EK Draconis: Long-term photometry on Sonneberg Sky-Patrol plates

Abstract

We performed long-term photometry of the young solar analog EK Draconis (HD 129333) using 1030 blue-sensitive Sky-Patrol plates taken at Sonneberg Observatory from 1958 onwards. A secular dimming of mag/y beginning around 1975 was found. Hence, the recent trend first observed with Automatic Photoelectric Telescopes (APTs) is confirmed and traced back to the mid-seventies.