It's surprising how many planes pass through the view during a typical timelapse session. Also satellites and meteorites. All of which have to be photoshopped out of the individual 15-second frames (usually 3 or 4 frames per occurence, except for meteorites which only show up for one frame).
The planes have a blinking light pattern, as seen here, whereas satellites and meteorites are a more solid line.
The bright star to the left of the plane trail is Capella.