# MINESweeper: Spectrophotometric Modeling of Stars in the Gaia Era

## TL;DR

MINESweeper is a Bayesian tool that jointly fits spectra and photometry to model isochrones, enabling precise stellar parameter and distance measurements, validated against benchmark stars, clusters, and Gaia data.

## Contribution

The paper introduces MINESweeper, a novel spectrophotometric modeling tool that integrates spectra and photometry within a Bayesian framework for improved stellar analysis.

## Key findings

- Derived stellar parameters agree with literature for benchmark stars.
- Distances and metallicities for star clusters match literature values.
- Spectrophotometric distances agree with Gaia parallaxes within uncertainties.

## Abstract

We present MINESweeper, a tool to measure stellar parameters by jointly fitting observed spectra and broadband photometry to model isochrones and spectral libraries. This approach enables the measurement of spectrophotometric distances, in addition to stellar parameters such as Teff, log(g), [Fe/H], [a/Fe], and radial velocity. MINESweeper employs a Bayesian framework and can easily incorporate a variety of priors, including Gaia parallaxes. Mock data are fit in order to demonstrate how the precision of derived parameters depends on evolutionary phase and SNR. We then fit a selection of data in order to validate the model outputs. Fits to a variety of benchmark stars including Procyon, Arcturus, and the Sun result in derived stellar parameters that are in good agreement with the literature. We then fit combined spectra and photometry of stars in the open and globular clusters M92, M13, M3, M107, M71, and M67. Derived distances, [Fe/H], [a/Fe], and log(g)-Teff, relations are in overall good agreement with literature values, although there are trends between metallicity and log(g), within clusters that point to systematic uncertainties at the ~0.1 dex level. Finally, we fit a large sample of stars from the H3 Spectroscopic Survey in which high quality Gaia parallaxes are also available. These stars are fit without the Gaia parallaxes so that the geometric parallaxes can serve as an independent test of the spectrophotometric distances. Comparison between the two reveals good agreement within their formal uncertainties after accounting for the Gaia zero point uncertainties.