Abstract
Abstract
The analysis of eighteen spectra of the B6 He-weak star HD 142990 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 about 6 hr, ie. about 25% 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 142990 so as to modulate the FUV flux over the rotational period. The low resolution spectra also confirm this variability.
Publisher
American Astronomical Society