Sunday, December 17, 2017

#121 - Saturday, December 16, 2017 - ♫You Gotta Know When to Fold 'Em♪

Finally, after several weeks of cloudy nights and clear, moonlit nights, a clear, dark night descended upon the observatory.  Four out of five of my forecasts promised clear skies, and ClearDarkSky said 4/5 on transparency (an important measure for if there will be thin, high clouds, which most forecasts don't count as clouds).  And it would be above freezing to boot!  With my D5300 back in hand after getting it repaired at Nikon (see the end of this post), and armed with my new Astronomik LRGB filters for my borrowed SBIG ST-8300M, I headed out late to the observatory after a Girl Scout meeting (I'm a troop leader for a few high schoolers).

From my co-leader's house, I followed Google's directions for the quickest route, which of course were fraught with peril.  It brought me a way I go sometimes, but had me turn on a road after the one I usually turned on - but I decided to see it through to see if it was really faster.  Well, after totally missing the minuscule turn, I turned around in the town just up the road, which was an adventure in itself because the streets were lined with cars and people for some kind of event.  The road it was having me turn down was the road to the Boy Scout camp that is adjacent to the state park, and I hit a dead end.  Now, there may have been a road through the camp that hooked back up with the road I use to get to the observatory, but I didn't necessarily want to drive through the middle of the camp in the middle of the night, so I whipped around and headed back the way I knew.  All in all, I finally pulled into the observatory parking lot at 8 PM.

I missed imaging the Christmas Tree nebula last year, and since I got out there so late, it was already just high enough to start imaging.  After setting up and focusing (and checking that my new filters were, in fact, parfocal - yay!), I started guiding, looked like crap.  I have about 50/50 luck with the Losmandy Gemini II mount that is in the memorial dome in it guiding well - sometimes it is spot-on, seeing-limited perfect, and sometimes it just decides to go visit Crazy Town.  (To be honest, it may not even be the mount, but weirdness with PHD - sometimes if I power down and restart everything, it works great).  After re-focusing the guide scope and trying again, it was still bad, so I gave up and slewed to a different target that was way up high and had already crossed the meridian - the Pacman Nebula, NGC 281, which I got luminance data for last time I was out.  I set it to take a 5-minute exposure on the red filter, and then went to go set up my DSLR on my Vixen Polarie star tracker.

When I came back to check on the test frame, it was super out of focus!  Once again, the focuser on that scope had slipped out, which was a result of me forgetting to tighten the screw on the focuser when I had focused earlier.  So I re-focused on star Caph in Cassiopeia, then drove back over to the Pacman Nebula and re-centered it using the Focus tool in CCDOps (which basically takes back-to-back, low-resolution images for focusing and centering targets - most nebulae have some kind of open cluster affiliated with them that is easy to see in this mode), and then started acquiring 5-minute frames in Sequence Generator Pro.  Finally, I was off to the races!

...almost.  I came back to check on the first two frames, and I had left the Bahtinov mask on...
This is what happens when you start imaging your target with the focusing mask still on the end of the telescope.

So after re-starting my red frames, I set up my DSLR on my Vixen Polarie.  The Vixen Polarie is a little device about the size of a large point-and-shoot camera and attaches to a regular camera tripod.  It's got a little 360-degree rotating head on top to attach your DSLR to, and a boresight hole in the side to sight Polaris through to roughly polar align it.  Then you simply turn the dial to the sidereal tracking rate, and it slowly rotates the camera at sidereal speed for imaging wide-field targets.  It's more well-suited to short focal length, short exposure images, and the rough polar alignment doesn't work that great (there is a $200 polar alignment module available, but that will have to wait till later).  I aimed my camera with a 55-200mm lens set at roughly 135mm at the Orion Molecular Complex area (including the Orion Nebula and Orion's Belt), figured out that 90 seconds was as long as I could do without trailing at that focal length on the Polarie, checked on the telescope one more time, and then finally went inside to eat dinner around 10 PM.

I brought some Southwest beef & bell pepper skillet with me (yup, ripped directly off the back of Kraft Colby & Monterey Jack cheese) (and it's delicious by the way) in a tupperware, and threw it in the microwave, plugged it in and...nada.  The readout was backlit, but none of the buttons worked, the light didn't come on, etc.  Then I remembered the last time I was out there, I reported that the microwave wasn't working, and that maybe the outlet was dead.  Nope.  No hot dinner for Molly.  Then I got an idea...the club has a few dew zappers in the dome room (known to the rest of the world as "hair dryers"), so I went and grabbed one of those.
Desperate times call for desperate measures!

It worked okay - by the time the top was nice and toasty, the lower layer would be back to room temperature, so I finally gave up after about 10 minutes and just ate it lukewarm.  

By the time I was done eating, it was time to go switch to the green filter (I was doing just 7x300s for each color channel so I could still get to bed at a reasonable hour), but some thin, high clouds had rolled in (in fact, two of my compatriots came out to watch the tail end of the Geminids meteor shower, and they had already left as a result).  Given everything else that wasn't going well that night, I decided it was time to call it quits around 10:30 PM.  It was a shame - not that cold, no wind to speak of, and wintertime targets rising.  Oh well, here's hoping for another chance this week before the moon starts encroaching on my first-half-of-the-night hours.

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