Protoneutron stars formed during core-collapse supernovae are hot and dense environments that contain a sizable population of muons. If these interact with new long-lived particles with masses up to roughly 100 MeV, the latter can be produced and escape from the stellar plasma, causing an excessive energy loss constrained by observations of SN

https://youtu.be/yfkrfjnIuqg?si=TMZiL0Limnxal2Ex

We present the results of new time-series photometric observations of 29 pre-white dwarf stars of PG 1159 spectral type, carried out in the years 2014-2022. For the majority of stars, a median noise level in Fourier amplitude spectra of 0.5-1.0 mmag was achieved. This allowed the detection of pulsations in the central star of planetary nebula A72

This talk is on YouTube at this link: https://www.youtube.com/watch?v=aHt0jssgDCE

Accreting white dwarfs are known to show signatures of wind-type outflows in the ultraviolet. However, at optical wavelengths, wind detections have only been reported for a few sources. We present GTC-10.4 m optical spectroscopy of four accreting white dwarfs (BZ Cam, V751 Cyg, MV Lyr, and V425 Cas) observed during luminous epochs, when their

We present the first measurements of Lyman-α (Lyα) forest correlations using early data from the Dark Energy Spectroscopic Instrument (DESI). We measure the auto-correlation of Lyα absorption using 88 509 quasars at z > 2, and its cross-correlation with quasars using a further 147 899 tracer quasars at z ≳ 1.77. Then, we fit these correlations