2025 Sagan Summer Workshop Hands-On Sessions

Overview

We encourage all attendees to participate in these hands-on sessions, select one of the group projects to work on during the week, and make informal group presentations at the end of the workshop. Our goal is to allow both in-person and remote attendees to participate; however, support for remote attendees may be somewhat limited.

Colab Notebooks

The hands-on session activities will use Google Colaboratory (Colab) Notebooks. As the Colab Notebooks run in your Google Drive using a virtual machine, and do not require a Python installation, they are the easiest way to work on the hands-on sessions. No prior Python experience is required to participate in the hands-on sessions, but a free Google account is required to run the Colab Notebooks, and we request that you run the Setup Notebooks prior to the Workshop. For experienced Python users, the Colab Notebooks can generally be downloaded and run as Jupyter Notebooks, but there may be dependencies that need to be installed in addition to the defined packages.

Hands-On Session I: Exoplanet Occurrence Rates

Ilaria Pascucci (Arizona/LPL), Galen Bergsten (Arizona/LPL), and Gijs Mulders (Pontificia Universidad Católica de Chile)

The distribution of exoplanet occurrence rates (the intrinsic rarity of a certain type of planet) informs our understanding of how planets form and evolve. Yet any exoplanet survey is limited in what it can and cannot observe, so bias characterization and correction are essential steps in occurrence rate calculations. New techniques allow us to combine data from multiple surveys, each with distinct biases, to explore occurrence rates over a larger and more diverse sample, leading to a more holistic understanding of exoplanet demographics.

In this hands-on session, we will use bardic to learn the basic techniques behind occurrence rate calculations and modeling with data from one or more surveys, including:

• How to visualize survey data from transits, radial velocity, and direct imaging.
• How survey biases affect measurements of planet frequency.
• How to model the occurrence distribution from a single survey.
• How to combine data from multiple surveys when modeling occurrence rates.
• How assumptions in the modeling process can impact measured occurrence rates.

Hands-On Session II: Distant Giant Planets with Astrometry

Brendan Bowler (UCSB) and Tim Brandt (STScI)

Over the next few years, Gaia is expected to deliver an abundance of giant planets from 1-7 AU that can eventually be used to study the demographics of cold Jupiters with unprecedented numbers. Getting to this point will require understanding how to use astrometry in conjunction with other techniques to validate and characterize planets. This activity explores the synergy between absolute astrometry, imaging, and radial velocities to access a new discovery space for giant exoplanets.

You will:

• Use astrometry to detect stellar accelerations across the sky.
• Use these accelerations to predict the possible nature of the companion responsible for the tug.
• Predict the detectability of the companion in direct imaging.
• Propose observations to discover and characterize the companion.
• Learn the power and limitations of absolute astrometry, and how to combine it with knowledge of a system’s age to determine the space of exoplanets that is open to discovery.

(last updated April 7th, 2025 14:08:38)