A Python Package for Multidimensional Atmospheric Retrievals of Exoplanet Spectra
POSEIDON is a spectral modelling and atmospheric retrieval code for exoplanets. Given a set of observed exoplanet spectra from space-based or ground-based telescopes, POSEIDON uses Bayesian techniques to infer the atmospheric properties of the planet.
POSEIDON's supports the modelling and retrieval of exoplanet transmission, emission, and reflection spectra, alongside emission spectra of brown dwarfs.
NEW: POSEIDON now supports high-resolution cross-correlation retrievals for ground-based high-dispersion instruments.
The installation guide and a wide-range of tutorials for different applications can be found in the POSEIDON documentation.
If you use POSEIDON in your work, please cite MacDonald & Madhusudhan (2017) and MacDonald (2023).
A more specific guide of recommended citations for specfic functionality in POSEIDON is provided in the documentation page: What to Cite.
Copyright 2023-2026 Ryan J. MacDonald
POSEIDON is available under the BSD 3-Clause License. Please see the LICENSE file for more information.
For bug reports or feature requests, please raise an issue.
Interesting in contributing to POSEIDON? Please see the contribution guide.
Feel free to reach out to Ryan MacDonald (Ryan.MacDonald@st-andrews.ac.uk) or Elijah Mullens (eem85@cornell.edu).