This summer was fantastic.
I had the incredible opportunity to live in New York City while interning at the American Museum of Natural History (AMNH), researching planet formation. The best part was meeting all of the cool and interesting people in New York, especially at International House, where I stayed for the summer. It was a truly global community, filled with people from every continent and all walks of life: students, professionals, artists, scientists, musicians, people of every belief (and none); people from South Sudan, Indonesia, China, South Africa, India, Europe, and across the Americas. Our late-night conversations, shared meals, and cultural exchanges were the most inspiring part of my time in Ney York. I also got to meet with Neil deGrasse Tyson - his office is near the lunch table in the Astrnonomy area.
My research mentor at AMNH was Dr. Linn Eriksson (see her work here), and we focused on understanding how planets like Uranus and Neptune form. These two ice giants are actually hard to explain in our current models of planet formation. Most planets in our simulations either stay Earth-sized or leap straight to Jupiter-size through runaway gas accretion. Forming something in-between, like Uranus and Neptune, requires specific disk conditions.
Our approach combined several stages of modeling. We started with simulating how dust and gas evolve in a young solar system’s disk, and used that to find where gravitational collapse could form planetesimals. Then, we modeled the growth of successfully formed planetesimals via pebble and gas accretion. We originally didn’t think Uranus and Neptune would be able to form. Once we found out that they could form, I added type-I migration to the model, in which the planet interacts with the gas disk, creating waves. The waves between the planet and the star are usually weaker than the waves on the outside, so the planet will often spiral inwards towards the star.
I also got to practice my Linux and Unix skills, because I decided to run the parameter study (a study varying the parameters that are put into the model based on observational uncertainty) on my server back home in Utah. I was able to log on to my computer at home in Utah all the way from New York City, and with that I set it to run the thousands of runs in an 8-dimensional parameter space without needing to stop the simulations for any reason. We found several realistic scenarios where Uranus and Neptune analogs could form and migrate without becoming gas giants. We hope to expand this into a publishable paper.
With the end of summer comes the dawning of the new school year. Over the next month, I will be diving back into my coursework and resuming my research at BYU. My main BYU project focuses on exoplanet interiors, specifically the Kepler multiplanet systems, and trying to understand what these distant worlds are made of. I have also worked on galaxy morphology using data from the TNG50-SKIRT Atlas.
Another amazing part of my time at BYU is being able to work in the planetarium. It’s a powerful tool for teaching and for science communication, and I hope to make the most of it this semester, both for sharing astronomy and for refining my science communication and teaching skills. I have a full plate in the coming months between research, planetarium work, and grad school application prep, but I am excited for all of it. I am most excited that my wife is almost back from her summer adventures and will be here soon to share the rest of the year with me.
Thanks for reading,
Raymond Kelly