DS (70–180 Å) fluxes over the 34 day observation of β Cet and, on the same scale, earlier pointings on β Cet (1994 September) and μ Vel (1998 March; containing the large flare that motivated the present study). Each point represents the unocculted portion (~3 ks) of one satellite orbit. Narrow horizontal stripes in each time series indicate an estimated low‐activity level. Alternating vertical shaded bands in the year 2000 light curve mark the individual time segments from which SW spectra were extracted. The 1994 September DS observation was adjusted to compensate for the influence of the dead spot.