Astrophiz169: Dr Laura Driessen ~ Radio Stars

Note: FULL TRANSCRIPT BELOW

Listen: https://soundcloud.com/astrophiz/astrophiz169-dr-laura-driessen-radio-stars

I am really excited to be speaking again with Dr Laura Driessen, who is now recognized as one of Australia’s Superstars of STEM!

You first met Laura 5 years ago back in 2018 when she was doing her PhD at the University of Manchester and Jodrell Bank.

Laura’s back story is all there in Astrophiz Episode 54. You heard about her obsession with space starting at age 4 and her natural yet meandering academic Astro journey up to the point where she was using commensal searches on the MeerKAT array in South Africa for pinpointing and localization of FRBs, Fast Radio Bursts. 

Today we’re taking up that story from where we left off, and we hear of her first post-doc with the CSIRO in Perth, her FRB and Radio Star research and her outreach work in the outback with indigenous school kids who live near the iconic Murchison Widefield Array and the ASKAP Array. 

Laura tells us about her current research and her work as the joint Science lead on the VAST project and you will love the clarity of her description of the power and nature of Commensal Searches, and how she uses archival data to verify that her radio data is actually coming from her targeted star and not from a radio galaxy hiding behind it.

Another gift Laura gives us is her brilliant explanation of how scientists establish and maintain collaborations both big and small, and how scientists often begin with a large number of hypotheses to explain observed phenomena and how the null hypothesis is such a powerful tool in developing an accurate understanding of our universe.

Laura’s website is AstrolauraDOTcom … On social media you’ll find Laura, she’s @AstroLauraD on Twitter.
And her non-astro work can be found on Etsy at Oomigoomi ….. and her Whippet dog is astro.the.whippy on Instagram

AUDIO TRANSCRIPT:

Brendan: Welcome to the Astrophiz podcasts.

My name is Brendan O’Brien, and we’d like to acknowledge Australia’s first astronomers, the Aboriginal and Torres Strait Islander people, the traditional owners and custodians of the land we are on. This episode is produced on Yorta Yorta and Gardigal land, and we’re asking you to influence your local politicians with the message that we really need to change our energy policies and move to renewable energy sources to mitigate the effects of climate change.

And each month we love bringing you two fabulous episodes … on the first of each month, our friend, molecular Pharmacologist, Toxicologist and Amateur Astronomer Dr Ian ‘AstroBlog’ Musgrave brings you his monthly SkyGuide with all the essential observational highlights for telescopers, astrophotographers, and naked-eye observers.

Ian also includes ‘Ian’s Tangent’, where he takes us on a short journey of Astronomical Wonder!
In the middle of each month we bring you an exclusive and in-depth interview with a noted astrophysicist, astronomer, particle, physicist, radio telescope engineer, data scientist, or space scientist.

So right now we’re going to zoom up to Sydney, Australia to meet a wonderful astrophysicist who you first met five years ago when she was completing her PhD at Jodrell Bank, and now she’s back in Australia and into her second postdoc, doing more beautiful research into transients and radio stars, and she has some great stories you’ll really love.
So, hey, let’s catch up right now with Dr.Laura Driessen.

Brendan: Hello again, Laura.

Laura: Hi Brendan. How are you?

Brendan: Very well, thanks Laura …  and I’m really excited to be speaking with Dr. Laura Dreissen again. We first met her five years ago, back in 2018 when she was doing her PhD at the University of Manchester and working at Jodrell Bank. Since then, she’s done more travelling and more fabulous research, and now she’s back over in Australia’s east coast at Sydney.

First up, Laura, congratulations on winning your doctorate Dr. Laura, and for recently being awarded as one of Australia’s ‘Superstars of STEM’ …  and thanks for speaking with us again today, Laura.

Laura: Thanks Brendan. And I was really excited to get your email because the last time we chatted was the very beginning, only couple of months into my PhD … So lots of things have changed since then and I’m excited to chat.

Brendan: I can’t even imagine the changes … Okay. Before we talk about those recent adventures and your research discoveries, we’ll remind our listeners that Laura’s backstory is all there in Astrophiz Episode 54 from March 2018, where we heard about her obsession of space starting at age four, and her natural yet meandering academic astro journey up to the point where she was at Jodrell Bank and doing her PhD at Manchester Uni where she was using commensal searches on the MeerKAT array in South Africa for pinpointing and localization of FRBs aka ‘fast radio bursts’.

So today we’re taking up that story from where we left off, and I can’t wait to hear it all. So, Laura, Can you tell us about Dr. Driessen’s first Postoc position with Australia’s Premiere Science organization, the CSIRO  … and your move back to warmer climes.

How did you land that position and where were you based? Who did you work with there and what research did you focus on over there In Perth Western Australia?

Laura: Sure. We probably have to go a little bit into the PhD as a sort of start of the story of how I ended up at CSIRO .

Um, so where we left off is that I had just started my PhD and I was working on localizing FRBs and I did keep working on that.

But in the meantime as well, Professor Ben Stappers, who was my PhD supervisor, managed to convince me that ‘radio stars’ were also something interesting to look into.

And I have to say that it was a little … I took a little bit of convincing. As a radio astronomer, we don’t typically think about stars at all.

You’ve interviewed quite a few radio astronomers and we tend to look at, you know, explosions, supernovae, x-ray binaries, black holes, galaxies … And stars don’t typically make the list.
So when Ben first said, “Let’s have a look at Stars” so I sort of went, “Oh yeah, sure…. You know, Radio stars’.

But eventually I came around because it turns out they’re really interesting  … and nobody’s really looked into them in detail since about the eighties or nineties.

Now because of these commensal searches we can do they’ve sort of come back into fashion a little bit. Mainly because it was hard before with the telescopes we had that can only see a small bit of the sky to say, “Hey, give me 20 hours to point at this star” … and maybe we’ll see nothing at all. That’s not particularly convincing when you’re asking for telescope time.

Brendan: Yep.

Laura: But now we have MeerKAT and ASKAP … and all those telescopes that can see a big chunks of sky. So I can take the data on stars that just happen to be in the image, so nobody was pointing at them, but they’re there anyway, so I can grab that information. So it’s really had a big leap in stellar radio astronomy.

And that’s really how I ended up at CSIRO. They posted a job and I sort of went … “Actually that’s pretty much like that job description was written for me”  … because the job was to look at radio stars and investigate how uh, radio emission from stars might affect the planets that might be orbiting those stars. So I sort of went “Oh, it’s in Australia … even better!”

Now since the pandemic, you know, plans change and, I thought maybe being in Australia for a little bit wouldn’t hurt.

So I went over there to Perth. Four weeks before the Melbourne Football Club Grand Final. And I have to say that I sat in the front row behind the goals because it was just excellent timing … me being a diehard Melbourne supporter. So that was pretty good. So I was over there in Perth and working on radio stars, but still working on FRBs as well cause I can’t help it.

Brendan: Yep, FRBs are pretty cool. Fantastic! Yay demons! … Okay, so you are over there in Perth and you are obviously not far … just three or 400 kilometers away from ASKAP and the Murchison Widefield array. Did you do some work on ASKAP and did you get out to see any of those beautiful radio telescopes in remote Western Australia?

Laura: Yes, I’m very lucky that I, uh, switched a little bit from MeerKAT to ASKAP coming over to Australia, which makes sense since it is our very own Australian SKA Pathfinder, uh, telescope out there in the Murchison about eight hours drive from Perth, or four hours from Geraldton, if you are familiar with that part of the world?

Brendan: Yep.

Laura: It’s out into the fair dinkum Outback of Australia, the middle of nowhere in the truest. So yes, I’ve switched a little bit, well, I work a bit on both, but to ASKAP searching for these stars, uh, and also as part of the VAST collaboration, which I think we’ll talk about in a little bit. And yes, I was incredibly lucky to go out to see the telescopes.

I was invited out by Dr. Rob Hollow, who’s the C.S.I.R.O Education and Outreach person who goes out there about once a year, pandemic allowing, to share our science with the remote school in the Murchison. So that’s really exciting for us because we use those telescopes out there in the Murchison at Elgar Bunara, the C.S.I.R.O’s Murchison Radio Astronomy Observatory.

And it really means a lot to us to be able to give back to the community and say, this is what we are doing with these amazing telescopes. So I got to go out there and spend a day with the amazing school kids. Out there at the remote school, um, and talk about the stars that I find and how I find them and get to see the telescope.

So not many of us get the privilege to go and take photos of, of ASKAP, but I was lucky enough to get to do that as part of sharing that with the community out there.

Brendan: Ah, well fantastic. And those kids would be blown away by seeing lady scientists and hearing what’s happening on their, on their own land. That’s so beautiful … Now you mentioned the VAST Project. Now we have just mentioned VAST about five episodes ago. Can you give us a skinny on the VAST Project you are the Joint Project Scientist. Perhaps you could introduce our listeners to the VAST Project, it’s purpose, it’s methodology, and tell us about your VAST responsibilities  ….. and how’s it all going Laura?

Laura: It’s going great. I’m happy to report. So far we’ve really only started doing the full survey, so exciting times in the future, but VAST is the Variables And Slow Transient survey with ASKAP.
I’d probably rename it something else …  ‘Slow Transients’ just doesn’t sound quite so fun as what we’re doing, does it, so we’ll just call it VAST instead.
It’s a Commensal project … So we’ve used that word a few times and that basically means looking at all the sources that we see with our telescope rather than just pointing the telescope at one usually really cool thing. So with a commensal survey we’re just pointing at the sky to see what we can … and we have our own observations where we choose, where we point the telescope, as well as just taking any observation with ASKAP.

The beautiful thing about ASKAP is that all the data are publicly available as soon as possible, so that means that we have agreed with the other teams that we all get to have a look, but also we can just grab the data as it comes out and see what we see in there. But the main purpose of the VAST survey is to do roughly 15 minute observations and just repoint the same part of the sky over different times.

So there are parts of the sky that every two weeks we grab a 15 minute snapshot of. And there are other parts of the sky that, you know, we might wait a couple of months to have another look and it’ll go over, I think it’s four or five years. I should know that off the top of my head. That we’ll just keep looking at parts of the sky with no particular object.

We’re not saying we look at that spot because there’s this particular thing there. We’re just going, that’s a patch of sky and we’re gonna see what changes over time. So the purpose is to see anything that suddenly comes into existence and, and becomes booming and bright, or things that change in brightness over time, or even things that maybe disappear. So we are looking for the things that change in the radio sky on all sorts of time scales. From the shortest we can do. 10 seconds is the shortest image we can make up to the full few years of the observation. So we’re looking for things that change, and as part of being joint Project Scientist with Dr. Dougal Dobie who’s at Swinburn Uni … we sort of have an overview of what everybody’s doing. So we’re really only ramping up now, and my most of my duties … sort of organizing the monthly meetings so that we can keep track of what everybody’s doing and the exciting things that are coming out. But as things ramp up and as we start doing all of our observations, which as I said, we only really started doing part of the full thing a couple of months ago.

We’re gonna start having people coming forward and proposing things that they wanna do with our data. And it’s gonna be my job to keep track of what everybody’s doing and making sure we’re all working together nicely … so we don’t get to have 10 people trying to work on the same thing, and we actually get those 10 people working together instead.

Brendan:  Fantastic! Now this is quite accidental. That’s a lovely segue into the next question I’ve got for you, Laura. So career astrophysicists like you contribute to a great number of different collaborations all over the globe, and that’s how most big science is done. And really no one’s hoping for some lone genius beavering away in a lab somewhere to come up with a next big scientific discovery.

Now, as you’ve just alluded to, we know that many early career astronomers listen to our episodes. So for them … can you tell us how scientific collaborations are formed? How do the scientists come together to join and propose and contribute to collaborations? So how do you all share and organize that data and your analyses? … I hope you don’t use email. Is it all tied up with funding?

Laura: Yeah, so collaborations are really a key part of what we do. And as you say, none of us are really sitting in isolation just doing science. It just wouldn’t work because I don’t have that humongous skillset. I really need other people to help me out so we can actually get to the goal that we’re trying to achieve.

So we definitely aren’t sitting all alone. Less so even now that the pandemic is a little bit lessened, it looks a little bit differentto how it did a couple of years ago where a lot of us were sitting alone, not by choice, but we’re all connected still with lots of Zoom meetings. And ‘Slack’ is really our main method for quick collaboration chats.

I think interestingly in radio astronomy, just from what I’ve observed, I haven’t set up any big collaborations myself, but just from my observations …. Collaborations in radio astronomy tend to be around the telescopes that we use. So someone will be part of setting up a telescope, say 10 years before the telescope is even built, and they’ll work out, you know, what are the specs of that telescope, what is it gonna be able to see, have some ideas about the science that can be done, and then they’ll gather some people together.

Usually it’s a couple of senior astronomers who get together with a vision of what they can do with the telescope. And then they start building that collaboration, adding post-docs, other senior scientists bringing their PhD students in. So when the telescope is ready to go, they’re ready to use the telescope to achieve that hopefully big goal that they’ve originally thought about.

So a lot of the big collaborations, at least in radio astronomy, are focused around the telescope. So VAST is one example … ThunderKAT Team, which I’m in … another is MeerKAT which is sort of a similar thing, but not quite the same as VAST. We’re also doing Commensal Searches and investigations of image plane, radio sources.

Yep. So I think just from what I’ve observed, it’s typically one of the ways collaborations are built  around telescopes. But of course the other way is … a nice senior astronomer gets a big pot of money. They start to build their own team again around a specific science goal, and they get that team working together. So that’s like MeerTRAP, the ‘More Transients And Pulsars’ team that I was in ….  led by Professor Ben Stappers.

He got an ERC Horizons 2020 Grant and then built a team around that. But there’s also the other nice way, which I think is sort of a serendipitous scientific collaboration where you might … might have a, a Zoom chat or a conference … or you just meet up someone at the university and you start to have a chat and you go, “Oh my goodness! We could do something really cool together.”

And those tends to be sort of … a little bit … maybe smaller collaborations, but those can be really fun where you’ve just realized that you could do such really cool and interesting together. And I think those are also nice because they often bridge the gap between different types of astronomy … Rather than always having a big group of radio astronomers, which is fantastic.

You also might wanna have the other option where you actually might chat with an optical astronomer or something, someone who’s maybe a physicist or something like that, to maybe a little bit of a smaller goal, maybe one or two papers instead of a big five year collaboration. But those are also really fun to do and make that connection sort of in real life rather than a big planned thing.

So there’s a few different ways and I think it’s good to keep an eye out for all of those different ways and don’t be afraid to join collaborations often it’s as easy as sending an email and saying, “Hey, I work on this. I really like to join your team” … and help contribute to that particular topic.

For our data, we, we don’t typically share data via email cuz our data is typically gigabytes and sometimes even terabyte in size. So most Outlook servers aren’t really gonna handle that particularly well. We tend to have access to external computers. So someone, somewhere, say in Sydney, Prof Tara Murphy might have some machines that the data is stored on.

And then we all access it and do our analysis on there … so that we don’t have to be copying data all around the country or even all around the world. So that’s for, for data and analysis. Typically we don’t ever try and bring things onto our own laptops if we can help it … Coz the data is really big.

And even with the best laptops these days, they’re not really equipped to handle multiple radio images that are all very large files and try and do some analysis with that. So we typically use external computing facilities. This isn’t super-computers though. Sometimes we might use super computers. These are just smaller ‘mini’ super computers that we typically use, which are linked up together.

We do use email to send each other plots and, and generally maybe more formal things where we’re saying ‘The paper is now ready, please have a read of the draft’. That might be an email. But usually Slack is our typical messaging system, and that helps us because we’re all in different time zones and sometimes, you know, you just can’t respond immediately.

So having those text chats really helps us collaborate without having to get up at 2:00 AM for a Zoom call. So that’s how we typically have a chat when we are just chatting to each other and going, “Oh, did you see this in the data? This is really interesting. What do you think about that? Do you think that looks, looks like something real or just an artifact?”

That’s the sort of thing that we’ll chat in Slack instead.

Brendan:  Fantastic. Thanks Laura. You were talking about data there. I’m hoping to interview Greg Sleap the Data Scientist who managers the Pawsey Center.

Laura: Oh that sounds really fascinating. Yes, absolutely. And the Pawsey is one of our key facilities of course for using ASKAP … and where we do a lot of our work and where a lot of the data is stored and processed. So it would be really great to hear that cuz it’s a, a key facility for Australian Radio Astronomy.

Brendan:  Yep. Cool … Thanks. Laura. I mentioned earlier that you’ve done some great FRB research on MeerKAT, and you’ve reiterated that since the first Lorimer Burst was discovered in 2007, we’ve now detected hundreds of FRBs and we have some repeating FRBs

And we now know, well, thanks to some of your work, exactly where some of ’em are located, but the big mystery still remains. How close are we to understanding the mechanism or cause of FRBs? Are we looking at more than one mechanism? And I did see a paper yesterday in Nature, which showed a correlation between FRBs and gravitational waves emanating from a neutron star merger.

And we know that correlation doesn’t always mean causation. What’s the latest thinking on the mechanism or the cause of FRBs Laura?

Laura: I think this is such an interesting question because I think we’re a little bit closer and I think we’ve … we are always with this kind of scientific method when we see something and we can’t quite explain it.

In astronomy, we can’t do a nice experiment and say, “This is our hypothesis. Let’s test it.”
We just have to wait and see what we see and see how it all adds up. Or really subtracts, because that’s typically how this works. We have a whole bunch of theories. Then we see an FRB that does something in particular and we go, oh, well that cuts out these 10 theories because they can’t possibly explain what we just saw.

And then we’ll see another 10 FRBs and go, “Oh, well that cuts out this theory” … until hopefully we eventually have one theory that we weren’t able to cut out. So it’s more of a Null Hypothesis approach, sort of … And then cutting that null hypothesis out until we … until we find the one that still remains in the end.

And that’s why of course, science is always changing because then we might have the same hypothesis that’s happy and working for 10 years, and then someone else comes in and goes, “Did you know? I had another thought.” And this becomes a new theory that we have. I think there’s still a big question about whether there’s more than one mechanism or if there’s just one mechanism that is responsible for repeating and non-repeating FRBs.

The best analogy I think is the history of GRBs  … gamma ray bursts.

Brendan: Yep.

Laura:  … And how that theory sort of evolved. And I think we’re seeing a similar path that FRB theories are taking … and that in the end, GRB people did work out that it is kind of more than one mechanism for GRBs, more than one type of GRB and more than one mechanism responsible for them … And I don’t think I would be surprised by that. I think it would be, they’re kind of related mechanisms. They’re not too extremely different, but you can’t use Occam’s razor … it is not the best way to go typically … Because nature is strange … The universe does weird things … and there are usually a few ways that you can make similar flashes of light.

I think we’re still leaning towards Magnetars. That could just be because a lot of FRB astronomers are also Pulsar astronomers and we all have a bit of a soft spot for Magnetars cuz they’re very cool. But maybe a magnetar in a weird environment … Magnetars just doing strange magnetar things.
I think that’s still the preferred theory.

If you asked an FRB astronomer, you know, that’s probably the one that’s, that comes up the most and is still remaining at this point.

I think the paper you’re talking about is probably the one by Dr. Clancy James and his student Alex. That was really exciting stuff that they saw that there could be a link between one particular FRB and a gravitational wave.

I think it’s important to note here, and that the authors also acknowledged that this is one of those tantalizing sort of hints. So rather than being Cold Hard Evidence that these two events were linked  … the gravitational wave and the FRB. It’s more one of those things that you go, “Ooh, we’re gonna keep an eye on that!”

Because that could be something really, really interesting. So it’s extremely exciting to see even that hint that these things might be linked together and it, it definitely doesn’t go against any of the theories that we have that it’s actually neutron star mergers that could be responsible for one-off FRBs.

Of course, it’s difficult once your neutron stars have merged to create more than one. It’s like a supernova can’t go off multiple times, so that does sort of go lean towards the one off rather than a repeater. So it’s really exciting to see these tantalizing hints and, and hopefully once all the gravitational wave detectors are online and we can, they can localize their RBS a little bit better … that will help us to get more of a handle on whether these things truly are physically linked rather than just that, “Ooh, let’s have a closer look, because that could be really interesting and exciting!” So there’s still a lot of mystery going on in the world of FRBs … and that’s what makes it so exciting.

Of course, we still haven’t localized that many FRBs. It’s in the 10’s. Whereas we’re getting CHIME, the Canadian H1 mapping experiment is getting hundreds of FRBs per year.

Brendan: Yep.

Laura: Possibly thousands cuz they’re a little bit ‘hush hush’. So there’s still so much to find out, which is just so exciting.

Brendan: Fantastic! And that’s a beautiful explanation. That link between hard astrophysics and astrophysics theory and how you’re linking them via working through the null hypothesis. I looked on the FRB Wiki. Mm-hmm. And there were about 50 possibilities originally. Some of them have been wiped out. As you mentioned, it’s a beautiful way of doing science, so, Just before we look at your recent move over to the University of Sydney and your research there, can we stay on your MeerKAT and MeerTRAP? … And you mentioned ThunderKAT, that research on the localization of FRBS in

… in February. I saw that you’ve just published a paper about FRB 20210405i.
Can you tell us what you and your team found?

Laura:  This was really exciting for me because I spent a lot of my PhD looking at one particular field that MeerKAT was observing.

So the ThunderKAT team … which is … are you ready for this acronym?
“The Hunt for Dynamic and Explosive Radio Transients with MeerKAT”. So they’ve, they’ve definitely done a bit of cheating there to make ThunderKAT work …

Brendan: Heh heh

Laura: … but they committed at the start of their five years of observing to observing this single X-ray binary called GX 339-4.

They committed to observing that every week for 10 minutes. So what I did was take those images. So, uh, Dr. Lilia Tremou is the one who’s working on GX 339-4 itself … But I took those images and looked at all the other sources in the field to see how they were changing, because this is a … an amazing set of data every week for 10 minutes!

So we really get to see how things are changing in that one patch of sky. And then excitingly MeerTRAP ,.. that’s the other team that I’m in … that’s the Commensal Search for FRBs, RRATs, Pulsars … anything that milliseconds flashes and it’s gone. Started piggybacking and also observing at the same time that ThunderKAT was observing.

So now, as well as having those images every week, we’re getting those MeerTRAP searches for things that flash at the same time. And we happened in 2021 on the 5th of April to detect a fast radio burst … in that very field that I’d spent my entire PhD working on and looking at and staring at with those 10 minute observations every week.

So this was really exciting for me personally. ‘Cause I went, “Yes! That field that I …my favorite field … it’s the one that has the FRB in it!!“
So because ThunderKAT was observing it, we get these nice images and we can make images as short as eight seconds. So even though the FRB only lasts a few milliseconds, this FRB was so bright that even in the eight second image we could see it.

So this is the first FRB localized using MeerKAT because we happen to be working together. These two collaborations, were working really well together. We have a great relationship with ThunderKAT, um, and MeerTRAP. So because we worked together, we saw this FRB and we could actually see where it was. But interestingly, this FRB, it’s dispersion measure, which is a measure of the, the density of electrons between us and the FRB … So it’s a measure of the environment between the observer and the FRB, rather than a measure of a property of the FRB itself.

Brendan: Yep.

Laura:  … That dispersion measure either puts the FRB just on the edge of our galaxy or just outside our galaxy, depending which model you use. But we think, and we are leaning towards, this is another one of those, which theory will win situations, but we’re leaning towards the FRB being coincident with a galaxy that happens to be just outside of our galaxy.

So it’s quite a nearby one. And all of the evidence sort of comes together to support that. So rather than having one smoking gun per se, to say that it’s outside of the galaxy, it’s more of a circumstantial evidence situation where we’ve got all these little pieces that just add up to say that it’s probably at that galaxy.

So that just adds another one to our list of FRBs that have a known host Galaxy, which looks like to us a spiral galaxy. It’s a bit hard to say because there’s a lot of stuff in between us and the galaxy that’s kind of blocking our view. So it looks like it might be a spiral galaxy and that our FRB is sort of a little bit on the outskirts of that galaxy, which is interesting because we don’t typically see Magnetars on the outskirts of galaxies.

Could be something interesting to see there if it is in fact linked up with that galaxy. But it’s just so exciting to finally have that first localization with MeerKAT since we’ve been working so hard on FRBs since the start of my PhD.

Brendan: Fantastic! Well, it certainly is a wonderful area of research and bringing us new knowledge and new understandings, and as you mentioned … new questions.

Okay, let’s look now at your move back over to the East Coast again. How did that all come about and what’s your role at the University of Sydney and what sort of research projects are you working on right now?

Laura:  Yes, the move across we can attribute to Dr. Manisha Caleb, who I also think is one of, was on your podcast probably back in 2018 at the similar time to when I was on the podcast as well.

So Manisha and I were in MeerTRAP and we sat back to back in the office in Manchester and are good friends as well as collaborators and colleagues. And this role came up and I, I thought, you know, Only just finished my PhD. I was only about a year out from finishing my PhD. And that job that Professor Tara Murphy put out looks great, but I’m probably too junior and I know there are some early research career scientists that are probably listening to this, and especially women.

We typically don’t put ourselves forward for things unless we really think we tick all the boxes. So I did fall into that trap, even though I’m aware of that. I fell into it anyway. Lost a little bit of confidence. Didn’t think that I would be right for the role cuz I was pretty junior. But Manisha said, “No, Laura really” … she’s at Sydney as well.

She said, “No, really you should apply for this cause I think you’re a good candidate and just go for it. Why not give it a shot?” Yeah. So having that extra encouragement pushed me over the edge and I went, “Fine, I’ll do it”. It was also a little bit hard because I have to say, I absolutely loved working with CSIRO … and loved Perth.

Brendan: Yep.

Laura: So this is a step up in my career, which is why I ended up taking it. But it was definitely not because I didn’t love living in Perth or working with the team at CSIRO. I still have ties with them and I’ll probably join up as an affiliate for the CSIRO as well. Cause I really did enjoy my time over there.

Brendan: Yep.

Laura: So I … I really applied because Manisha said: “Go for it!” And now I’m a postdoctoral researcher. So Professor Tara Murphy recently took up the role of Head of School of Physics at the University of Sydney. So she has to work out how to balance her role as a Science Lead and a Team Lead as well as the Head of Physics.

So my role as a postdoc is to keep doing my research and doing lots of fun, exciting things with VAST and ASKAP, but also to help her keep on track with her students and make. Team meetings still run and that there’s someone there, but for anyone to sort of touch base with and keep things going on track for her Science as well.

So it’s a really great leadership role for me to take on as well. So I’m really excited about the science as well as taking that extra step as an early career researcher to take that leadership role on as well. So I’m excited to be over here, to be closer to my family who are all in Melbourne, but also to really take that next step in my career.

Brendan: Fantastic! And from our point of view at Astro is you were certainly ticking all the boxes …  Laura, last time we spoke, you mentioned that you’ve made Outreach one of your priorities, and I love hearing the excitement in your voice when you’re talking about your research. What about research and you want to bring to the public a wider understanding of Science and how scientists work? You’ve explained that beautifully just before when you were talking about the Null Hypothesis. Are you still involved in Outreach projects?

Laura: I am, I’m really excited. You mentioned at the very start that I was selected as a Superstar of STEM for this year and next year. So for those of you who don’t know, the Superstars of STEM is a program, a two-year program run by Science and Technology Australia, and it’s where 60 women and gender non-binary people around Australia are chosen every two years to be part of this program.

The main purpose is to build the profile of women in science in the media in particular. So at the moment, basically if you see a scientist come onto The Project or on ABC radio, they’re typically a man. So the purpose of the superstars of STEM is to get women into those media spots instead, just so that we can really show people, and of course young women and girls and young boys and men as well, that you don’t have to just be a man to be a scientist.

Cuz sometimes that’s sort of what it feels like. And of course that’s not to say that I don’t have loads of wonderful male colleagues out there … there are lots of excellent science communicators of all types out there. But it is key that we do show that you can be anyone and be a scientist. And I think when I go into schools, which is another aspect of the Superstars of STEM is to …  is to go into schools on Zoom or in person and just show the work that we do so that that really opens the minds of kids. But I … I find that it’s so important to really show that we’re people as well, and I think most people don’t think about it this way, but if you go to your local shopping center, you’re probably walking past someone with a PhD every time you go to your local shopping center. And you wouldn’t know because just like in all careers, whether you’re an accountant or a hairdresser or a plumber, Most people just look like everybody else, and we all have all of our other things that we do.

For example I sew my own clothes and I also love to go for a, a nice walk along the Rose Bay foreshore near Sydney. So I think that’s one of the key things that I … I really like to do it when I do science communication is show that we are just like everybody. But I also have to say that I absolutely love doing anything, like having a chat with you, Brendan, or going into schools or going to an outreach event.

It really invigorates my enthusiasm for what I do, cuz I do love what I do. But when you speak to people who are truly wowed, cuz we forget, we’re in our own little bubble. Everyone that I work with is the leading expert in the world on what they do.

Brendan: Yep.

Laura: And so you end up in this bubble where we’re all doing something really amazing … So it’s only when we get to really share that, that I go, “Yes! You’re right! This is truly amazing that I get to do this every day!”
So it really reinvigorates me as well as hopefully spreading the word of, of how great science is and just the options. So if one kid sees me and then realizes that there are more options open for them, whether it’s astronomy or something else, then my job is done.

Brendan:  Exactly! … and putting that diversity front and center is really important. It’s important to us here at Astrophiz. We’ve got a diversity policy and we try and make sure that we represent the community as much as possible. Our guests are really diverse and it’s very exciting for me here as well. I can hear the excitement in your voice.

Right now might be a good time to ask how the current worldwide Covid 19 crisis has impacted on your work. You alluded to it earlier and we always hope that it’s over, but it keeps on keeping on. I’m still wearing a mask when I go into crowded indoor situations. I hope your diplomat, twin sister, and your folks down in Melbourne are still all okay?

What are your personal and professional reflections on the Covid 19 pandemic … Uh, Laura?

 Laura: Oof. I think like a lot of people, I probably have a lot of thoughts on this. I’m with you as well. On public transport and in crowded indoor spaces, I’m still sticking my N 95 on. It’s a small change I can make to even just avoid having the common cold.

I think during Covid, we all realized how annoying that was when you have a cold too. So even just those … those … little things. Trying to miss the usual bugs is, is something that I’m very happily on board with. I think it’s really interesting to me, and as I moved into different states in Australia, to reflect on how the Covid situation impacted all of us individually in a very different way, and I think that’s something that we have to be really.

Aware of an understanding of when we interact with people. Because I was in the UK when the pandemic started, I’d actually just got back a couple of weeks earlier from a trip to Cape Town in South Africa, and that was when they were still doing the temperature testing. But we all hadn’t, definitely hadn’t sunk in how serious the situation was.

So we then went into lockdown in the UK and about three months after we went into lockdown, I sort of had this epiphany that I didn’t need to be staying on my own in an apartment in the UK and I could go home. So I did spend the rest of the pandemic in Melbourne living with my parents, and I’m very lucky.

I’m one of the people who gets on very well with my parents, so I was happy to be there. Our family dogs close to the Yarra Valley region where you could go for a lovely walk, and it was a little bit of a different situation. For me, but it was the last 18 months of my PhD working from the other side of the country to my supervisor and all my colleagues.

We were all, you know, sitting in our homes or apartments on our own. But it was a bit different being in a totally different time zone without having that, a ability to say, “Hey, can you help me with this?” … So I was lucky that it was the end of my PhD because I’d already sort of established my research abilities and I was able to independently push myself to keep working.

And I can thank my parents and my family as well for their support in that. But then even moving to Perth was like going to a whole another world because they’d barely been touched by the pandemic compared to Melbourne where we had a five kilometer radius and a curfew. So every time I’ve moved it, I’m an alien in a different land trying to work out how the world has been.

I think in Perth it was most interesting because people didn’t stop over there, whereas a lot of us over on the East coast, you know, all of our hobbies sort of fizzled out. We couldn’t go and play tennis on the weekend or … I don’t know …go to Roller Derby or whatever your chosen sport is. So our lives stopped and we kind of took a step back and reevaluated the things that we really wanted to spend our time on.

Whereas in Perth, people were going, “Oh, I’ve got this on tonight and I’ve got that on tomorrow”. And I sort of went, “Wait … What? …What? You don’t, you don’t have hobbies? We don’t do that.” So it was, it was very, it was very, very strange to go to a place where they hadn’t … where … where we’d been so impacted in Melbourne to go somewhere where they’d barely been touched.

So, It was tricky. So my twin sister is actually the, the orthopedic surgeon. It’s my older sister who’s the diplomat. She was in the US at the start of the pandemic, so that was tricky, and even coming home for her was a bit harder than the UK. Luckily, my sister, who’s a surgeon, I think she’s only had Covid once somehow, so she’s been very careful about masking and things like that, despite being in a hospital environment every day.

But it was tough … just the … for her … the not knowing of whether, you know, the next day she was gonna be called into a Covid ward or something like that, or into emergency rather than fixing people’s broken hips and things like that. So it’s definitely … everyone’s experience has been different, and I think that’s the main thing.

As far as professionally, it’s mainly affected conferences and how we come together as scientists. I think some people have been more flexible and aware of how the impacts of that and how some of the things we should keep going from an accessibility perspective, people being able to join, whether they have kids or caring responsibilities, people who have disabilities who might find travel challenging.

Um, I think being able to do hybrid and actually trying, rather than just going, “Oh, we’ll stick it up on Zoom” … but helping to truly make those online experiences valuable and useful for network. So I… I really appreciate the people who are working in that space and, and actually trying to make these things better and adapting rather than just going, “Oh, we’ll just go back to the old ways now”.

Which was better for a lot of people to go in person, but for some people it wasn’t. So, I don’t think it hurts us to … to really think about how we’re gonna move forward rather than just defaulting back to the old ways.

Brendan:   Exactly, and we’ve got more choices now. So there have been some good things that have come out of it.

For me, the big thing for me is my admiration  … or adoration of medical professionals. It’s limitless. My … I cannot thank our medical professionals enough the way they’ve carried us through this pandemic. Please pass thanks on to your surgeon sister. Thanks from all our audience as well. Let’s now bring our listeners up to date with the nitty gritty of your current work.

Could you talk us through some details of a particular problem that you’re working on now that’s driving you crazy or astonishingly exciting, or perhaps both Laura?

 Laura: I think a lot of what we do is a bit of both of those things. Often the problems that … that come out the most … are the ones that are … that are annoying us.

So we spend a lot of time trying to fix the problem cuz it’s just killing us. So I … I mentioned a bit that I’m working on radio stars now. So what that means is, at the moment I’m trying to find stars that emit radio waves. So this is important because as I mentioned earlier, we haven’t really done too much work.

There have been a few people who have done some excellent work in the interim, but really the major effort on radio stars was in the eighties or nineties, and then a couple of people managed to keep it going in between, and now we’ve brought it back. Other people like Joe Callingham … Dr. Joe Callingham, who’s in the Netherlands at the moment, has also been a … a big part of that working with LOFAR.

But one of the key problems is that if you look up at the night, Hopefully everyone has at least a halfway decent view of the night sky where they are. You can see a whole lot of dots, and we know that almost every single one of those dots is a star. If we took a picture of the same patch of sky with our radio telescope, we also see a lot of dots, but we know that almost all of those dots are in fact … radio galaxies … not stars in our own galaxy.

Brendan:  Yep.

Laura: I think a lot of what we do is a bit of both of those things. Often the problems that … that So that means if I find a star, an optical star at a certain spot on the sky and there happens to also be a radio spot at that same position, chances are very high that that’s just a galaxy hiding behind a star. It’s difficult, I should say, to prove that the radio light is truly coming from the star rather than an AGN an Active Galactic Nucleus, hiding behind the star.
So that’s one of the things that’s driving me crazy, but that also leads to some creativity in how to prove that the radio light is truly coming from the star. So one of the ways I did this, that is a paper that will be out soon, I just resubmitted my response to the referee two days ago.

So that should be out soon, fingers crossed.

Brendan:   Yep.

Laura: My trick Is to use proper motion. So when we look at those stars, we can’t see it, but most of them are moving. So if you imagine someone running past you and you take a photo, wait a few seconds and take another photo. In those two photos, the person will be in two different spots.

Brendan:   Yep.

Laura: But the trees and houses behind them will be in the same spot because they don’t move. And it’s similar. Our stars that are close by in our galaxy are like the person running, they move across the sky, but other galaxies in the far distance. The houses and trees in the background, whether we wait 30 years or a hundred years, they should stay in the same spot on the sky while the stars are moving.

So what I did is I took some radio images that were taken about 30 years ago with the first survey, which is a bit of an annoying name because it makes it hard to say. The first survey was the first radio survey that I used. So thanks for that naming convention. So that’s a very large array survey. And the more recent ASKAP Sky surveys … and the Rapid ASKAP Continuum Survey and the VLA Sky Survey. The VSS.

Brendan: Yep.

Laura: And I was looking for things that have moved from 30 years ago. Are they in a different spot now? And I found a few stars that way. So that’s a way to prove that the radio light that we see is coming from the start itself. And there are a few different.

So that’s the thing that’s driving me crazy and is also exciting cause it’s a fun problem to try and work around. I think that leads to lots of creativity for all of us looking for stars.

Brendan: Ah, that’s beautiful Science, Laura, and your explanation has a clarity to it. That’s sparkling. Thank you. Is there anything else that we should watch out for in the future? I’ll certainly catch your paper when it comes out.

What are you keeping your eye on?

Laura: I think one of the most exciting things and, and something that a few of us in the Radio Star space are working on is trying to see whether we can find exoplanets by using radio observations. So for those of you who are across JWST and KEPPLER and all that sort of thing, we have lots of  good ways to find other planets. So an exoplanet is a planet that’s orbiting a star that’s not our sun. So all those stars out there …  loads of them have planets and we have to find ways to see them. So there are lots of optical missions. Um, TESS, the Transiting Exoplanet Survey Satellite … I always mix up what the S’S stand for … It’s something like that. That was the … the successor to KEPPLER is finding planets all the time. But we’re trying to see if we can see any of those hints that there’s a planet there in the radio. So that’s something to keep an eye out for that a few of us are working on. No one’s done it definitively yet, but we’re trying, and it could be really fun.

Brendan: It is fun! … and I just saw last week … JWST had looked at, I think it was the Innermost Trappist exoplanet, and they said, “No, you could not live on it. It’s not Earth. 2.0”.

Laura: Yes! Unfortunately that’s probably gonna happen a lot. I think that we are very … we don’t realize how lucky we are that earth even existed in the first place because there’s not many other places where we could have evolved the way that we did.

Brendan: Exactly … Okay … Look, our time’s just about up Laura … So thank you so much, Dr. Laura Dreissen. On behalf of all of our listeners and especially from me, I’m learning so much by osmosis here. It’s been really fantastic to be speaking with you again, and thank you especially for your time. I know the pressure that exist in departments in universities. I really understand how difficult it must be to squeeze in all the demands that you have on your time.

Now, the listeners, Laura’s website is AstrolauraDOTcom. On social media, you’ll find Laura, she’s @astrolauraD on Twitter and her non-astro artistic and construction things are on Etsy at Oomigoomi …  and you mentioned your dog earlier …
Her whippet dog is on Instagram at  AstroDOTtheDOTwhippy. Do you want to talk about Whippy?

Laura: I … well … I can just say that he’s … he’s a whippet. He’s with my parents because he’s got anxiety. So like many of us, he struggles a little bit with mental health, so he stays there with my parents. But Astro is a reference to Astro Boy, the old school Cartoon TV show.

Brendan: Yep.

Laura: And also Astro from the Jetson. So astronomy, but also more of an old school cartoon dog.

Brendan: Okay. A big shout out to Astro the Whippy on Insta. Okay. Good luck with all your projects, Laura, and with your next adventures. We’ll have to have you back on the show again in another few years. Thank you so much, Laura.

Laura: It’s my absolute pleasure, Brendan. I always love having a chat with you and I think we could put in our calendars 2028, we can have another chat.

Brendan: Thanks Laura. Have a great day.

Laura: You too. Thanks Brendan. See you later.

Brendan: And remember listeners … Astrophiz is free and unsponsored … But we always recommend that you check out Dr. Ian Musgrave’s Astroblogger and Southern Skywatch websites to find out what’s up in the night sky each month.

Keep looking up!