Welcome
I’m an astrophysicist looking to transition my career path from academia into data science, particularly either in public service or in tech. I know that isn’t typical, but an astronomy career track prepares one well for roles in data science, project management, and public outreach among others. Below you can find my career interests as well as a brief description of past projects. A bit further down are interests outside of work.
In the past, I’ve worked on several projects: at UC Santa Cruz I worked with Jonathan Fortney on modeling brown dwarf and hot Jupiter atmospheres. We are interested in the thermal evolution of these astrophysical objects in addition to their compositions in order to characterize them. As my first year project at Leiden I worked with Yamila Miguel modeling the interiors of hot Jupiters with MESA and simulating oscillatory modes with GYRE to investigate what might excite hot Jupiter oscillations. My master’s thesis was with Matt searching for co-moving companions around Sun-like stars in the nearest OB-associating Scorpius-Centaurus (Sco-Cen).
My career interests
I am addicted to the news and how the news get made. Notably, the LA and NY Times circulations are among my favorite sources of information concerning issues across the board, from war to science, foreign and domestic. Given my background, I principally aim to serve as a “data journalist,” where I tell a story through meticulously crafted data visualizations that are easy to follow yet thorough.
I am an avid supporter of Green New Deal policies and have applied across the United States to positions in industry and in government concerning the implementation of policies that would wane us off of fossil fuels. Climate change is the largest existential threat to humanity today; action is needed now!
I am a member of the LA Works volunteer force. Community involvment is principle in forging a better world for our future and so I am a big fan of not-for-profit institutions whose goals include attacking society’s most dire issues (vaccines, hunger, housing, and more).
Finding co-moving companions around Sun-like stars
One major area of exoplanet detection and characterization involves gathering a large sample size of planets orbiting stars like our own. Taking HCI VLT/SPHERE data originally from Bohn, A. et al. I queried the ESO archives for additional epochs for 11 of 72 stars in their YSES survey. We computed accurate and precise astrometry to analyze companion candidate proper motions in order to determine the nature of these objects in the primary target field-of-view. I confirmed the primary target 2MASSJ12560830-6926539 (roughly 130 pc) is a trinary star system, with the primary target consisting of two stars: one close-in (hereafter 2M1256Ab) at 29 au separation and a farther object (2M1256B) orbiting 100 pc away (500 au separation) respectively. Using orbital models obtained with orbitize!, we calculated a median orbital period of 292 years assuming a circular orbit and 342 years not assuming a circular orbit. We’d like to better constrain the shape of the orbit, but for that we’ll need more data! We also constrained the mass of 2M1256B to 82 / 49 Jupiter masses using photometric data from 2MASS and GAIA and fitting the results to a 3 Myr BT Settl isochrone using the model effective temperature and luminosity respectively (Teff / L).
Exploring the possibility of oscillations in extrasolar giant planets (EGPs)
Stars and planets oscillate. Asteroseismology, the theoretical and observational study of oscillations, reveals to us the internal structure of stars. The nature and causes of these oscillations is mostly a mystery in the case of EGPs; however, we must learn more about them in order to better understand the internal structures of these sub-stellar bodies. In our Sun as an example, helioseismological measurments revealed a ridid-rotating core and a differentially rotating envelope. Here, “rigidly rotating” refers to the entire core rotating as a single object with a single angular/rotational velocity around the stellar center. For differential rotation, one can think of Jupiter. The bands on the surface of Jupiter don’t move together; in fact, they rotate with pretty different velocities. In my work with Yamila, we showed that the semi-major axis (roughly the average distance from the planet to the star) is the most important parameter when asking the question, “what causes a planet to oscillate?”
Modeling brown dwarf atmospheres
Atmospheres drive the evolution of planets. The Earth, with a thinner atmosphere, would look vastly different from the one we know. In simplest terms, though, we’d expect the Earth to be colder and much more arid, similar to Mars. With a thicker atmosphere, we’d look a tad more like Venus. This is true for gas giant planets and brown dwarfs, which are are sub-stellar objects that aren’t hot enough fuse hydrogen to helium like normal stars. Brown dwarfs are a good analog for Jupiter-sized planets, so we study them to get an idea of how giant gas planets might behave. With Jonathan Fortney, I ran over 10,000 model brown dwarf and exoplanet atmosphere models. We explored many parameters, including chemical composition, radius, and mass, surface gravity, temperature, and clouds in order to see how their spectra (a chemical fingerprint for an object) look. We inform our models with new observational data as well, ensuring up-to-date theoretical spectra.
Other stuff I enjoy
I’m a big music guy stretching from OG Rap like Biggie and Pun to Midwest Emo a la American Football. I love going to DJ shows, concerts, blues clubs, everything. I love sports too and have played rugby for 4 years. I’m a proud Banana Slug and LSRG affiliate. Go USA Eagles!
A big thank-you to academic pages template makers and all others who’ve made this website easier to make!
This is the front page of a website that is powered by the academicpages template and hosted on GitHub pages. GitHub pages is a free service in which websites are built and hosted from code and data stored in a GitHub repository, automatically updating when a new commit is made to the respository. This template was forked from the Minimal Mistakes Jekyll Theme created by Michael Rose, and then extended to support the kinds of content that academics have: publications, talks, teaching, a portfolio, blog posts, and a dynamically-generated CV. You can fork this repository right now, modify the configuration and markdown files, add your own PDFs and other content, and have your own site for free, with no ads! An older version of this template powers my own personal website at stuartgeiger.com, which uses this Github repository.