Startrail showing both celestial hemisphere rotation

[Helen]

In March I was fortunate enough to go on a University field trip to the Cala Alto Observatory in southern Spain.  It was a fantastic week for many reasons.  We got to use a 2.3m scope for 5 nights so got some serious data collection done on all sorts of targets (comets, asteroids, exoplanets, clusters, galaxies, Jupiter etc).  But also there was some less serious stuff - usually involving standing in snow, battling the windchill, and freezing  - learning how to do widefield and timelapses.  On the last night I decided to set up my camera just outside the library which was acting as our control room and do some timelapse, showing comings and goings.  Orion was very conveniently placed    When I processed the pictures I realised I may have had some other nocturnal visitors as I lost a lot of subs through vibration (eek - relieved the camera stayed upright).  As a result my timelapse isn't as smooth as I'd hoped.  I also processed as a startrail - and this is where the interesting thing showed up.  Normally startrails are shown around Polaris (and I have a couple of those), but this time I was looking south west and so the trails show rotation about both north and south poles  An interesting effect I think.

Two versions - one with the foreground trees illuminated by a car and the automatic entrance light, and the other taking out those frames.  (I need to do more reading up now on batch processing timelapses though - any tips very welcome!)

 

Also the timelapse video.

Helen

20s subs with a Sony 6500 and a Zeiss 16-70 lens at f4

Helen

[laser_jock99]

Looks like a very productive trip. The star trails curving in different directions is a curious effect and kind of defies logic. But it's also good demonstartion of the 'celestial sphere'.