Nova Herculi 2021 as an intermediate polar

We report the results of observations of Nova Herculi 2021 -V1674 Her.The object is characterized by several exceptional properties.The progenitor was identified as an intermediate polar.The speed of the outflow reached 10000 km s -1 .The brightness decline was exceptionally rapid: t2 ∼ = 1.2 d, t3 ∼ = 3 d.The pulse spin signal was detected in photometry soon after the nova eruption.Extremely fast spin-up of the white dwarf rotation was measured.Despite challenges in cycle counting, we successfully constructed the O -C diagram of spin pulse maxima based on three seasons of observations.The result suggests a stable spin acceleration, with an anticipated gradual decline over the next decades.Additionally, we investigated the evolution of the orbital period.