obafgkm 🌟

An interactive Python tool for plotting representative stellar spectra across different spectral types and metallicities! Perfect for astronomy education, research, and stellar classification studies.

📖 Table of Contents

• Features
• Installation
• Quick Start
• Usage
• Parameters
• Examples
• Data Sources
• Project Structure
• Contributing
• Citation
• License
• Acknowledgments

✨ Features

• Interactive Stellar Spectra Plotting: Generate and visualize synthetic stellar spectra with customizable parameters
• Wide Parameter Range:
  • Effective temperatures: 3000K - 8000K
  • Surface gravities: log(g) = 0.0 - 5.0 dex
  • Metallicities: subsolar ([M/H]=-2.0), solar ([M/H]=0.0), and supersolar ([M/H]=0.5)
• Dual Spectra Display: View both normalized and unnormalized flux spectra
• Spectral Line Markers: Automatic labeling of important spectral features (Ca H/K, H-alpha, H-beta, Na D lines)
• Export Capabilities: Save high-resolution plots for publications and presentations
• Pre-computed Spectra: Fast loading from pre-synthesized MARCS/Korg models

🚀 Installation

From PyPI (Stable Release)

pip install obafgkm

From GitHub (Development Version)

# Latest development version
pip install git+https://github.com/rocketxturtle/obafgkm

# Or clone and install locally
git clone https://github.com/rocketxturtle/obafgkm.git
cd obafgkm
pip install -e .

Dependencies

The package requires the following Python libraries:

• numpy - Numerical computations
• pandas - Data manipulation
• astropy - Astronomical utilities
• matplotlib - Plotting functionality

These will be automatically installed with the package.

🎯 Quick Start

# In the terminal
python
import obafgkm.prompt as p
p.run()

This will launch an interactive session where you can select stellar parameters and generate spectra.

📊 Usage

Interactive Mode

The simplest way to use obafgkm is through the terminal:

python
import obafgkm.prompt as p
p.run()

After which ou'll be prompted to select:

1. Effective temperature (3000, 4000, 5000, 6000, 7000, or 8000 K)
2. Surface gravity (log(g): 0.0, 1.0, 2.0, 3.0, 4.0, or 5.0 dex)
3. Metallicity ('subsolar', 'solar', or 'supersolar')

Programmatic Usage

For more control, you can use the package by manually setting the Star object parameters:

import obafgkm.main as obafgkm
from obafgkm.plot import plotter

# Create a star object with specific parameters
star = obafgkm.Star(
    effective_temperature=5000,  # K
    surface_gravity=4.0,         # log(g) in dex
    metallicity='solar'          # or 'subsolar', 'supersolar'
)

# Generate spectra data
spectra_data = star.select_spectra()

# Plot the spectra (with optional save)
plotter(spectra_data, save=True)  # Set save=False to just display

Custom Plotting

Access the raw spectral data for more detailed analysis:

import obafgkm.main as obafgkm
import matplotlib.pyplot as plt

star = obafgkm.Star(5000, 4.0, 'solar')
unnorm, norm, params, filename = star.select_spectra()

# unnorm and norm are numpy arrays with wavelength and flux columns
wavelength = norm[:, 0]  # Wavelength in Angstroms
flux = norm[:, 1]        # Normalized flux

# Create your own custom plot
plt.figure(figsize=(12, 6))
plt.plot(wavelength, flux)
plt.xlabel('Wavelength (Å)')
plt.ylabel('Normalized Flux')
plt.title(f'Teff={params[0]}K, log(g)={params[1]}, [M/H]={params[2]}')
plt.show()

🔢 Parameters

Effective Temperature (Teff)

• Available values: 3000, 4000, 5000, 6000, 7000, 8000 K
• Covers spectral types from M to A stars

Surface Gravity (log g)

• Available values: 0.0, 1.0, 2.0, 3.0, 4.0, 5.0 dex
• From supergiants (low log g) to main sequence/subdwarfs (high log g)

Metallicity ([M/H])

• subsolar: [M/H] = -2.0 (metal-poor)
• solar: [M/H] = 0.0 (solar abundance)
• supersolar: [M/H] = 0.5 (metal-rich)

🌟 Examples

Example 1: Solar-like Star

import obafgkm.main as obafgkm
from obafgkm.plot import plotter

# Create a Sun-like star (G-type)

sun_like = obafgkm.Star(
    effective_temperature=6000,
    surface_gravity=4.0,
    metallicity='solar'
)
plotter(sun_like.select_spectra(), save=True)

Example 2: Red Giant

import obafgkm.main as obafgkm
from obafgkm.plot import plotter

# K-type giant star

red_giant = obafgkm.Star(
    effective_temperature=4000,
    surface_gravity=1.0,
    metallicity='solar'
)
plotter(red_giant.select_spectra())

Example 3: Metal poor Dwarf

import obafgkm.main as obafgkm
from obafgkm.plot import plotter

# Metal-poor dwarf star

subdwarf = obafgkm.Star(
    effective_temperature=5000,
    surface_gravity=5.0,
    metallicity='subsolar'
)
plotter(subdwarf.select_spectra())

📁 Project Structure

obafgkm/
├── __init__.py              # Package initialization and version info
├── main.py                  # Core Star class and spectra selection
├── plot.py                  # Plotting utilities and visualization
├── prompt.py                # Interactive user interface
├── rcparams.txt            # Matplotlib configuration settings
├── star_types.csv          # Database of available stellar spectra
├── normalized_spectra/     # Pre-computed normalized flux spectra
├── unnormalized_spectra/   # Pre-computed unnormalized flux spectra
└── plots/                  # Saved plot outputs (created on first save)

📈 Data Sources

The spectral data in this package were synthesized from:

• Model Atmospheres: MARCS model atmospheres
• Spectral Synthesis: Korg spectral synthesis code
• Wavelength Range: Full optical coverage
• Resolution: High-resolution synthetic spectra

Note: Current temperature range is limited to 3000-8000 K. Future releases aim to expand this range to include O and B type stars (>8000 K) and cooler M dwarfs (<3000 K).

🤝 Contributing

We welcome contributions! Please feel free to:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes (git commit -m 'Add some AmazingFeature')
4. Push to the branch (git push origin feature/AmazingFeature)
5. Open a Pull Request

Areas for Contribution

• Extending temperature range beyond 3000-8000 K
• Adding more metallicity options
• Implementing additional spectral analysis tools
• Improving documentation and examples
• Adding unit tests

📚 Citation

If you use obafgkm in your research, please cite (bibtex):

@misc{obafgkm,
  author = {{Gozman, Katya}, {Sinha, Amaya}, {Schochet, Meir}, {Ramon, Lisha}},
  title = {obafgkm: Interactive Stellar Spectra Plotting Tool},
  year = {2025},
  publisher = {Zenodo},
  doi = {10.5281/zenodo.16762220},
  url = {https://github.com/rocketxturtle/obafgkm}
}

📜 License

This project is licensed under the MIT License - see the LICENSE file for details.

🙏 Acknowledgments

• Created at Code/Astro workshop
• Spectral synthesis using MARCS model atmospheres
• Synthetic spectra generated with Korg
• Special thanks to the astronomy community for feedback and testing

🐛 Bug Reports & Questions

Found a bug or have a question? Please open an issue on our GitHub Issues page.

🔮 Future Enhancements

• Extend temperature range to include O/B stars (>8000 K)
• Add ultra-cool dwarfs (<3000 K)
• Implement spectral classification algorithms
• Add interactive Jupyter widget interface
• Include additional spectral line identification tools
• Support for custom wavelength ranges
• Integration with observational data formats

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Happy stellar spectroscopy! 🔭✨

Remember: The universe is under no obligation to make sense to you, but these spectra might help!