Mini Episode 3: The Most Powerful Explosion Ever Recorded

with Reikantseone Diretse

Hosted by Sumari Hattingh

In our third mini episode, we chat with Reikantseone Diretse, a Master’s student from the University of Cape Town. He is involved with the ThunderKAT (The HUNt for Dynamic and Explosive Radio Transients) project. This project is a large program on the MeerKAT telescope. It studies extremely bright and energetic explosions in our sky, which are known as transients.

Part of Reikantseone’s research involves one particular transient event. It is a gamma-ray burst that was recorded in January 2019. This very rare explosion is the most powerful gamma-ray burst that has ever been recorded to date. Its radiation is almost a trillion times more energetic than that of visible light!

Reikantseone’s studies are funded by the Institute for Data Intensive Astronomy (IDIA). His passion for astronomy reflects not only in the various projects that he is involved with. He also serves as the president for the Space Society of the University of Cape Town.

This week’s guest:

Reikantseone Diretse at the IDIA Visualisation Lab. The green circle in the background indicates the MeerKAT observation of the most powerful gamma-ray burst ever recorded: GRB190114C.

Featured Image:

Artist’s expression of gamma ray-bust GRB190114C, the most energetic transient ever recorded. Gamma-ray bursts are the result of stars that collapse and eject matter into the sky at extremely high velocities. The energy of these powerful gamma-ray bursts are measured in electron volts (eV). One electron volt represents the energy that a single electron gains when it is accelerated by one volt. The afterglow for most gamma-ray bursts is measured in giga-electronvolts (GeV). But GRB190114C was detected at a trillion electron volts (TeV)!

This mini episode is hosted & produced by:

Sumari Hattingh (Centre for Space Research, North-West University):

Mini Episode Transcript

Transcribed by Sumari Hattingh

Sumari: [00:00:00] Welcome to The Cosmic Savannah. To each and every listener, this would be my very first mini episode as a trainee for The Cosmic Savannah. I’m Sumari Hattingh, and I’m currently in my second and final year of Master’s studies in Astrophysical Sciences at the North-West University. I met Dr. Jacinta at an Astronomy Data School that took place in Cape Town during October, 2019.

After she has told me more about The Cosmic Savannah, I was absolutely hooked. I keep learning so much from all the astronomers around the world who share their research and work here on The Cosmic Savannah. So in today’s mini episode, I have the privilege to chat with Reikantseone Diretse and learn more about his work, what all his research is about and what he does.

He is a second and final year Masters student as well, and he studies at the University of Cape Town with funding, from IDIA. IDIA is the Institute for Data Intensive Astronomy. This is an inter-university partnership of three South African universities; that of Cape Town, Western Cape and Pretoria.

IDIA’s goal is basically to build capacity and expertise in data intensive research and large survey science projects within the South African university research community. So Reika’s current Masters research involves working with the ThunderKAT project. If I remember correctly, it’s episode 23 of The Cosmic Savannah, where professor Patrick Woudt – Head of Astronomy at the University of Cape Town was interviewed about ThunderKAT, which is The Hunt for Dynamic and Explosive Radio Transients with MeerKAT.

In short, this large program on MeerKAT aims to study accretion of very compact binaries. When referring to compact binaries, it means that there are two astronomical objects that are very close together and in orbit with one another. These objects are very dense and can either both be compact, like two neutron stars or two black holes, or it can be a binary system of one compact and one massive object, where the massive object can be a red giant star.

So whether a compact binary system have two compact objects or one massive and one compact object, when they interact a collision takes place causing massive explosions, also known as transients. Next, particles and matter are then ejected into space at exceptional high velocities.

Reikantseone’s research is then about one particular transient event: a gamma-ray burst that was recorded in early 2019. In this specific case, the massive star – part of a compact binary system – dies. The result is then a very rare explosion, far away from earth known to be both very bright and extremely energetic. And with energetic, I mean that such a gamma-ray burst releases as much energy in a few seconds as the Sun will in its entire ten billion year lifetime.

Let’s hear more about Reika’s passion for astronomy, his involvement with an international campaign and his presidency of the Space Society of the University of Cape Twon, and what it entails.

Music playing

Welcome to my interview session. Today, I’m interviewing Reikantseone. Hi, how are you today?

Reikantseone: [00:04:29] Hello, Sumari! I’m great, how are you yourself?

Sumari: [00:04:31] I’m great, thank you very much. So I’m very excited for what we will be learning from you today. Before we begin, I would actually like for us to do as this-or-that icebreaker. So how it works, I will give you two options and you choose your favorite outloud; the first one that comes to mind.

Summer or winter?

Reikantseone: [00:04:51] Summer

Sumari: [00:04:53] Optical astronomy or radio astronomy?

Reikantseone: [00:04:57] Radio

Sumari: [00:04:58] Coffee or tea?

Reikantseone: [00:05:01] Tea, definitely tea! I’m literally having a cup of tea right now. Rooibos, half a teaspoon sugar, no milk. Always.

Sumari: [00:05:08] Oh, that sounds great. So last question: python or a C programming?

Reikantseone: [00:05:15] I wouldn’t like oppose C or anything, but I’m mainly trained in python and much more comfortable to work with python.

Sumari: [00:05:22] I think let’s start off with you introducing yourself. Can you please tell us where you are from and where you are currently studying?

Reikantseone: [00:05:30] So I did, my undergrad at the North-West University in Mahikeng – where I was born and raised. I did my Bachelor’s degree in Chemistry and Physics, and then I competed that.

And then I moved to the University of Cape Town with a scholarship from the South African Radio Astronomy Observatory to study for my Bachelor’s Honours in Astrophysics and Space Science. And while I was working on that degree, I got an internship to go work in Australia for 10 weeks, which is like two months and two weeks, with the Commonwealth Scientific and Industrial Research Organization.

So I was there working with the Parks Telescope on pulsars, and that was such a wonderful experience. I am now registered for my Masters – on to the second year – with UCT of course, and my funding is generally through the IDIA program. And then I’m working on a thesis, full research masters.

Sumari: [00:06:28] Wow, that sounds amazing.

I can just imagine how your journey must have been from traveling – from where you were born and where you’re studying now and going to Australia. I’m so excited for what we can here from you today. So tell us about your Master’s research.

Reikantseone: [00:06:45] Okay. So my Master’s research is probably one of the most exciting things I’ve ever done.

I am working with the ThunderKAT project. I’ve been working with the ThunderKAT project since my Honour’s. So the ThunderKAT project is generally The Hunt for Dynamic and Explosive Radio Transients with MeerKAT. So we have data coming in from MeerKAT, studying exciting projects, exciting sources in the sky where these explosions – whether it’s, things colliding onto to each other, whether it’s radio jets, et cetera.

It’s amazing. So for my Master’s research, I am working on gamma-ray bursts and I’m actually studying one particular gamma-ray bursts that happened last year, January, which was the most energetic gamma-ray burst ever, recorded from Earth.

Sumari: [00:07:31] Okay. So if you say it has been the most energetic gamma-ray burst ever recorded before, what does that exactly mean?

Reikantseone: [00:07:39] Okay. So gamma-ray bursts in general are generally the most luminous explosions in the universe anyway. They have really high energies and associated with very distant galaxies. So if you can see something extremely bright or extremely luminous from a very long distance, it means that it must have been so energetic that you were able to see from where you are.

So they are gamma-ray bursts and then they are generally emitting the initial lighting, the gamma rays, and hence high energy astrophysics. And then with this particular gamma-ray burst, it was the very first gamma-ray burst whose energy was recorded in the tera-electron volts. We normally use two energies being recorded in that mega electron volt.

And the previous highest was at like 90 electron giga-volt. And now this was beyond that – up to one electron tera-volt – so it’s like very much energetic because it’s literally a trillion times more energetic than visible light. So that is what we mean by it – energetic gamma-ray burst.

Sumari: [00:08:42] I think it must be amazing working with this project and being part of this amazing discovery; part of our history.

So what’s other astronomy projects are you involved in.

Reikantseone: [00:08:55] So as part of my Master’s, apart from working on gamma-ray bursts, I am also part of the deeper, wider cluster campaign, which generally is associated with, I suppose I run the multi-wavelength follow-up or studies for any transients in the sky that are happening.

So last year we were collaborating with people around the world – Machester, Australia, and then we were studying a few fields, three fields. And we are still doing the data analytics and it has been such a wonderful journey, learning different skills and everything. So I’m very much pleased and very, very much privileged to have been part of this amazing project.

Sumari: [00:09:34] You said you’re involved and ThunderKAT which, getS observations from MeerKAT. So have you ever been to the SKA site based in the Karoo, Northern Cape of South Africa? And can you tell us about your experience if you have been there?

Reikantseone: [00:09:50] Oh no, unfortunately I have not been to the Northern Cape. Well, I’ve been to the Northern Cape a thousand times, but I haven’t been to SARAO, to MeerKAT in particular.

And I know that we also have like programs and projects, for people to go there, but I used MeerKAT, data from MeerKAT. I have observations taken for me, by the staff there. And then they send it to IDIA, which is a computing infrastructure at the university. So I have data coming from the MeerKAT and I have been working on that for this gamma-ray bursts that I’m working on for over a year now, because I had observations since last year, January until this year, January.

So it has been amazing. But unfortunately I have not been to MeerKAT yet.

Sumari: [00:10:33] I think it must be pretty exciting to look forward to the day that you can visit the site. So do you have any other interests in astronomy, apart from your research?

Reikantseone: [00:10:46] Absolutely. I am currently a president for the UCT Space Society, where we have astronomers giving lectures and talks to the public – well, mainly to the society members so that every student – whether in astronomy or not – they can get to understand and to learn some of the amazing things that we work on as researchers, we also do stargazing as part of the society.

After every lecture, we will do a stargazing event. And then this year for the very first time we introduced rocketry, where we people from Jo’burg coming in from space research, come in to teach students how to build rockets, and then we launch them on the second day. And we also do planetarium tours, which have been fantastic, but we only did one before the lockdown happened.And then with the current pandemic, we are doing social media engagements on Instagram, Facebook and Twitter. So that is as far as it goes with astronomy to the public.

Sumari: [00:11:44] Then I would like to know, how does your future in astronomy look like? What are your plans for next year?

Reikantseone: [00:11:52] Well plans for next year. Hopefully to start working on a PhD project, hopefully with ThunderKAT again, because ThunderKAT generally studies amazing projects, anything about radio transients and explosions. And there is the science that fascinates me – the high energy astrophysics itself, or astrophysical sources out there. So anything that just goes bang, that is where my interests lie.

So whether it’s fast radio bursts, gamma-ray bursts or whether it’s X-ray binaries. Whatever the case may be because there’s so much exciting things happening in the night sky on a daily. So I would really much like to work on a PhD project with ThunderKAT moving forward, because it also gets me to work with MeerKAT.

And that is amazing because we have a fantastic tool. So we might as well use it brilliantly.

Sumari: [00:12:36] I really hope for your part, that you can continue your journey with ThunderKAT and that you will be able to start your PhD as well, because that would be really exciting for another part in your life.

Then I would also like to know, can listeners find you on social media?

Reikantseone: [00:12:54] Yes, I am definitely on social media. I am on Instagram: at-reikantseone . I am on Facebook: Reikantseone Diretse. Twitter: reikantseone-d and those are all my social media platforms, but followers can also search for the UCT Space Society – we are very much engaging with our followers on that platform to make sure that as much people can get to know about astronomy and everything we do – the science that we do in South Africa and the outside.

Sumari: [00:13:24] That is great because I think it’s very important that not just the society and communities get to know astronomy better, but also understand why we do the work that we do.

Thank you very much, Reikantseone. It was really nice talking to you today, and I hope you have a great day.

Reikantseone: [00:13:40] Thank you so much for having me a Sumari.

Music Playing

Sumari: [00:13:49] Wow, what an exciting journey Reikantseone has, he’s such an all-rounder; part of multiple projects and just has this energetic vibe that makes me so excited and intrigued to learn more about gamma-ray bursts. It blows my mind to think that he has the key to work with data from massive explosions in galaxies that are so very far away from us.

Just something about the detection of these bursts: after an initial flash of gamma-rays that take place: a longer-lived afterglow is usually emitted at longer wavelengths, such as x-ray ultraviolet, optical, infrared, microwave, and radio.

So why is all of this important? I mean, these transient events are so far away – some of them only last for a few milliseconds and some of them can last for several hours. But why and do we even need to study events like these? Well, not only has the sky been a navigation system to humans throughout history, we all look up to the sky at some point and think, what is that little bright sparkly dot and what does it do? Or me way even ask why does the sky like different throughout the year? Maybe we even read about astronomy events on news apps of our smartphones, and think, why has this event been studied and why do we even need to know more about what’s out there?

You know, there can be so many different answers and opinions about this, but I can assure you, astronomy is very important for us to help better understand our universe and how it works. We can learn more about the elements in the cosmos; how it all came together. But also, by investing in research, science education and even technology, it gives us as a population so much more in return than one would realize. We learn more than the day before. We expand our knowledge and network by developing plans to give the world a better view of our Universe.

I leave you, the listeners, with Ahmed Zewali’s quote: “Preserving knowledge is easy. Transferring knowledge is also easy, but making new knowledge is neither easy nor profitable in the short term. Fundamental research proves profitable in the long run, and as importantly, it is a force that enriches the culture of any society with reason and basic truth.

I would like to thank Dr. Daniel Cunnama and Dr. Jacinta Delhaize for giving me this amazing opportunity to do this mini episode with Reikantseone Diretse.

And also, thanks to you – the listener – who joined in and supports The Cosmic Savannah throughout. That’s it from me. Goodbye.