Hello,
I decided to re-visit my series of Nereid images and plot the predicted path of Nereid in The Sky 6 Pro, using data generated by the NASA JPL HORIZONS on-line solar system data and ephemeris computation service.
Well, to my surprise, the path that I had previously thought to be that of Nereid was several arc minutes away from the HORIZONS data as plotted in The Sky Pro 6 as a manually generated User Defined Object based on RA and DEC coordinates.
After a bit of head scratching and digging deeper into my data, I finally discovered the real Nereid, precisely where the HORIZONS system predicted it would be. The other moving object in the frame turned out to be a Minor Planet, designation 5796 1978 VK5.
So, after much investigation and plotting, finally, here is the corrected version. It looks as if the focus changed during the 5 x 20 minute exposures spanning 8:07pm to 9:53pm on 27th September 2008 as the track of Nereid “blurs” in the latter frames (see in-line cropped and enlarged animation).
Nereid animation:
WARNING: File size 1.6Mb
Cheers
Dennis