The Gregor Infrared Spectrograph (GRIS) is installed at the Gregor telescope at Observatorio del Teide, Spain. The instrument started observations in 2012 and underwent several upgrades in the following years. Currently, it is experiencing the most significant upgrade so far, which includes, among other things, adding two optical channels to

We obtain a quantitative star formation history (SFH) of a shell-like structure ('shell') located in the northeastern part of the Small Magellanic Cloud (SMC). We use the Survey of the MAgellanic Stellar History to derive colour-magnitude diagrams (CMDs), reaching below the oldest main-sequence turnoff, from which we compute the SFHs with CMD

Multiplanetary systems spanning the radius valley are ideal testing grounds for exploring the different proposed explanations for the observed bimodality in the radius distribution of close-in exoplanets. One such system is HIP 29442 (TOI-469), an evolved K0V star hosting two super-Earths and one sub-Neptune. We observed HIP 29442 with CHEOPS for a

The magnetic and rotational properties of solar-like stars are strongly coupled due to the interaction of rotation and convection in their outer envelopes, which fuels their magnetic dynamos and, as a consequence, their magnetic activity cycles. Thanks to the large number of Kepler targets with measured rotation periods and photometric magnetic

Big datasets are becoming increasingly important in astrophysics due to new surveys continuously observing our night sky. A prominent example of an observatory that will produce a large data stream is Vera C. Rubin LSST, designed to simultaneously monitor the southern night sky in six colors. Unsupervised machine learning (ML), a method of learning

During the late subgiant/early giant stage, stars undergo fast evolutionary changes such as the readjustment of their internal rotation. It is of paramount importance to study this phase, in particular to understand the transport of angular momentum from the cores of stars to their envelopes. Bridging this knowledge gap is crucial to obtain more