A key component of the Dark Energy Spectroscopic Instrument (DESI) survey validation (SV) is a detailed visual inspection (VI) of the optical spectroscopic data to quantify key survey metrics. In this paper we present results from VI of the quasar survey using deep coadded SV spectra. We show that the majority (≈70%) of the main-survey targets are

Context. Detecting a planetary companion in a short-period orbit through radio emission from the interaction with its host star is a new prospect in exoplanet science. Recently, a tantalising signal was found close to the low-mass stellar system GJ 1151 using LOFAR observations. Aims: We studied spectroscopic time-series data of GJ 1151 in order to

The 4MOST–Gaia Purely Astrometric Quasar Survey (4G-PAQS) will carry out the first large-scale, colour-independent quasar survey selected solely on the basis of astrometry from Gaia. Our main objective is to quantify the selection effects of current colour-selected samples. These colour-selected samples bias our view of the neutral gas and its

The Transiting Exoplanet Survey Satellite (TESS) mission searches for new exoplanets. The observing strategy of TESS results in high-precision photometry of millions of stars across the sky, allowing for detailed asteroseismic studies of individual systems. In this work, we present a detailed asteroseismic analysis of the giant star HD 76920

The dayside brightness spectrum of a highly irradiated transiting brown dwarf KELT-1b is challenging to explain based on current brown dwarf atmosphere models. The spectrum has been measured from observations spanning ten years and covering high-precision secondary eclipses and phase curves from space in blue-visible (CHaracterising ExOPlanet