DAOPHOT-MCMC is a modified version of the subroutine NSTAR.F which implements a Markov chain Monte Carlo (MCMC) routine for fitting crowded stellar positions and fluxes. This code is installed and implemented within the overall DAOPHOT-II structure (note: you must have a pre-installed version of DAOPHOT-II). Instructions and descriptions of the original software suite can be found in the DAOPHOT-II User's Manual (direct download).

Some of the DAOPHOT-MCMC functionality includes:

• Simultaneous 1-star, 2-star, and 3-star PSF fitting.
• Metropolis-Hastings routine to deliver posterior probability distributions for positions, separations, flux ratios, and total flux.
• Best-fit $\chi^2$/pixel map.
• (Optional) constraints on the total flux and separation(s) for 2-star and 3-star fitting.
• (Optional) shell scripts (.sh) to automate MCMC runs on large datasets.

Detailed information can be found in the DAOPHOT-MCMC User's Manual here.

A Python wrapper (with added functionality) has also been developed, you can find it here.

If you find this code useful in your research, please cite Terry et al. 2021