In Conversation With…William Brilliant, Scholar of the P.C. Ho PhD Studentship at the University of Cambridge

William Brilliant grew up in Greenwich, London, where visits to the Royal Observatory and the planetary shows first sparked his interest in astronomy. A key moment was when his mother gave him several space infographics, posters, storybooks, and DVD sets on astronomy: “One of the DVD documentaries was on the Gas Giants and the Voyager missions. I watched it maybe a dozen times. I was fascinated with the people behind the missions processing the data, so I went from wanting to be an astronaut to wanting to become an astronomer!” While astronomy wasn’t offered at his school, he was a member of the school’s astronomy society where they would meet monthly at Regent’s Park Hub to stargaze.

William pursued his interest by studying physics at the University of Oxford. While his undergraduate degree did not include a core astronomy module, he sought out the subject through optional short modules. Though William explored other subjects, interning in a lasers and atomics lab, astronomy remained his passion. In his final year, he pursued an integrated Master’s in physics: “I studied astrophysics and atmospheres & oceans, knowing I wanted to specialise in exoplanets. We know about eight planets in our solar system, but any planet found around another star is classed as an exoplanet. So far, the research community has discovered around 6,000.” He adds that their significance lies in what they reveal about our own world: “Exoplanets help us understand how planetary systems form and evolve. If we want to know what our system looked like in the past or what it might look like in the future, we need to study others. They also give us clues about how life arose on Earth, and whether the conditions that made it possible here are common elsewhere in the Universe.”

During his Master’s, William joined the Planet Hunters for the Transiting Exoplanet Survey Satellite (TESS), a citizen science project aiming to detect exoplanets on wide orbits that were missed by the main data processing pipeline: “TESS is a satellite that has been operating since 2018 that measures the light emitted from each star, and produces light curves, graphs showing changes in brightness over time. When there are small dips in these light curves, it can indicate that a planet is passing in front of the star, revealing a potential exoplanet.”

After completing his Master’s in 2024, William joined the Cavendish Laboratory as a P.C. Ho Scholar at the University of Cambridge. His PhD research builds on his contributions to The Terra Hunting Experiment, a project that aims to find Earth-mass, Earth-year planets using a brand-new spectrograph called HARPS3: “We are still in the golden age of finding planets but up until recently only those that are massive and close to the stars have been identified. We have a huge population of large, gaseous, hot planets, but a real deficit of small, rocky, temperate or cold planets. Part of my research is to expand the parameters to identify more types of planets, seeing what comes into the scope and how you can extract those features.”

On his experience as a P.C. Ho Scholar, he notes: “It’s incredible to be part of a new mission and working on a new instrument. The aim is to find an ‘Earth twin’ and it’s a privilege to contribute towards something that is potentially the most informative type of exoplanet.” William also enjoyed constructing the mechanical parts of HARPS3 which was brought from Cambridge to La Palma in the Canary Islands where the lower levels of light pollution help with the detection of signals in the sky: “The challenge is to get enough precision in our instrument because if we built it slightly wrong, the optics won’t be perfectly aligned. And with this kind of mission, it would be death by a thousand cuts.”

Looking ahead, William is keen to remain in the world of exoplanets: “there is room to explore within exoplanet research. I could change the type of technique I use to detect planets. For example, at the moment, I am working with the radial velocity technique and at my Master’s I worked with the transit technique, but there’s other methods I could explore.”

William appreciates the role that private philanthropy plays in his academic pursuit: “I could not have gone to Cambridge or pursued a PhD without this funding.  The chance to follow what has been my dream since I was a child is so special and my time as a P.C. Ho Scholar has been very rewarding.”