Prerequisites

Before starting this tutorial, ensure that:

  • GUIBRUSHR is installed and properly configured, including the petitRADTRANS opacity databases. Refer to the installation instructions and in Appendix B of the reference paper.

  • The WASP-77Ab tutorial datasets are downloaded and placed in the appropriate target folder. The datasets can be obtained from [link to tutorial data].

  • Opacity line lists for the molecular species of interest are available at both high and low resolution in the petitRADTRANS input data directory (see below).

Provided opacity line lists

The tutorial data package includes the opacity line lists for the three molecular species used throughout this analysis:

  • H2O: the POKAZATEL line list from Polyansky et al. (2018), which provides a comprehensive and accurate set of water vapor transitions suitable for high-temperature exoplanetary atmospheres.

  • CO: the HITEMP line list with natural isotopic abundances from Rothman et al. (2010), widely adopted for carbon monoxide at the temperatures relevant for hot Jupiters.

  • CO2: the HITEMP line list from Rothman et al. (2010). In the original analysis by August et al. (2023) and Smith et al. (2024), the UCL-4000K ExoMol line list (Yurchenko et al. 2020) was used for CO2. However, the UCL-4000K opacity tables exceed 20 GB in size, making them impractical to distribute with the tutorial package. We therefore provide the HITEMP CO2 line list as a lighter alternative. For higher accuracy, particularly when targeting CO2 features in detail, users are encouraged to download either the UCL-4000 (Yurchenko et al. 2020) or the more recent CO2 Dozen line list (Yurchenko et al. 2025).