Yale’s new 51 Pegasi b fellow will explore origins of ‘hot’ Jupiters

Quang Tran, a new recipient of the prestigious 51 Pegasi b fellowship who will join Yale this fall as a postdoctoral fellow, has begun a promising line of research on the formation of “hot” Jupiters — gas giant planets that are physically similar to Jupiter, with high surface atmosphere temperatures.

Tran’s journey is compelling as well.

His mother lived in a Malaysian refugee camp for seven years in the aftermath of the Vietnam War before emigrating to the United States. Tran was three years old when he arrived in the United States, and he credits his mother’s devotion and tenacity for making it possible for him to investigate astronomical mysteries today.

“It’s important to me to appreciate the choice and freedom I have to be a scientist exploring questions about the universe — and how far I’ve come, thanks to my mom,” said Tran, who will receive his Ph.D. in astronomy this spring from the University of Texas at Austin, before starting his new fellowship at Yale in the fall.

The 51 Pegasi b fellowship, which is named for the first exoplanet (a planet outside our solar system) discovered orbiting a sun-like star, provides up to $430,000 in support for independent research over three years. The Heising-Simons Foundation established the fellowships in 2017 to provide postdoctoral students with the opportunity to conduct theoretical, observational, and experimental research in planetary astronomy.

At Yale, Tran will focus on younger “hot” Jupiters. More specifically, he is interested in the evolution of these planets — and how and why they are positioned so close to their host star.

The relatively young age of the “hot” Jupiters that Tran is exploring is what makes them challenging to find, he said. The brightness of a young host sun creates “noise” that obscures the detection signals coming from nearby planets.

Tran’s idea is to use an instrument called the Habitable-Zone Planet Finder — an astronomical spectrograph based at the McDonald Observatory in western Texas — to lower the amount of stellar noise. With this approach, Tran hopes to clarify details about the formation and development of “hot” Jupiters. He also plans to combine existing surveys of young stars to locate enough giant exoplanets of similar age to make comparisons with older planets of similar size and proximity to their host stars.

“Today we have some advanced techniques and statistical frameworks for modeling exoplanets — but people are getting different results,” Tran said. “We need more observations and new methods to robustly characterize these systems and understand what might be missing from existing theories and models.”