Thursday night I went up the Heathcote area to test some astro equipment.
One of the things I was testing was a little sky tracker that I made. So, I set it up on a very sturdy tripod and I attached my old Canon compact in manual mode taking a 20 second exposure every 42 seconds. All went well and I let it run until the morning.
On my way home on Friday morning I heard on the radio about the Leongatha earthquake, and today it occurred to me that I should see if there is a disturbance in the star trails recorded. My intention was just to stitch together 660 frames into a 22 second video to see if my tracking was smooth. Watching the video for any wobbles I did notice a small jump, a couple of hours into the recording, that was suspicious. Because my polar alignment was not perfect, the stars were slowly drifting and that made it possible to produce star trails by doing a max combine without alignment. When I did that, it became easy to see the disturbance in the little star trail arcs.
Unfortunately, the time was not set on the camera so I can't be sure that it was the earthquake. I had been very careful not to kick the tripod, and no one else went near it.
The attached image is a 100% crop representing over 7 hours of field rotation due to polar misalignment.
