Exploring the Universe One Continent at a Time

By Maksym Mohorian
[email protected]

The La Silla Observing School 2024, organised by ESO, has been a journey unlike any other – at least for me, a Ukrainian in Australia. From the breathtaking landscapes of the La Silla Observatory (Figs. 1 and 2 below) to the science-intensive lectures and workshops, every moment has left me in awe of this School. The selection to the school was on a merit-based competitive basis, where at the end only 20 out of 140 international applicants were selected. Just 2 out of the 20 students selected were from Australia, including myself, and I was the only participant from Macquarie University. Most of us were PhD students with just a couple of Master students and an early-career postdoc.

We were split into four groups and were assigned small projects to experience the full observing cycle from planning to analysis. The group I joined explored the spectroscopy of two hot Jupiters: WASP-121b and WASP-122b. To do this, we obtained high resolution spectra of the planet-hosting stars in-transit and out-of-transit using the HARPS+NIRPS spectrographs installed on the 3.6m telescope. We learned how to prepare the ESO observations (Phase 2), how to perform them in person, how to reduce the data using EsoRex and EsoReflex, and how to analyse the transmission spectra of exoplanets.

Maksym at La Silla
Figure 1: Maksym Mohorian at La Silla Observatory, with the 3.6m telescope at the summit and New Technology Telescope (NTT) to the left.
Figure 2: The 3 telescopes of the robotic BlackGEM array, whose goal is to detect and characterise optical counterparts to gravitational wave detections.

I was particularly excited about the control room experience. The quiet background music coming from an ancient computer in the corner, the similarly ancient fridge fully stacked with yoghurts and soft drinks, the diversity of unique sounds for any possible notification of every telescope, and the periodic anxious check-ups of the all-sky camera – there were many things which made the in-person observing so great. And with the La Silla facilities, we were able to experience the front end of current astronomical research.

Overall, the lectures on instrumentation and science at ESO, workshops on Python in astronomy, and scientific projects were highly informative and useful. And now, preparing for postdoc and fellowship positions, I am grateful for the opportunity I got to explore the state-of-the-art astronomical facilities and to meet the ESO community (Fig. 3 below) – which is another thing that truly makes ESO stand out. Whether it was a research meeting with the tutor or a short chat at the coffee break, there always was a sense of hospitality and benevolence that transcends borders and languages.

Astronomers at La Silla
Figure 3: Exoplanet project group of the 2024 La Silla Observing School, the 3.6m telescope, and the Galactic bulge. Left to right: Richard Cannon, Mariam Haidar, Amanda Ormazábal, Maksym Mohorian. Image credit: Richard Cannon.


Michael Murphy is the Australian representative on the ESO Science Technical Committee. Contact: [email protected]

Sarah Sweet is the Australian representative on the ESO Users Committee. Contact: [email protected]

Stuart Ryder is a Program Manager with AAL. Contact: [email protected]

Guest posts are also welcome – please submit these to [email protected]