2023RNAAS...7..158M

The analysis of four spectra of the B7 He-weak Si star HD 49333 recorded by the SWP camera on board the International Ultraviolet Explorer reveals variations of the far-ultraviolet spectral energy distribution shortwards of 1700 Å over slightly more than 1 day, ie. about 46% of the rotational period. Several Si II, Si III and Si IV vary consistently. Silicon must be distributed in a non uniform manner over the surface of HD 49333 so as to modulate the FUV flux over the rotational period. The profile of the resonance line of C II at 1335 Å does not vary at these two rotational phases.