We present the results of a study to discover prospective new white dwarf-L dwarf binaries as identified by their near-infrared excesses in the UKIDSS catalogue. We obtained optical spectra to validate the white dwarf nature for 22 of the candidate primary stars, confirming ten as white dwarfs and determining their effective temperatures and

Eight planetary nebulae have been identified as 'born-again', a class of object typified by knotty secondary ejecta having low masses (${\sim}10^{-4}$ M ☉) with nearly no hydrogen. Abell 30, the archetype of the class, also belongs to a small subset of planetary nebulae that exhibit extreme abundance discrepancy factors (where Abell 30 is the most

Astronomical infrared spectral features at ~6.6, 9.8 and 20 micronm have recently been suggested as being due to the planar graphene form of C24 carbon cluster. Here we report density functional theory and coupled cluster calculations on wavefunctions stability, relative energies, and infrared spectra of four different types of C24 isomers

Temperature inversion layers are predicted to be present in ultra-hot giant planet atmospheres. Although such inversion layers have recently been observed in several ultra-hot Jupiters, the chemical species responsible for creating the inversion remain unidentified. Here, we present observations of the thermal emission spectrum of an ultra-hot

Massive early-type galaxies (ETGs) are mainly populated by old stars that dominate the optical spectral range. We analyse optical and near-ultraviolet (NUV) absorption lines from integrated spectra of massive ETGs to study its young stellar content, thanks to the extreme sensitivity of the NUV to young stars. We find that young stellar populations