We use the SMASH survey to obtain unprecedented deep photometry reaching down to the oldest main-sequence turn-offs in the colour-magnitude diagrams (CMDs) of...

The Kepler and TESS missions have demonstrated that planets are ubiquitous. However, the success of these missions heavily depends on ground-based radial...

If thick disks are ubiquitous and a natural product of disk galaxy formation and/or evolution processes, all undisturbed galaxies that have evolved during a...

The variation of the mass-to-light M/L ratios of early-type galaxies as a function of their luminosities L is investigated. It is shown that the tilt β=0.27 (in...

NGC 4013 is a nearby Sb edge-on galaxy known for its "prodigious" H I warp and its "giant" tidal stream. Previous work on this unusual object shows that it...

We present a wide field V-band imaging survey of approximately 1 deg2 (~7.2~h-275 Mpc2) in the direction of the nearby cluster of galaxies Abell 2151 (the...

We present a light curve of C/1995 O1 (Hale-Bopp) compiledfrom more than 3000 visual observations of the comet made by members of the The Astronomer Group world...

R-band surface photometry is presented for 171 late-type dwarf and irregular galaxies. For a subsample of 46 galaxies B-band photometry is presented as well. We...

Context: Determining the parameters of massive stars is crucial to understand many processes in galaxies and the Universe, since these objects are important...