A robust and extended characterization of the point spread function (PSF) is crucial to extract the photometric information produced by deep imaging surveys. Here we present the extended PSFs of the Sloan Digital Sky Survey (SDSS), extending over 8 arcmin in radius for all filters (u, g, r, i, z). We illustrate with an example how the PSF models

Dwarf ellipticals are the most common galaxy type in cluster environments; however, the challenges associated with their observation mean that their formation mechanisms are still poorly understood. To address this, we present deep integral field observations of a sample of 31 low-mass (10 7.5 < M ⋆ < 10 9.5 M ☉) early-type galaxies in the Fornax

The measurement of distances to individual stars with Gaia is enabling the construction of deep colour-magnitude diagrams (CMD) for large volumes within our Galaxy in absolute magnitudes. Comparison with models (CMD-fitting) has allowed us to obtain the most detailed star formation history (SFH) of the bubble of 2 kpc around the Sun. Surprisingly

Metal-poor stars are important tools for tracing the early history of the Milky Way, and for learning about the first generations of stars. Simulations suggest that the oldest metal-poor stars are to be found in the inner Galaxy. Typical bulge surveys, however, lack low metallicity ( $\rm {[Fe/H]} \lt -1.0$ ) stars because the inner Galaxy is

The central star of ETHOS 1 is known to be a post-common-envelope binary. Simultaneous modelling of newly-acquired light and radial velocity curves reveal the binary to comprise of a hot and massive pre-white dwarf with a low-mass main-sequence companion. Preliminary results indicate that the nebular progenitor is one of the most massive known

One-dimensional radiative transfer (RT) calculations suggested that the scattering polarization profiles of the Hα line are very sensitive to the strength and structure of the chromospheric magnetic field. Here we present unprecedented spectropolarimetric observations of the Hα line obtained with ZIMPOL-3 at IRSOL. The linear polarization profiles