Warm and somewhat hazy.  High today was 85 – predicted low 65.  Medium to high humidity.

Rig #1: Deneb & P-Cyg

I focused the collimator lens and set the grating micrometer so that the Neon 6532 line was a close to column 558 as possible.  That is where it was located a few nights ago when I did lamp flats.  To measure – show the crosshairs and measure at the central Y position.  Micrometer reading is 1578.0.  I also re-focused the guide camera, looks like the best focus spot on the slit is around x=115.  For the Si lines in Deneb set the micrometer to 1511.2 – place the Ne 6334 line at around 559.

I need to come up with a good cadence.  Basically need to start with Zeta Aql (ref star) in Ha – then to P Cyg, then to Deneb.  Change grating micrometer for Si lines – get Deneb, then back to Zeta Aql.  Then change micrometer back for H-alpha and back to P-Cyg.  Noel says he needs 3 to 4 sets of P-Cyg images around H-alpha – but I’m not sure what sort of time separation is needed for each set.  Tonight I got two sets – though I almost forgot to get Zeta Aql at the setting for the Si lines!  Done at around 2:30am.

Rig #2:  UX UMa

I got the first sequence started for UX UMa around 9:35pm – gotta love those late summer sunsets!  Seeing is around 2.0 arcseconds, perhaps a bit better.

Guidestar Fade Issues

One thing that is still and always has been a PIA with Maxim – the dreaded “guide star fade” issue.  Despite the star being clearly visible in the guider image with reasonable s/n (in this case s/n was about 10) the guider function cannot find the star in the image.  I lost about 15 minutes of imaging (right during eclipse, of course) due to what is a way too common problem.  Lots of discussion about this on the Maxim Yahoo group site as there is every time there is a new release for Maxim DL (I just installed 6.03 on the main computer – though the observatory computer is running 5.24).  But it’s been a problem for as long as I’ve used Maxim – which is about 8 years now!

Out at about 2:30am.  Excellent night overall.


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