UV SURVEY OF DELTA-SCUTI STARS - FINAL RESULTS AND OPEN PROBLEMS

The results obtained from our IUE observations of some delta Scuti sta rs and in particular 71 Tau and 69 Tau are reviewed. 71 Tau is the sec ond brightest X-ray source of the Hyades cluster; on the contrary 69 T an, very similar to 71 Tau in the optical range, does not show X emiss ions. The complex and in somewhat controversial scenario obtained from this survey is also discussed. In particular we consider the X-ray em ission detected in some delta Scuti with respect to the chromospheric activity level as measured through the MgII line and to other stellar parameters.