Welcome to the petitRADTRANS documentation. petitRADTRANS is a Python package for calculating transmission and emission spectra of exoplanets, at low ($$\lambda/\Delta\lambda=1000$$) and high ($$\lambda/\Delta\lambda=10^6$$) resolution, for clear and cloudy atmospheres.

Important

Scattering is currently not included for emission spectra in petitRADTRANS (but it is for the transmission spectra). We intend to migrate the scattering implementation of petitCODE to petitRADTRANS soon.

petitRADTRANS is available under the MIT License, and documented in Mollière et al. (2019). Please cite this paper if you make use of petitRADTRANS in your work.

This documentation webpage currently contains an installation guide, a tutorial, a first code documentation, and an implemented retrieval example for mock JWST emission and transmission spectra. Also, we give a tutorial on how to calculate opacities that may be missing from our database.

## News¶

27 May 2019: high-temperature atom and ion opacities now available
We have added the opacities of Fe, Fe+, Mg, Mg+, Li, Ca, Ca+, Si, Si+, O, O+, Al, Al+, Ti, Ti+, V and V+, up to temperatures of 4000 K. As usual, if the atmospheric temperatures increase above 4000 K, petitRADTRANS will use the absorbers respective opacities at 4000 K. Please make sure to install the latest petitRADTRANS version to make use of the high-temperature points of the new opacity tables!

Code documentation: