A Kiel Diagram Featuring the Lithium Dip for GALAH-GAIA Survey Data (Ages Move from Left to Right)
Credits: Smedile, 2025
My research interests primarily currently reside within theoretical astrophysics, primarily in Steller Theory. I work with Dr. Marc Pinnsoneault on utilizing Astroseismological and spectroscopic data to develop theoretical models for the hot side of the lithium dip. The lithium dip is an apparent decrease and increase in lithium abundance in stars when plotted against color, age, temperature, etc. which appears between ~6000-7000K I work to provide models for different case scenarios such as meridional circulation due to rotation, convection, chemical gradients induced by gravity, and more.
I also analyze how lithium may be preserved or created in post-Main Sequence Stars (PMS), specifically Red Giant Branch and Red Clump stars. Intuition would suggest that the dredge-ups and structural changes that occur inside a star leaving the Main Sequence (MS) would deplete most/all lithium. However, large-scale surveys such as GALAH and LAMOST have shown a sizable population of these stars with relatively high abundances of lithium. The discontinuity with stellar models is likely due to binary interactions in these stars, as well as a lack of mechanisms to inhibit mixing such as internal magnetic fields or slow rotation in these models.
Lithium is an important tracer of numerous processes in stars. Because it fully ionizes at relatively lower temperatures, it is a good age indicator of stars. Furthermore, the presence/absence of lithium can also indicate different modes of circulation, spindown rate, and convection in stars. Doing so can improve stellar models for mixing, and help to refine the ages for stars. This also can provide better estimates for Galactic Chemical Evolution, and Big Bang Nucleosynthesis by adjusting the parameters in these models to account for different modes of lithium creation/preservation/destruction. Refining these models will help us better understand how galaxies and their chemical makeup evolve and how the elemental abundances we see today were generated from the Big Bang.
The Yale Rotating Stellar Evolution Code (YREC) is a stellar evolution model that builds upon the theoretical work of Kippenhahn and Thomas in 1970 and the Heyney in 1959 code to provide models of rotating stars. The code solves the equations of rotation as a 1.5D problem, building on the work from Kippenhahn and Thomas 1970 and Endal and Sofia 1976. It also incorporates convective overshoot and RIM models from Zahn 1991. I work alongside the author, Prof. Marc Pinsonneault, and other current and former students of Prof. Pinsonneault to make this code publicly available.
My role is the development of wrappers and other user-interfaces in modern languages such as Python to better assist in the usage of the code.
Theoretical predictions from a YREC Z=0.01689 Subgiant Model showing Convective Envelope Mass vs A(Li)
Credit: (Smedile & Pinsonneault, in prep)
As a student of both science and politics, I have a strong passion for science policy. Oftentimes, scientists and politicians find it hard to communicate despite relying on one another for a myriad of reasons. Scientists need funding that only Congress can provide, likewise the right scientific development or project can bring funds to a district or provide a strategic edge against a rival power. Despite this, we scientists and politicians rarely in the communicate the same way. Moreover, science's inability to properly communicate it's value in an appealing way to politicians often means they get funding cut or seen as a luxury in the grand budget schemes of the Hill. As a student of both, I hope to bridge that gap and brings these communities closer by helping to advocate more funding to the sciences in a way that strengthens the American Republic and people.
To that ends, I currently work with Dr. B. Scott Gaudi, a member of the Habitable Worlds Observatory (HabEx) START team in advocating the next Great Observatory to our nation's government.
I also periodically serve as Executive Secretary for NASA during grant proposals, which allows me to help determine funding for missions that best advance these goals.
As an ever ardent advocate for those wirthout a voice, I always work to advance the student experience wherever I am. I serve as the At Large Representative on the Advisory Board to the Dean of the OSU College of Arts and Sciences. In my capacity, I meet with the ASC Dean once a month to communicate pressing issues facing graduate students. If you ever have anything you wish to convey, please feel free to contact me! See my contact page for details :)
As an undergraduate, I worked on soft X-ray instrumentation to design sounding rocket payloads capable of combining wide fields of view and resolutions capable of resolving spectral lines such as OVII and OVIII. I was primarily involved with the assembly of components, the testing of systems, and the creation of spectral source models and instrument models. I was also involved in the Pulsar Search Collaboratory at Penn State, which used drift scan data from Arecibo to calculate the scintillation bandwidths of over 300 pulsars and use them to map the ISM.