A Warshawski flare was a sudden spike in the energy output of a starship's Warshawski sail.
It was usually caused by the overloading (and/or destruction) of an alpha node, but could also be artifically created by using all alpha nodes of an impeller ring to project a suitable power pulse; this could take a good thousand hours off their projected service life.
The crew of the Manticoran Q-ship Wayfarer used a simulated flare to convince Andre Warnecke's forces that they were a crippled freighter. (HH6)