A Python Package for Stellar Photometry

Stellarphot is a Python package to allow you to turn reduced astronomical images of point sources (e.g. stars) into useful photometry, with a focus on variable star and exoplanet transit observations. Specifically:

• If you have reduced astronomical images as FITS files but haven't obtained photometry yet, stellarphot can perform aperture photometry on your images.
• If you already have aperture photometry for a field, stellarphot can
  • choose comparison stars based on a catalog (e.g. APASS DR9),
  • calculate relative flux (like AstroImageJ),
  • calculate calibrated magnitudes by transforming to a catalog (e.g. APASS DR9), and/or
  • calculate calibrated magnitudes with a user-provided set of comparison stars (as is done in AAVSO submissions).
  • export ensemble photometry results in the AAVSO Extended File Format for direct upload to WebObs.
• If you are working with exoplanet transit observations, stellarphot can turns the photometry into exoplanet transit light curves (see installation notes below).

Installation

stellarphot requires Python 3.10 or later.

You can install stellarphot with either pip or conda. If you are interested in stellarphot for exoplanet transit light curves, conda is recommended at the moment because of an issue with installing one of the dependencies.

• Install with conda using

  conda install -c conda-forge stellarphot
  

  If you are interested in exoplanet light curve fitting, also install pytransit using

  conda install -c conda-forge pytransit
  

• Install with pip. Most people want the full interactive experience (the Jupyter notebooks and widgets plus exoplanet fitting):

  pip install stellarphot[all]
  

  The optional dependencies are grouped into extras so you can install only what you need:

  • pip install stellarphot — base install. The headless/scriptable science engine (data structures, photometry, catalog access). Does not include the Jupyter/widget GUI.
  • pip install stellarphot[gui] — adds the notebook/widget interface.
  • pip install stellarphot[exoplanet] — adds exoplanet transit light-curve fitting (pytransit).
  • pip install stellarphot[all] — everything above.

Getting started with stellarphot

1. Start Jupyterlab from the command line: jupyter lab
2. Once JupyterLab opens in your web browser, open the Launcher (see Figure below)
3. Click on the notebook you want (see figure below) and follow the instructions in the notebook. Output files and the settings used to generate them will show up in the file browser

Questions?

Feel free to contact @mwcraig or @JuanCab with your questions about using stellarphot.

Contributors

Matt Craig 🐛 💻 🎨 🤔 🚧 🧑‍🏫 🔬 👀 ⚠️ ✅	Juan Cabanela 🐛 💻 🎨 🤔 🚧 👀 📖	madelyn914 🤔 📓	Abby 📓	MDeRung2021 🐛 📓	Tanner Weyer 💻 👀 📓	Emily Watson 🐛 📓
Adam Kline 💻 📓	Elias Holte 💻	P. L. Lim 🚧	clkotnik 🤔	Paige Meyer 📖	stottsco 💻	Isobel Snellenberger 💻 📓
Stefan Nelson 💻 📓	Nathan Walker 💻 📓	Jane Glanzer 💻 📓
Add your contributions

License

This project is Copyright (c) 2019-2024 The Stellarphot Team and licensed under the terms of the BSD 3-Clause license. This package is based upon the Astropy package template which is licensed under the BSD 3-clause license.