The young astronomer unlocking the secrets of how planets form
Yuki Okoda has always been fascinated by the great mysteries of the universe. Inspired by her high school physics teacher’s stories on the theory of relativity, elementary particle experiments and exoplanets, Okoda pursued a career in astronomy. She could never have anticipated what would happen next.
In September 2018, as a second-year Master’s student at the University of Tokyo, the young astronomer became the first person to discover a dense disk of material around a newborn star. The discovery, which could shed light on the origins of our solar system, became world news.
For many, this attention could have proved daunting, but the 23-year-old took it in her stride. “I had never imagined my research would be in the global news spotlight,” she reflects three years on. “At first, I felt it wasn’t real, but was honoured that people outside of science were interested in the discovery.”
The following year proved to be a whirlwind. Okoda was named in the BBC’s 100 most influential women in the world and joined fellow up-and-coming Japanese scientist, Yukiko Ogawa, in the prestigious 2019 Asia Forbes 30 Under 30.
“Both had a huge impact, introducing my research to people all over the world,” says Okoda, now 26, who is studying a PhD at the University of Tokyo. “I hope that our (physics department’s) work can stimulate people’s intellectual curiosity and continue Japan’s rich tradition of pioneering astronomy.”
Okoda’s research continues to enhance our knowledge of how solar systems form. Using radio-wave observational data and images from the Atacama Large Millimeter/submillimeter Array (ALMA), the largest radio telescope in the world, she analyses newborn stars. Okoda is part of a small team of six researchers in the university’s physics department.
“I study the environment around very low mass protostars,” says Okoda, who explains a protostar is a very young star that is still gathering mass from its parent molecular cloud. “I observe molecular emissions around these stars and look to solve when and how disk structures, which may be a precursor of a planetary system, form.
Okoda continues to investigate the source where she found a rotating disk structure in 2018. Her discovery back then involved hours of painstaking analysis trying to make sense of grainy images. However, the model Okoda came up with fit the data perfectly, describing a dense disk of material that consisted of gas and dust from the cloud that surrounded the star. This had never been seen before around such a young star.
“It has been thought that a disk structure is formed around an evolved protostar aged from 10,000 to 100,000 years, but what I found was that the disk had already formed around a protostar as young as 1,000 years old,” she says. “This implied the co-evolution of the planetary system and the protostar. I only have one example that the disk structure forms at such a young age, so I need to study other very young stars.”
The Kure-born astronomer, living in Tokyo with her younger brother who is a law student at the university, believes it’s an exciting time to be working in astronomy. “The recent development of observational technology can provide us with analysis we could never have previously imagined,” says Okoda.
Observational astronomy and telescope engineering have made rapid progress over the past two decades. This is thanks to tools like the European Southern Observatory’s Very Large Telescope array, ALMA in Chile, and the National Astronomical Observatory of Japan’s ATERUI II, the most powerful supercomputer in the world dedicated exclusively to astronomy.
Japan’s Subaru Telescope in Hawaii, which has been observing the skies since 1999, remains one of the world’s most powerful and technologically advanced reflecting telescopes. It continues to play a key role in unravelling the secrets of the universe, from imaging exoplanets and mapping dark matter, to solving solar mysteries.
For now, the global pandemic has put a pause on Okoda’s protostar observations, but she hopes her story will inspire more young women to pursue astronomy as a potential career in Japan. She recalls her male dominated astronomy classes, yet is cautiously optimistic that attitudes are changing and stereotypes shifting in her native country. “I think early exposure to STEM subjects for girls is really important,” she says. “The percentage of women in astronomy is very low. I hope our success will inspire a new generation of astronomers in Japan to reach for the stars.”
