A study led by the NCU Transient Group investigates a mysterious class of white dwarf explosions known as “Super-Chandrasekhar” explosions (or 03fg-like SNe Ia) and reveals their extraordinary ultraviolet (UV) properties. Compared to normal SNe Ia, these events exhibit significantly brighter and broader light curves, along with distinct spectral features. Using UV spectra obtained with the Swift satellite, we find that 03fg-like SNe show a pronounced UV excess, which is challenging to explain with current explosion models for normal SNe Ia. Our analysis suggests that interaction with circumstellar material (CSM) could provide a promising explanation for their unique UV characteristics. This work has been published in MNRAS.
