This work shows that aspherical surfaces obtained by the general equation of stigmatic sequential optical systems are very sensitive to wavelength. The application these surfaces to broadband lens-based systems is limited by the system aperture.

Big Datasets are becoming more and more prominent in the field of astrophysics with new powerful telescopes and surveys capturing parts of our night sky in an almost continuous fashion. Consequently, unsupervised Machine Learning is key to getting first insight into this abundance of data. We present our results on the performance of unsupervised

Here, we report an ensemble study of 214 A- and F-type stars observed by Kepler, exhibiting the so-called hump and spike periodic signal, explained by Rossby modes (r modes) - the hump - and magnetic stellar spots or overstable convective (OsC) modes - the spike, respectively. We determine the power confined in the non-resolved hump features and

Ultracompact X-ray binaries (UCXBs) are a distinctive but elusive family of low-mass X-ray binaries (LMXBs) characterised by their tight orbits and degenerate donor stars. Here we present UltraCompCAT, the first online and comprehensive catalogue of UCXBs. The initial version of UltraCompCAT comprises 49 sources, including 20 confirmed UCXBs (those

The main scientific goal of TESS is to find planets smaller than Neptune around stars that are bright enough to allow for further characterization studies. Given our current instrumentation and detection biases, M dwarfs are prime targets in the search for small planets that are in (or near) the habitable zone of their host star. In this work, we

We report the discovery and validation of two long-period giant exoplanets orbiting the early K dwarf TOI-4600 (V = 12.6, T = 11.9), first detected using observations from the Transiting Exoplanet Survey Satellite (TESS) by the TESS Single Transit Planet Candidate Working Group. The inner planet, TOI-4600 b, has a radius of 6.80 ± 0.31 R ⊕ and an