Gerald Reczek reported on twitter, as he was walking his dog in the early morning hours, he saw a light rise up from the horizon and and disperse within 15 minutes.
Severe Weather Europe responded and speculated is likely be the Russian Fregat upper stage burn on the launch of AngoSat communications satellite, Angola's first satellite, from the Baikonur Cosmodrome in Kazakhstan.
https://en.wikipedia.org/wiki/AngoSat_1
According to SWE similar sightings were made in Romania.
No reason is given why a Russian rocket from Kazakhstan would be seen in Austria. Similar explanations were produced when the Norway Spiral appeared over Oslo in 2009.













Comment: The Russian rocket explanation seems unlikely. Whatever the immediate cause, perhaps this has something to do with the luminescence: See: SpaceX rocket launch spooks Californians with eerie glowing trail (VIDEOS)