Saturday, January 9, 2010

Notes from Journal Page: January 9, 2010

It’s finally clear, but very cold.  Right now the outside temperature is showing (only) -12 but the forecast says it will drop to -21 tonight, hitting the low about 10:00 PM and staying there.

I went outside this afternoon to clear the snow and ice from the dome cover and shovel the deck clear around the dome door, and went into the dome and turned on the heater at the “keep from freezing” setting, which will very gently warm the interior of the dome just slightly, holding it a few degrees above freezing, which should make the startup of the mount, gears, motors, etc., a little easier.

Tonight’s plan is to gather more data for the B33 region that I started a couple of weeks ago.  I still need all three RGB colours, and would also like some straight luminance to serve as a base for the Ha capture I already have.  I will also do a quick RGB image of a G2V star, if I can find a convenient one quickly, to calibrate the colour mix.

Plan for tonight, to be modified no doubt:

  • Start about 7:30 PM – as soon as Castor/Pollux are clear of the house
    • Started early, more like 6:50
  • Take a bunch of 2-minute darks (for the G2V) and a bunch of 10-minute darks for the RGB.
    • Taking 2, 5, and 10-minute darks, total 55min elapsed
  • Take RGB of a G2V star in the general area of Orion.
    • HIP 24336, HIP 29248, HIP 23831 are near Orion
    • HIP 29248 looks best – nicely separated.  RA 6-10-39  Dec +17-55-56 (now)
      • It’s GSC 1318:1060, which Maxim can find.
  • Take flats for R, G, B, and luminance
    • Done.  Had to adjust exposures because light is fading
    • Flats show really bad speckling esp on Lum – need to clean eithter the filters or the ccd
  • Take bias frames
  • Take 30 minutes each of R, G, and B on B33 area, binned 2×2, using 6×5-minute subs
    • Do the colours separately, focusing with each filter
    • Red
      • Focused
      • 3 10-minute subs
    • Green
    • Blue
    • Luminance
  • Take 90 minutes of luminance, unbinned, using 10-minute subs

Temp is -13 at 7:49 PM.

Thought it was clouding over, but it cleared again.

Very cold on the fingers.  Mount collision, had to re-synch a couple of times until I was quite cold.  Came inside to do focus and guiding setup.

Ruined a 10-minute Red by forgetting to set Filter in the auto-save tab. Don’t know what it took, but I got a blank image.  Then got one 5-minute Red sub, then guiding died – erratic image on guider, strange movements.  I think the scope may have stalled or hit a limit when I wasn’t there to notice the message, because it wouldn’t go to CWD home position later when I asked it to.

-18 to -20 on the thermometer in the dome.

Too cold – equipment not happy, making stupid mistakes.  I think I’m done until warmer weather arrives.  Maybe -10 as a limit.

Other lesson learned: do data gathering shots first, calibration later.  Tonight I got an hour of darks and no data.  Data and no darks would have been better.

Battery dead in red dot finder, flickering on flat frame box. Neither work well this cold.

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