Monday, October 26, 2015

Align Align Align

After being clouded out last night, and poor weather all night and all morning, I really didn't expect there to be an opportunity to come back to the observatory over the weekend.  However the weather cleared up in the afternoon and started to look quite clear.  A check of the satellite map showed the cloud moving away  and what looked like clear skies heading our way.

Jonathan wasn't available so  I headed out there myself to see whether I could make a start on the elusive (so far) polar alignment of the Paramount.  All the failed nights in here are certainly paying off because it takes very few minutes to be up and running with the scope.  Once we have a pointing model set up and the dome slaved to the scope (planned as soon as we have a somewhere close polar alignment) then it should be a breeze to get everything ready for an evenings observing.

First order of business was to see if I could get a rough align by clearing the previous sync and pointing model and telling the scope (through TheSkyX) to go to a star around the south celestial pole (I chose one of the three stars in a small triangle in Octans) .  Sounds simple - but no go - the scope ended up pointing somewhere near zenith.

Still encouraged by the low rate of drift, I decided to jump straight into the drift alignment process hoping that we were close enough for this to work.

Test image of 47 Tucanae (NGC104)
Part way through the clouds came in giving an opportunity to write up last nights blog, and threatening to shut down the operation again - fortunately tonight though they lightened off and then cleared completely. Backwards and forwards between the eastern horizon and the meridian I gradually tweaked the altitude and azimuth screws (only going the wrong way once thanks to my cheat notes i chalked on the pier ("star goes up, tighten this screw" and "up=higher") - until eventually after a few iterations there was no real noticeable movement for 5+ or so minutes  each side. Of course this can (and will be) improved and refined - but certainly a good starting point. 

It was getting late, and a little chilly in the dome but I decided I should at least take a picture of something before I locked up. The image of 47 tuc certainly isn't the best in the world, but  it representsthe completion of  another successful evening's work out at Kumeu, and another step on the journey to breath new life and bring new blood into the observatory so we can really start making use of this great facility.


Friday, October 23, 2015

Getting set up for a polar align (again)

With the mount now oriented on the pier close to the true north/south line in azimuth, Jonathan and I seized the opportunity of what looked like the first possible fine night in what seems like weeks.

Jonathan was opened up and powered on before I arrived, and it looked like we might be ok despite a few gathering clouds.  having had the OTA off the mount (and the mount of the pier!) it looked  like we'd managed to get the finder misaligned too.

Having spent far too long on previous sessions trying to align the finder with the OTA using the CCD (when the alignment was so far off it was just about impossible to work out where we were pointing,) the first order of business was to swap the CCD for a good old eyepiece.

Utilising a handy local house with it's lights on, we quickly got the finderscope aligned with the OTA and switched back to the CCD.  After cooling the CCD we soon confirmed that Jonathan had managed to get the finder spot on as we could get a star right in the centre of the CCD chip by moving the scope so that it was in the finder crosshairs.

All looking good, we noticed now that the drift of the stars was markedly reduced across the image - a good sign that we were now much closer to alignment.  We also noticed that the clouds had started to roll in ....

Whilst the clouds rolled over, we took the opportunity to tidy up a few of the cables more and also install a safety wire on the CCD - hoping that the weather would clear enough to have another crack at the polar alignment

Unfortunately, a look at the satellite image of the clouds confirmed there was more to come so we called it a night - warmed up the CCD, closed the dome and shut everything down...

Encouraged though by the discovery that the star drift was definitely smaller we were looking forward to coming back again at the next clear opportunity.


Tuesday, October 20, 2015

New lease of life

The Nustrini C14 on the Paramount GT-1100S
So after a short period of very little activity, there is now a serious push to get Kumeu back into being an active observing site.  With a new group of members from Auckland Astronomical Society looking to do some more research oriented projects, and a steadily growing enthusiastic group of astrophotographers, the time is certainly right to dust off the dome and get some activity going.

The other thing that has happened that is very exciting for the observatory is that the old (yet reliable) "push to" fork mount for the C14 "Nustrini" OTA has now had a fairly serious upgrade to a Software Bisque Paramount GT-1100S - that belongs to Stardome and became available due to the upgrade of the research dome equipment there earlier in the year.

Having a fully robotic mount means that the startup process is dramatically shortened, and also observing sessions should be much easier (and able to be fully controlled from outside the dome itself).

I will be posting updates regularly here as work progresses, and once we are back into the swing of observing regularly, there should be regular logs of the sessions and observations.

Steve Hennerley
Curator of Instruments, Auckland Astronomical Society

Thursday, October 8, 2015

Putting it back together

Fun with serial cables
Jonathan and I had a productive (if occasionally frustrating) evening out at Kumeu.  Although the weather was awful (so we didnt actually open the dome) Jonathan installed the finder and the shipping/lock and safety bolts, we have had the computer controlling the mount using (I need to make up a more permanent connector), confirmed the dome rotates under power, and also confirmed the Velleman board (used for the dome rotation system) works by using the test program and i can slew and reverse the dome fro the PC
Still do do: (not exhaustive)
  • Permanent wiring for serial connection PC to Paramount
  • Connect and Set up TCF
  • Route 12v power cables for dome rotation and dew heater
  • Tidy all cables box for Velleman board
  • Connect camera
  • Set up Lesvedome 
  • Polar alignment
  • TPoint Mapping

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