Take 10 with... Heloise Stevance

Dr Heloise Stevance from the Department of Physics gives us 10 minutes of her time to discuss stellar deaths and cosmic fireworks.

Dr Heloise Stevance, Department of Physics
Dr Heloise Stevance, Department of Physics

1.  Describe your research topic to us in 10 words or fewer.

I use computers to understand how stars go bang!

2.  Now explain it in everyday terms!

Understanding the Universe is difficult because we are stuck on Earth and we cannot recreate the extreme conditions of space in a lab. All we can do is look at the sky, take images of the light that comes from stars and their explosions, or try to detect gravitational waves - they create ripples in the fabric of space time. Then, we compare these observations to computer simulations made by theoretical astrophysicists: if you can explain previous observations, and predict future ones, you know your model/simulation is pretty accurate. My job is to be the middle-woman between theorists (my boss) and observers (my colleagues), so we can understand how stars explode, merge, and create the building blocks of life.

3.  Describe some of your day-to-day research activities.

I write a lot of computer code, specifically in Python, for other people in my community and myself. I am currently developing new methods with machine learning - it’s challenging and really fun. When I’m not coding I’m reading, and when I’m not reading I'm writing papers to tell my colleagues what I found!

4.  What do you enjoy most about your research?

I love the topic. Stellar deaths and cosmic fireworks are my jam. Better understanding the things that explode in the night sky is my passion. As for everyday tasks, I love it when I manage to automate a complicated job with a good piece (or pieces) of code. It is so satisfying.

5.  Tell us something that has surprised you in the course of your research.

I literally just learnt that neutron stars have been confirmed to have quarks in their center. Let me explain: neutron stars are the very dense, very dead remnants of massive stars that have exploded – they are the densest objects in the Universe after black holes. They are so dense that normal atoms cannot exist in their inner layers: protons and electrons are squished together to make neutrons. As it turns out, even neutrons melt away in the extreme conditions of their center and all that’s left is an incoherent soup of their fundamental building blocks: quarks.

6.  How have you approached any challenges you’ve faced in your research?

One challenge we recently encountered was a difference in the age of stars we find with our model and previous age determination methods. This is very important to get right so we can properly understand massive stars, supernovae, neutron star mergers, etc.

To check that discrepancy we used state-of-the-art data, compiled from the Very Large Telescope and Hubble Space Telescope, and compared it with our most up-to-date simulations.

7.  What questions have emerged as a result?

The research above exposed some issues with previous methods to find the age of star clusters – so we asked ourselves: can we come up with a systematic, universal way to do this? And we are in the process of developing this method right now.

8.  What kind of impact do you hope your research will have?

Stellar explosions are not just important, they are essential to creating the building blocks of life: carbon, oxygen, iron, etc.

As Carl Sagan said: we are made of star stuff. My job is to better understand where that stuff comes from; where we come from.

9.  If you collaborate across the faculty or University, who do you work with and how does it benefit your research?

I work with people across the globe, including the US, UK, Israel, Germany, and Australia. I cannot name all my collaborators but I am so grateful for them.

10.  What one piece of advice would you give your younger, less experienced research self?

It’s important to remember that science IS challenging. We are pushing the boundaries of human knowledge, so it’s easy sometimes to feel like an idiot and like you know nothing: that’s called imposter syndrome. It’s very important to remind yourself that you are not dumb, science is just hard, and you’ll get there eventually. Good science takes time!