The EC 14026 stars - XIII. EC 05217-3914 and KUV 0442+1416

We report the discovery of short-period oscillations in the sdB stars EC 05 217-3914 and KUV 0442+1416, establishing them, as members of the EC 14026 s tars, a recently discovered class of sdB pulsators. The pulsation periods a nd atmospheric parameters for both stars are determined. The results are: p eriods of 218, 216 and 213 s, T-eff, = 31 300 + 250 K and lo,og = 5.76 +/- 0.06 for EC 05217-3914; periods of 231, 216 and 184 s, T-eff, = 30 900 +/- 400 K and log g = 5.72 +/- 0.1 for KUV 0442+1416. Considerable substructure in the periods is apparent in both stars when several nights of data are c ombined. KUV 0442+1416 is significantly reddened. The evolutionary status of the 13 well-studied EC 14026 stars is examined. All stars except PG 1605+072 appear to be core He burning. The positions of the pulsators and the apparently constant stars are plotted in the log g-T -eff,ff plane. Apparently constant stars mingle with the pulsators so that there is no well-defined instability strip. This poses a significant challe nge to the Fe driving mechanism of Charpinet et al. Five out of the 13 pulsators are obvious binaries.