Development of Persistent Trains

[persistent train]

Photographs of persistent trains usually look like in the example above. When you take pictures of a persistent train with long exposure time, the structures will completely smear out due to the fast development of the train. In the best case, you can obtain a number of short exposure images (from which the sum image above was generated).

[persistent train]

With an image intensified video camera, however, you can record the development of persistent trains in full detail! The train shown here was recorded during the German Leonid expedition to Mongolia on November 16/17, 1998. Beside a number of unguided video systems we operated one camera that was especially devoted to persistent trains. Every time a fireball was seen, the operator immediately moved the camera in that direction.

Due to the extended infrared sensitivity of image intensifiers and the improved limiting magnitude (about 8 mag), the trains were visible much longer in the video than visually. In this case, a fireball of about -8 mag left a train, that remained visible for more than 5 minutes.

[persistent train]