mphot

mphot is a Python package to model photometry for ground or space-based astronomy. Exposure time calculator (ETC) built in.

How it works

Simply put,

• it combines user submitted [telescope * filter * camera qe] efficiencies with generic stellar models and sky transmission/radiance models (for Paranal, 2400m) to generate integrable grids of stellar fluxes and sky radiances.

• Then, mphot uses the grids to interpolate between different

  • atmospheric parameters (PWV, airmass)
  • target star parameters (effective temperature + distance)

• using user submitted

  • telescope/site parameters (primary and secondary diameters, site seeing)
  • camera parameters (plate scale, dark current, read noise, well depth, target well fill, read time)

• to calculate the ideal exposure time and expected precision for a given observation.

Please see the examples for more details on how to use mphot. For further details on the models used, please see https://doi.org/10.1117/12.3018320.

Note, it uses stellar parameters from "A Modern Mean Dwarf Stellar Color and Effective Temperature Sequence". Temperatures between 1278 K to 3042 K are calibrated for the SPECULOOS target list with 2MASS (see Figure 4.7 in "Optimised ground-based near-infrared instrumentation for robotic exoplanet transit surveys").

Installation

You can install mphot in a Python (>=3.11) environment with

pip install mphot

or from a local clone

git clone https://github.com/ppp-one/mphot
pip install -e mphot

You can test the package has been properly installed with

python -c "import mphot"

Web demo

mphot runs in the browser through Pyodide. No server does the work. To run it on your machine:

python web/build.py
python -m http.server --directory web 8000

Then open http://localhost:8000/. See web/README.md.

Attribution

If you find mphot useful for your research, please cite Pedersen et. al 2024. The BibTeX entry for the paper is:

@inproceedings{pedersen2024infrared,
  title={Infrared photometry with InGaAs detectors: First light with SPECULOOS},
  author={Pedersen, Peter P and Queloz, Didier and Garcia, Lionel and Schacke, Yannick and Delrez, Laetitia and Demory, Brice-Olivier and Ducrot, Elsa and Dransfield, Georgina and Gillon, Michael and Hooton, Matthew J and others},
  booktitle={Ground-based and Airborne Instrumentation for Astronomy X},
  volume={13096},
  pages={1146--1167},
  year={2024},
  organization={SPIE}
}