nova twice in one lifetime. You know, these things are going off, quote unquote all the time, but on longer timescales than we can observe. So this is actually really unique and really cool to be able to see it.
[00:30:23] Dan: That’s great. And also just to mention, great that we are, are getting astronomy growing. She mentioned a little bit about astronomy in Kenya and how it’s not very big. But training up people from around the continent who often I think will go back and grow that astronomy in their home countries. I’m not sure where Miriam will end up or would like to end up, but there is a chance that she ends up back in Kenya and the astronomy community in Kenya
grows.
[00:30:53] Jacinta: Yeah. Shout out to all our Kenyan listeners. I know we’ve got a few, so hello to you all. Well, I think that’s it for today. It’s like a short, sharp and shiny episode. So thank you very much for listening and we hope you’ll join us again for the next episode of The Cosmic Savannah.
[00:31:10] Dan: You can visit our website thecosmicsavannah.com. We we’ll have the transcript, links and other stuff related to today’s episode.
[00:31:17] Jacinta: Follow us on Twitter, Facebook and Instagram @cosmicsavannah. That’s Savannah spelled S A V A N N A H. Special thanks today to Dr. Miriam Nyamai for speaking with us.
[00:31:30] Dan: Thanks to our social media manager Sumari Hattingh. Also to Mark Allnut for music production. Jacob Fine for sound editing, Michal Lyzcek for photography, Carl Jones for astrophotography and Suzie Caras for graphic design.
[00:31:44] Jacinta: We gratefully acknowledge support from the South African National Research Foundation, the South African Astronomical Observatory and the University of Cape Town Astronomy Department.
[00:31:53] Dan: You can subscribe on Apple Podcasts, Spotify, or wherever you get your podcasts.
And we’d really appreciate it if you could rate and review us and recommend us to a friend.
[00:32:02] Jacinta: We’ll speak to you next time on The Cosmic Savannah.
[00:32:04] Dan: Do you think we got a sufficient blooper in there? Or do you want to say something ridiculous?
End of podcast:
365 Days of Astronomy
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