MCPM extracts K2 photometry in dense stellar regions; the code is a modification and extension of the K2-CPM package (ascl:2107.024), which was developed for less-crowded fields. MCPM uses the pixel response function together with accurate astrometric grids, combining signals from a few pixels, and simultaneously fits for an astrophysical model to produce extracted more precise K2 photometry.

This general complex polynomial root solver, implemented in Fortran and further optimized for binary microlenses, uses a new algorithm to solve polynomial equations and is 1.6-3 times faster than the ZROOTS subroutine that is commercially available from Numerical Recipes, depending on application. The largest improvement, when compared to naive solvers, comes from a fail-safe procedure that permits skipping the majority of the calculations in the great majority of cases, without risking catastrophic failure in the few cases that these are actually required.