The Necklace nebula is a bipolar, post-common-envelope planetary nebula, the central star of which has been shown to have a dwarf carbon star companion. We aim to understand the origins of the Necklace and its dwarf carbon central star. We study the carbon abundance of the nebula through far-ultraviolet spectroscopy obtained with the Hubble Space Telescope. Furthermore, through simultaneous modelling of multi-band light and velocity curves, we attempt to constrain the parameters of the central star system. Puzzlingly, we find that the region of the inner nebula observed with the Hubble Space

Sub-Neptunes - planets larger than Earth but smaller than Neptune - are the most common type of planet in our Galaxy, yet they are entirely absent from our own Solar System. This absence makes them a major focus for astronomers seeking to understand planetary formation and evolution. We recently conducted an international study, as part of the THIRSTEE project, to characterize two such planets orbiting very similar small, cool stars known as M dwarfs: TOI-521 and TOI-912 . THIRSTEE is an observational-based program that aims to shed light on the sub-Neptune population by providing an

Dormant black holes in X-ray transients can be identified by the presence of broad Hα emission lines from quiescent accretion discs. Unfortunately, short-period cataclysmic variables can also produce broad Hα lines, especially when viewed at high inclinations, and are thus a major source of contamination. Here we compare the full width at half maximum (FWHM) and equivalent width (EW) of the Hα line in a sample of 20 quiescent black hole transients and 354 cataclysmic variables (305 from SDSS I to IV) with secure orbital periods (Porb) and find that: (1) FWHM and EW values decrease with Porb