A new class of rapidly pulsating star -- I. EC 14026 -- 2647, the class prototype

We report the discovery of small-amplitude, very rapid light variations in the sdB binary, EC 14026 — 2647. The variations, probably due to pulsation of the sdB star, have an apparently stable main period near 144 s with a semi-amplitude of ∼ 0.012 mag. There is good evidence for a period near 134 s with a semi-amplitude of ∼ 0.004 mag; the latter might be variable. We regard this star as the prototype for a new class of variable which we refer to as EC 14026 stars.