Effective spectroscopic diagnostics rely on the ability to convert a particular flux measurement into a physical interpretation. Knowledge of uncertainty is a central component of diagnostics. We present data from a simulated solar-like chromosphere, where we have addressed the question of whether degeneracy is a problem in mapping from a non-LTE

Accurate measurements of the surface brightness and its spectrophotometric properties are essential for obtaining reliable observations of the physical and material properties of planetary bodies. To measure the surface brightness of Ryugu accurately, we calibrated the optical navigation cameras (ONCs) of Hayabusa2 using both standard stars and

One of the most exciting areas of astronomical research today is the study of exoplanetary systems, engaging the imagination not only of the astronomical community but also of the general public. Since the Nobel-winning discovery of a giant planet around the Sun-like star 51 Pegasi (Mayor & Queloz, 1995), about 4000 extra-solar planets have been

In this thesis we explore the OTELO (OSIRIS Tunable Filter Emission Line Object) survey. OTELO is a very deep, pencil beam survey for the search of emission line sources by means of the tunable filters of the OSIRIS instrument, installed at the Gran Telescopio Canarias. A tomography scan method results in 2D, low-resolution pseudo-spectra for all

We present newly calibrated period-φ 31-[Fe/H] relations for fundamental-mode RR Lyrae stars in the optical and, for the first time, mid-infrared. This work's calibration data set provides the largest and most comprehensive span of parameter space to date, with homogeneous metallicities from -3 ≲ [Fe/H] ≲ 0.4 and accurate Fourier parameters derived