SIGHTING: BOCHUM, NORDRHEIN-WESTFALEN (GERMANY)

Witness Testimony

"Hi,like 2 months ago (19th or 20th june) i shot some random pictures out of my window of the night sky.After downloading it to the pc i noticed some strange/weird line at the upper left corner. I still cant figure out what it is (i'm a physics student), so here you are ;)I did not see the line with my own eyes, just with the camera. I cant remember if i did not look hard enough or if it just was not visible.Its on three pictures: 59, 60 and 62. Picture 61 doesnt show the area in which the line is or would have been located. But 58 and 57 does show the area, without the line.If you try to get the position of the line by comparing it to the position of two stars right to the line you will notice that its moving downwards with increasing picture number. Sadfully picture 62 was the last one, so i dont know cleary how long it was 'visible'.I cant remember the time between the pictures, but it could be something between 7 and 40 seconds each. Which means that it would have been at the sky 28 seconds upto 160 seconds. So its definitely no meteor or something.Could you please tell me what this line is or by what it is caused?thank you!regards, nico"