Friday, August 9, 2013

My God, It's Full of Stars!

A couple sayings seem appropriate for this post.  The first is that you gotta' "Make Hay While The Sun Shines".  In other words, if the weather is good, and you've got hay cut, put off the trip to town and bale your hay before tomorrow's storm ruins the crop.  Farmers say it, really!  The other that comes to mind is that "I'd rather be lucky than good", and the picture at left seems to prove that!

We're back in Arizona now and we find a break in the monsoon clouds, so after getting Melinda safely off to work last night, I headed up to Kitt Peak National Observatory for some photon collecting..  While checking weather conditions, I normally check Heavens-Above to see about satellites, and notice a rather faint Iridium Flare is better if you go west (towards Kitt Peak).  Switching to the Observatory for the observing condition, the flare is predicted to be -8.4, which is about as bright as they get and about 80 times the brilliance of Venus!  What makes it more interesting is that it happens a few degrees from the deep-sky object M27, the "Dumbbell Nebula".  I usually enjoy imaging flares near sky objects, have posted one or two in the past.  Leaving home in Tucson, I had almost 2 hours to flare - you can set your watch by these, so you can't be late!

No stops for gas, snacks or bathroom, I took the required 80 minutes to legally make the trip and parked in the public lot.  One of the perks of working there - no one would have hassled me setting up there, but no one even checked on me, though one or two of the observatory cars passed in the deep twilight.  It was an incredibly clear night - it had been 2 months since the Canyon star party that I've seen skies like this.  Driving up the western flank of the mountain, the skinniest crescent moon hung on the horizon, yet as clear as overhead it was so clear.  As I set up my new Polarie tracking platform and hooked it up, I still had 10 or so minutes to go.  Camera, telephoto lens, polar align the tracker, install camera, focus on star - PERFECT!  Went to the field, between Delphinius and Cygnus, check camera settings, turn on long-exposure noise reduction for this exposure.  Check the clock - still a couple minutes for a test exposure...  Push the shutter - nothing!  Drat, I know exactly what it is - I forgot to switch the telephoto lens to manual focus, so in the dark, it tried, but couldn't find anything to focus on!  And of course, it moved it off the perfect focus I had set...So, back to a brighter star, live view, focus star, reacquire field in the viewfinder...  Check the clock - do I have time to take a test frame?  No!  Get out the intervalometer, preset to 3 minutes exposure.  Look up - I see a satellite!  Moving towards the field, I think it has to brighten a lot to be the flare, but in a few seconds, I push the button...  Off to the left, suddenly I see the REAL Iridium satellite flare to its brilliant peak - I was watching the wrong satellite!  I wanted to catch some details of the Milky Way and M27 if they were even in the frame, so let it go 2.5 minutes before I finally chickened out and viola - the picture seen above left!  Lucky, lucky, lucky!  The entire frame is shown, north is approximately towards upper right.  An annotated version of the frame is shown at right.  the two streaks are the satellites, the one marked with question marks is the mysterious one I was watching that caused me to start the exposure...

A friend once told me that "Luck Rewards The Well-Prepared", but in this case, I think I was lucky!

Of course, the above picture is re-sampled mightily to make the file a reasonable size, so lots of detail is lost.  Shown here at right at full camera resolution is the section over in Vulpecula (the Fox) where Messier 27, the Dumbbell Nebula is located.  I usually find it (can be spotted in binoculars!) by the faint parallelogram of stars connected in the image.  The greenish disk just below the bottom point is the nebula.  Don't forget that the 70-200 Canon F/2.8 zoom was set to 70mm for a wide field, so few details can be seen other than it's overall shape and color, but still nice to see next to the flare.

While setting up in the twilight, there was sort of a blustery breeze, which I sort of forgot about in my haste to get going.  But it did affect the image.  Lost in the above low-resolution image, the wind was wiggling the camera enough to reveal its presence.  In the full-res image at left you can see the wind-induced wiggles.  While easily seen in the trail of Iridium 75, the wiggle can't be seen in the stars' images, but it does manifest itself by bloating the star images a little bit...

So this is just the first frame of nearly 2GB of data I took on the incredible evening!  The rest I'll save for a subsequent post.  And I was still home by 1:30 - not bad for a "school night"!

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