It’s not every day that researchers discover a new planet, but that’s exactly what happened to researchers at the Centre for Astronomy. Using the latest iterations of the world’s largest telescopes, they were able to study a dust disk, allowing them to eventually discover the planet lurking within. Through collaboration with other universities, the hard work of many student researchers … and maybe a sprinkling of magic dust? … a new planet was found, to the amazement of the scientific community, the media, and even the then President of Ireland.
To discuss this groundbreaking discovery, the Content Unit sat down with University of Galway’s Dr Christian Ginski and PhD student Chloe Lawlor to uncover how their cutting-edge space research is rewriting what we know about the formation of planets.
Bríd Seoige (BS): Chloe and Christian, thank you so much for joining us this morning. Chloe, could you just please introduce yourself, and tell us if you were always interested in this field of work?
Chloe Lawlor (CL): I’m currently a second-year PhD student, and my research journey actually began with binary stars – systems made up of two stars orbiting around each other. I started out modelling their orbits and their interactions, but since the discovery of WISPIT 2b, my focus has shifted toward dust studies. Now, I’m researching the properties of dust in systems where we know planets already exist. When you know there’s a planet there already, you can study the types of dust present to infer which types are more efficient at forming planets in similar environments. It’s really exciting!
Interestingly, I didn’t always plan to study physics. It wasn’t really until my Leaving Cert that I started considering physics as a career; but I didn’t even do physics in the University originally. I actually began studying art and design because I wanted to work in animation, but I realised it wasn’t quite the right fit. So, I decided to switch to physics and see how that goes. And sure, here I am!
BS: Christian, can you introduce yourself, please? What did you study in university? Were you always interested in this field?
Christian Ginski (CG): I’m Christian Ginski, and I’m a lecturer in the School for Natural Sciences, within the Physics Unit, specifically in the Centre for Astronomy here at University of Galway.
I joined University of Galway in early 2023, so I’m still relatively new here. Before that, I did postdocs in the Netherlands at the University of Amsterdam and Leiden University.
When I completed my university degree, there was no difference between Bachelor’s and Master’s programmes; it was essentially an integrated Master’s in Physics, or the equivalent. I completed that degree and my PhD in the Friedrich Schiller University in Jena, Germany, which is around halfway between Berlin and Munich.
I have been interested in astrophysics for as long as I can remember. Even in high school, before I began my physics studies, there was this book that had a huge influence on me Black Holes and Time Warps by Kip Thorne, the Nobel Prize-winning cosmologist and theoretical physicist at Caltech. This book explores black holes, time warps, and the history of physics and cosmology leading up to our understanding of these phenomena. This sparked my interest in and passion for astrophysics to the point that I realised this was the direction I wanted to go in.
Funnily enough, my current research is quite different from what first inspired me in astrophysics. I very much come from the observational side of astrophysics, using large telescopes to collect data and interpret what it tells us about the universe.
Throughout my career, I’ve been working on high-contrast and high-resolution imaging, which means that I try to see faint things that appear very small on the sky due to their large distances to us. My goal has always been to discover new planets or to study the environment where planets form. These two areas have been a constant in my research.
BS: That brings me nicely on to discovery of this new planet, WISPIT 2b. Maybe I will firstly ask Chloe; can you talk us through your part within this discovery as a PhD student?
CL: It kind of led on from what I was doing in my undergraduate final year project, where I modelled the orbits of binary stars. For the discovery of the planet WISPIT 2b, I applied similar methods, this time modelling the orbit of the planet around its host star. A few months earlier, Dr Ginski had published a paper in which I calculated whether a planet of a particular size could create a gap of a specific size within a system. The work I did for WISPIT 2b built on that, showing that this planet could theoretically open such a wide gap, and is likely the primary cause of it.
It was really exciting at the time but hard to keep it a secret! It didn’t quite feel real until the paper was published and all the media attention started. Suddenly, we were doing interviews, I was seeing myself on the news, and people I knew and people I didn’t were coming up to congratulate me. They’d say things like, ‘Oh, I saw you on TV!’ It was a bit surreal, and I’d end up saying something like, ‘Oh, that’s nice!’
BS: Christian, can you talk us through the process and discovery of WISPIT 2b?
CG: To me, this was a really fun discovery, because it was completely unexpected. The project initially discovered the surrounding dust disk, before detecting the planet itself. It’s part of a study called WIde Separation Planets In Time, or WISPIT.
WISPIT was the same name that was given to the star system and the planet. The study itself is led by colleagues at Leiden Observatory. It uses quite literally the Very Large Telescope (VLT), which has an 8-metre main or primary mirror size, to study planetary systems around young nearby stars. This is one of the largest near-infrared and optical telescopes currently available on Earth.
We figured out that by pointing this telescope at a young star for just a few minutes, we could detect whether a very wide separation planet was orbiting it. That’s how the study got its name: WIde Separation Planets In Time. The ‘in time’ part comes from our aim of observing stars of different ages, to find out whether planets can form very far from their stars, at distances of hundreds of astronomical units, meaning hundreds of times the distance between the Earth and the Sun.
This wasn’t something that theory had originally predicted. Only a few planets have been found at such large separations, and we wanted to understand where they originate from, whether they form out there or form much closer to their star and are later scattered outward through dynamical interaction or similar processes. That’s why we wanted to observe both very young stars and older stars for comparison, to see whether planets appear in one population or the other.
Richelle van Capelleveen, a PhD student at Leiden Observatory who is leading the study, contacted me to say that she had somewhat unexpectedly found a dust disk around one of the stars we were observing. This was significant. She had only a few minutes of integration time, so the image wasn’t especially striking, as the short exposure time and lack of optimisation meant it was hard to get a detailed disk image.
Since most of the stars we were studying were old enough that their disks should have already dispersed – they typically disperse after a few million years – it was quite unexpected to find a star that still had an extended disk.
From there, things started to spiral and take off. I realised that this was a very extended disk and would be a very good target to check whether a planet might currently be forming within it. I convinced Richelle to give up a little bit of her observation time; she traded observation time planned for four or five stars, and instead caried out a long observation sequence on this disk. At this stage, we didn’t have the planet yet, but we now had an image of this beautiful dust disk.
As luck would have it, I still had some telescope time left, and I thought, this is the perfect chance to see if there’s a planet lurking in one of those gaps in the disk.
So I submitted a request to use some of my remaining telescope time to observe it. Then, one beautiful Saturday morning, while I was having breakfast, I decided to check the observation logs, something I probably shouldn’t be doing on a Saturday morning, admittedly. That’s when I saw it: the observation was in! It only takes a few minutes to run the data processing on my laptop, so I started it up while I was eating. And there it was, the planet, sitting right in the gap, exactly where we expected it to be!
You know, I’ve been searching for an object like this for nearly 10 years, something as clear and as compelling as what we found here. Nothing even close had materialised in my research before. So, to suddenly see that little dot of light, sitting right exactly where the physics predicted it should be, was absolutely exhilarating.
I was, quite literally, over the moon.
BS: Was it the collaboration with other universities and parts of the world that made that happen?
CG: Very much so. Without the work done in Leiden, we would have never looked at this particular star. It is in a somewhat obscure region of the sky. It was definitely not on anyone’s bucket list of a must-observe system.
It was only through Richelle’s diligent work that we learned that there was a dust disk there. Through our discussions and shared telescope time, we were then able to identify the planet. We also collaborated with a partner in Arizona, who carried out complementary observations. They observed the planet in a different way, looking at wavelength of light that signifies different physical effects occurring in and around the planet.
That partnership came about thanks to a University of Leiden faculty member who had previously worked in Arizona. Through his contacts and this international collaboration, we were able to gather so much data on this planet in a very short time. You know, observational cycles operate on a yearly basis, but our timeline was very short.
From the moment that Richelle first showed me the disk image in November or December, to the follow-up observation in March, and finally the planet’s discovery in April, everything happened really fast!
BS: The story of WISPIT 2b’s discovery has been covered by the media as groundbreaking research. How old do you think the planet is; can you estimate? Can you talk us through the impact of this discovery?
CG: I think WISPIT 2b is about 5 million years old. That’s the number what we ended up with. It might sound incredibly old to anyone who isn’t used to operating in astronomical timescales, but 5 million years is basically the toddler stage for a star. For comparison, the Sun is around 4.5 billion years old, so a few million years makes WISPIT a very young system.
When I said I was hunting for a case like this for about 10 years, it’s not just me. Many astronomers have been observing these beautiful dust disks around young stars, but we’ve only been able to capture such detailed images for roughly the past decade. This is thanks to advances in telescope and detector technology. It’s a fairly new field of research, and it gives us an opportunity to study structures in dust disks, spiral arms, and rings.
There are so many beautiful images – which people think are AI generated – but the fact is they’re not. How exciting is that!
The entire field has been trying to prove what we’ve long suspected: that when we see spiral arms in a disk or gaps in a disk, it’s because a planet is in effect shaping the dust, or when we see a gap, that the planet is sort of vacuuming up material, clearing a gap as it’s growing. It’s a nice theory, but for a long time we had very little observational evidence to back it up.
Until we found this particular planet, there was only one other system where the entire community agreed that we had detected the planets. This system was called PDS 70. It’s very famous in our field, discovered in 2018, and contains two planets inside a large cavity in a dust disk with a single ring. Since that discovery, we’ve been trying to find more systems like that, because one case does not prove a general trend.
We can’t say: ‘We found this planet in one singular system; that means all of the structures that we are seeing in dust disks are caused by planets.’ That would be far too big a leap. We are trying to find more examples of those planets, which has proven very difficult for various reasons. Dust can partially obscure the planets, making their thermal emission and infrared light difficult to detect.
We have to apply a lot of image processing to remove the light from the central star, which is many orders of magnitude brighter than the disk or planets we might hope to see.
These complex disk structures can also lead to false positive detections that might look like planets but are artifacts from image processing. This is a common problem.
That’s why discovering this planet was so exciting! It really was one of the clearest cases of a planet that forms in a disk, and because the dust disk has multiple rings and gaps, we believe it is quite likely that there is even a multi-planet system forming here. We are witnessing planet formation in action.
Since the paper there has been a hive of activity, sparking a flood of observation requests across major telescopes. The entire field is very excited and for good reason.
BS: You mentioned observation time. Can you explain what that is, and tell us if you’ve scheduled time since appearing on RTÉ?
CL: Yeah, so there are only so many hours in the year, and only so many hours in a night, yet everyone wants to observe the skies. It used to be twice a year for the Very Large Telescope (VLT), but now it’s once a year. You submit a proposal justifying your case and why you want to observe. There are probably hundreds of applications, so not everyone will get the time they request but they must take into account what is most feasible and likely to have the greatest scientific return.
CG: Telescope time is heavily oversubscribed. It’s extremely competitive. Chloe and I are putting significant effort into writing observation proposals to secure more time.
We are searching for more planets in other systems based on this discovery. In fact, we have selected a number of systems that we think are also likely to contain planets.
Chloe has put together a really innovative proposal looking at multiple-ring systems using the James Webb Space Telescope. If she’s awarded the time, we think it could lead to genuinely breakthrough results. We’re looking forward to it.
BS: Christian, you came to the University in 2023. What attracted you to University of Galway?
CG: The honest answer is that opportunities in astronomy and astrophysics are incredibly competitive. There are many brilliant people in the field, and only a limited number of permanent positions. After completing my PhD, I spent about 10 years in postdoctoral roles and eventually began applying for permanent positions. University of Galway was recruiting to replace a researcher whose work was in a similar area to mine. There was a clear interest in strengthening research in planet formation, young stars, and related topics, which made it a natural fit for my expertise. One standout factor made Galway unique: my colleague Dr Nicholas Devaney’s involvement in the development of instrumentation for the Extremely Large Telescope (ELT), the next iteration of large telescopes. It will be the absolute biggest optical near-infrared telescope in the world! He is involved in building an instrument for this telescope, which means that University of Galway already has guaranteed time on the ELT when it comes online. That was a major attraction and a rare opportunity in my field. To put it in context, the current telescopes have an 8-metre main mirror size, where the ELT will have a 40-metre main mirror size.
To elaborate: the clean room where this instrument is being built is in mainland Europe. Dr Devaney is leading much of the optical design work from Galway and travels over when needed – so it’s not being assembled in a lab on campus. The project is part of the European Southern Observatory, the same organisation that runs the Very Large Telescope.
So while the role itself initially drew me in, it quickly became clear that Galway’s faculty and projects made it the ideal place for me to be in Ireland.
BS: I’ve seen the pictures of that beautiful mural donated to the University as a result of this fantastic discovery. Maybe I’ll start with you, Chloe; is there anything else that you would like to add?
CL: I thought it was really amazing to be invited up to Áras an Uachtaráin to meet the then President of Ireland, Michael D. Higgins. It’s not something you ever expect to happen because of your research. I mean, we think our research is very groundbreaking, but it doesn’t directly affect people’s everyday lives, it’s not as pressing as presenting cures for cancer. It was a wonderful and memorable experience to meet him.
CG: Yes, the appreciation shown by the former President and the Irish national media uptake was amazing. I think the genuine interest was not only in the research itself but because young researchers were at the heart of it. The first planet ever identified was discovered by a PhD researcher. But here, for WISPIT 2b, perhaps uniquely, the entire research team was basically made up of students. That helped make this discovery bigger and a lovely feel-good story.
For me, it’s the most rewarding research I’ve ever been part of, not just scientifically, but because we wrote the paper together as a group of five, all in one lecture hall. It was genuinely fun, and the students’ contributions were central to that.
As for the former President of Ireland’s event, as Chloe said, Michael D. Higgins is such a lovely man, and we’re grateful to him for showing such appreciation. I’m not sure I’ve fully processed that the mural was gifted as an appreciation of our work. It’s an incredible honour.
Our work tries to answer something deeply human: how planets form, how life begins, and ultimately, where we come from. We can’t look back in time, but by studying young stars and planets around other systems, we get glimpses of how our own story started. We’re looking up, but in many ways, we’re also looking back at ourselves.
Profiles
Chloe Lawlor is a PhD Physics student at University of Galway, completing a specialisation in astrophysics. She contributed to the discovery of the planet WISPIT 2b and co-authored a groundbreaking paper alongside Dr Christian Ginski and fellow University of Galway students Jake Byrne, Dan McLachlan, and Matthew Murphy.
Photo Credit: Martina Regan
