Welcome

Hello! My name is Ryan Rubenzahl (he/him). I am a postdoctoral researcher at the Flatiron Institute's Center for Computational Astrophysics where I work with large datasets of the Sun taken by Extremely Precise Radial Velocity (EPRV) spectrometers (like KPF and NEID) to study stellar variabliity and instrumental systematics at the individual pixel level. I recieved my PhD from Caltech in 2024 where I built the Solar Calibrator (SoCal) for KPF and explored the origins of close-in giant planets such as WASP-107 b, KELT-18 b, and Kepler-1656 b by measuring their stellar obliquities. More broadly, I use the radial velocity (RV) technique to understand the demographics of exoplanets across our galaxy and advance the technique to be sensitive to Earth-Sun analogs. I am a member of the Terra Hunting Experiment (THE) which will soon be starting a decade long survey with the new HARPS-3 spectrograph to search for Earth-like exoplanets around the nearest Sun-like stars.

I am currently rebuilding my website (because I upgraded Hugo and it broke everything) -- stay tuned as I transfer and update to this new site.

Me, pointing at my PhD thesis instrument, the Solar Calibrator (SoCal).

Research Highlights

  • KPF Project Manager Kodi Rider assembling the main spectrograph at the Berkeley Space Sciences Laboratory.

    KPF

    I'm a part of the the Keck Planet Finder instrument and science team: check out our commissioning progress!

  • The Solar Calibrator (SoCal).

    SoCal

    I built the Solar Calibrator to study stellar activity on the Sun with KPF.

  • The angle between a planet's orbital plane and its host stars rotation axis is called the obliquity.

    Obliquities

    I use RV spectrographs to measure the (mis)alignment between an exoplanet's orbit and its host star.

Outreach

  • Showing a local Pasadena family the November 11, 2019 Mercury transit through my telescope + solar filter

    I regularly participate in our astronomy outreach program at Caltech, including stargazing events on campus, on sidewalks in downtown Pasadena, and in National Parks like Death Valley.

  • I gave a public lecture for CaltechAstro outreach on our YouTube channel about how radial velocity spectrographs work and why stellar activity is such a big problem.

Community Organizing

  • CGPU logo

    I'm a founding member of Caltech Grads and Postdocs United, the active effort at Caltech to form a labor union for graduate and postdoctoral researchers. Please reach out if you have unionization questions and/or are interested in forming a higher-ed labor union at your institution!

  • Pasadena Measure H

    I believe we can all do our best work when economic barriers to living and working in the US are removed. That's why I and other Caltech grad students helped collect over 15,000 signatures to win the strongest rent control and just-cause eviction protections in the country, right here in Pasadena CA.