Daniel Galán Diéguez is an astrophysicist specializing in stellar spectroscopy, with a particular focus on the effects of rotation on the physical properties and spectral classification of massive stars. His research addresses how rotational and tidal distortions influence stellar structure, surface temperature distributions, and emergent spectra, providing critical insights into the evolution and observable characteristics of massive stars.

He is a key developer of SPAMMS (Spectroscopic PAtch Model for Massive Stars), a computational tool that combines LTE and NLTE model grids (Kurucz, TLUSTY, FASTWIND) to derive precise stellar parameters from high-resolution spectra of deformed stellar surfaces. SPAMMS enables detailed modeling of stars with complex shapes and surface inhomogeneities, making it particularly valuable for studying tidally and rotationally distorted systems (such as close binaries and rapidly rotating stars).