SImMER: A Pipeline for Reducing and Analyzing Images of Stars

December 2022 • 2022PASP..134l4501S

Authors • Savel, Arjun B. • Hirsch, Lea A. • Gill, Holden • Dressing, Courtney D. • Ciardi, David R.

Abstract • We present the first public version of SImMER, an open-source Python reduction pipeline for astronomical images of point sources. Current capabilities include dark-subtraction, flat-fielding, sky-subtraction, image registration, FWHM measurement, contrast curve calculation, and table and plot generation. SImMER supports observations taken with the ShARCS camera on the Shane 3 m telescope and the PHARO camera on the Hale 5.1 m telescope. The modular nature of SImMER allows users to extend the pipeline to accommodate additional instruments with relative ease. One of the core functions of the pipeline is its image registration module, which is flexible enough to reduce saturated images and images of similar-brightness, resolved stellar binaries. Furthermore, SImMER can compute contrast curves for reduced images and produce publication-ready plots. The code is developed online at and is both pip- and conda-installable. We develop tutorials and documentation alongside the code and host them online. With SImMER, we aim to provide a community resource for accurate and reliable data reduction and analysis.


IPAC Authors


David Ciardi

Senior Scientist