Ultra-cool dwarf (a.k.a. brown dwarf) catalogs for Celestia

Celestia forum thread: https://celestiaproject.space/forum/viewtopic.php?f=23&t=23911

This project consists of Python scripts for generating catalog files from the UltracoolSheet (UCS) for Celestia, a 3D space simulator.

Pre-built files are provided in the Releases subpage.

Features

• Support for single ultra-cool dwarfs and binary/multiple systems
• Collects designations from several catalogs (including variable-star and GJ identifiers)
• Missing parameters filled by interpolation of the BHAC15 and COND03 isochrones
• Handles objects already in Celestia's default catalogs (via the Exclusions table)
• Allows for overriding/updating some parameters in the UCS (via the Supplemental_data and Binaries_supplemental_data tables)

Setup

The scripts require Python 3.7 or higher to run.

1. Clone this repository or download it from GitHub.

2. Download the following files from the Zenodo UCS repository, and save them to this repository's data directory:

   • UltracoolSheet - Main.csv
   • UltracoolSheet - Binaries.csv
   • UltracoolSheet - Triples+.csv
   • UltracoolSheet - FundamentalProperties.csv

3. Create a virtual environment (make sure the terminal is in this project's directory):

   python3 -m venv .venv

4. Activate the virtual environment:

   # Linux/macOS
   source .venv/bin/activate
   
   # Windows
   .venv\Scripts\activate

5. Install the required dependencies:

   pip install -r requirements.txt

Usage

python celultracool.py [-v] [-c] [-m] [-n]

The following arguments are supported:

• -v, --verbose: Enable verbose output during generation.
• -c, --catalogs: Include additional catalog designations (Pan-STARRS1, 2MASS, MKO, WISE).
• -m, --multiples: Include companions, and binary/multiple systems.
• -n, --nearby: Include objects within 10 parsecs but not in Celestia's nearstars.stc catalog (which is limited to 25 ly).

Output

These generated .stc files are saved in the output directory:

• ultracool.stc: Main catalog of ultra-cool dwarfs.
• ultracool_bins.stc: Catalog of binary and multiple systems (if --multiples is enabled)

Acknowledgements

This work has benefitted from The UltracoolSheet at http://bit.ly/UltracoolSheet, maintained by Will Best, Trent Dupuy, Michael Liu, Aniket Sanghi, Rob Siverd, and Zhoujian Zhang, and developed from compilations by Dupuy & Liu (2012), Dupuy & Kraus (2013), Deacon et al. (2014), Liu et al. (2016), Best et al. (2018), Best et al. (2021), Sanghi et al. (2023), and Schneider et al. (2023).

This work has made use of the SIMBAD database, operated at CDS, Strasbourg, France (Wenger et al. 2000).

References

Evolutionary model grids

• Baraffe et al. (2003), A&A 402, p. 701-712. "Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458" (link to data)
• Baraffe et al. (2015), A&A 577, A42. "New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit" (link to data)

Empirical relations

• Filippazzo et al. (2015), ApJ 810, 158. "Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime"
• Kirkpatrick et al. (2021), ApJS 253, 7. "The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs"
• Luhman et al. (2003), ApJ 593, p. 1093-1115. "A Census of the Young Cluster IC 348"
• Pecaut and Mamajek (2013), ApJS 208, 9. "Intrinsic Colors, Temperatures, and Bolometric Corrections of Pre-main-sequence Stars" (link to data)
• Sanghi et al. (2023), ApJ 959, 63. "The Hawaii Infrared Parallax Program. VI. The Fundamental Properties of 1000+ Ultracool Dwarfs and Planetary-mass Objects Using Optical to Mid-infrared Spectral Energy Distributions and Comparison to BT-Settl and ATMO 2020 Model Atmospheres"
• Zhang et al. (2018), MNRAS 479, p. 1383-1391. "Primeval very low-mass stars and brown dwarfs - III. The halo transitional brown dwarfs"

Values in the Supplemental_data and Binaries_supplemental_data tables come from a multitude of sources, cited by their bibcodes. Fields without a cited source have been extracted from the UCS main table.