Tuesday, August 17, 2010

& then there was light!!

The first job for the day was to get the Apogee stage assembly installed on top of the tracker...

A crisp Karoo sunset viewed from the CCAS tower was followed by the squaring up of the camera stage.

A small mirror (the one from the old paddle mirror in fact - flash back about a year for that story) was placed on the stage & the alignment telescope's auto-reflection observed.  Rotating the Rho stage gave feedback for the "Rho Boys" (Charl & Ockert) to adjust the tip & tilt of the camera stage.

With the stage appropriately set up, the Apogee camera was put in position & fired up.

After a primary mirror alignment, the anxious team looked on, willing the telescope back to life as it attempted to track stars for the first time in 16 months... 

Nothing's ever simple in this game, but a while later we had stationary (albeit hugely out of focus) stars in the field of view!

The out of focus images were used to tweak the auto-collimator offsets to reduce coma & then adjustment of the tracker in Z sorted out the focus to give reasonable looking stars.  Sadly, by that stage the seeing had deteriorated to >2.5 arcsec so we couldn't really assess the Image Quality, but overall it was a Fantastic Night & we're keeping fingers crossed for better conditions tomorrow...

A characteristically cautious observation from Darragh was: "Well - we haven't made anything worse!" - which really is quite remarkable when you consider the extent of the SAC interventions & our collective previous experience in this business!