Wednesday, August 23, 2017

#106 - Monday, August 21, 2017 - Total Eclipse of the Sun


So I am one of those people for whom capturing a moment on camera is of equal importance to actually seeing it.  The eclipse was jaw-dropping, heart-thumping, and incredible, but the moment at sticks out most clearly in my mind from the entire event was hitting the "review" button on my camera and seeing the images that I had captured.  An indescribable joy overtook me, and I could barely contain my excitement at how perfect they were.  All of the dreaming, scheming, script-writing, practice rounds, and hair-pulling in the months prior all paid off in that single moment when I saw the result of my labor.  But let me start first that morning so I can describe to you how it all went down!

My compatriot Sarah and I woke up at 6 AM and quickly finished packing our bags, checked out of the hotel, and grabbed a quick bite from the hotel continental breakfast.  We swung by Starbucks because I have a great need for coffee, but the line was very long, so we went to a grocery store instead and I just grabbed a bottle of coffee from the refrigerated drinks section.  We hurried over to one of the ASTROCON observing locations - the Summit Medical Center in Casper, WY.  It was only a few miles from the hotel, and there was not much traffic, thank goodness.  The Summit Medical Center was most gracious for letting us use their space - they let us come in to use the bathrooms and fill up on water and coffee, they turned off the sprinklers and the parking lot lights, brought out trash cans, had a security guard on site, and they covered the exterior lights of the building with surgical caps.  They even turned off the sprinklers a few days prior so the ground would be firm and dry for us to set up our gear.  It was fantastic!  We staked out our spot and started getting set up.

I attached my Nikon D5300 DSLR to my Borg 76mm ED refractor (via a Hotech SCA field flattener), and put the whole thing on my Celestron NexStar alt-az mount, powered by my 17 Ah power tank.  I used BackyardNikon to run the partial phase and totality scripts in serial cable mode (which takes frames every 2.5 seconds, instead of every 3.5 seconds that a USB connection does.  It's the same cable, it just talks to it differently).  I also ran my digital thermometer to record how the temperature changed.

At 10:22 AM, we had first contact!  It took another minute or two before you could see the shadow in the eclipse glasses.  I started my partial phases script a few minutes before.  However, I noticed that the images were triggering slow instead of fast, so I closed and reopened BackyardNikon.  Of course, one of my fears happened - BYN wanted to authenticate!  It does this occasionally, and it is extremely annoying, seeing as how it's a one-time fee for the software, not a subscription, and I don't always have internet access out on the observing field.  Luckily, the medical center also had open wifi, so I didn't have to fight cellular data traffic by tethering to my phone.  I got the script re-started, and it was triggering fast, thank goodness.  But a few minutes later, my other worst fear happened - my tablet randomly shut down!  Luckily, it was still near the beginning of the partial phase - I still had over an hour to get everything running.  I was glad this all happened with plenty of time to spare.  I got the tablet restarted, and I moved my telescope case with the lid open up onto the table to provide some shade for my tablet.  This seemed to help, and I got it restarted quickly.  Then, all we could do was wait.  We wandered around and looked through people's scopes, and I got a timelapse set up on my other DSLR.

As the moon covered more and more of the sun, the temperature began to drop, and the quality of the light changed.  It looked weaker, kind of more blueish-gray, like it was going behind a cloud but without the shadow.  Slowly, inexorably, the moon slid across the glowing surface of the sun, consuming it.  The Solar Eclipse Timer app on my phone announced the five minute warning, and I started recording a video on my phone, which I'd attached to one of my tripods, and then I went over to my tablet to get ready to switch scripts.  Two minutes.  My heart began to pound.  With shaking hands, I stopped the partial phase script and loaded the totality script.  One minute.  I hit the Start button on the totality script.  The darkness was coming fast now, the sun a tiny sliver.  My heart was beating so fast I felt weak and light.  Thirty seconds.  My hand was poised over the solar filter, ready to remove it.  Twenty seconds - off came the filter.  Then, all at once, darkness fell.  Cheers and shouts went up, and then the crowd fell quiet.  I removed my solar glasses and gazed in wonder at how such a sight was possible - a perfectly round, perfectly flat disk, encircled with a ring of white light, surrounded by a tenuous white glow that extended out in all directions.  Near the bottom of the glowing black disk, two brighter rays stretched out, magnetic fields lines in the corona.  Some high clouds drifted over, but could not diminish the light.  Time seemed to stretch and contract at the same time.  My phone announced that we had reached maximum eclipse, and reminded me to look around at the horizon.  I went over to my phone and panned around so I could capture it.  Sunset red and orange glowed in every direction.  The blue of the sky slid from light blue to dark blue to nearly black as I moved my eyes up the dome of the sky to the black sun.  I wished I had pulled out my binoculars so I could get a closer look, and I thought about going over to someone's telescope, but I didn't want to miss a single moment.  I stared up into the sky and burned the image into my memory.  People clapped and cheered, ooh'd and ahh'd.  "Glasses on, glasses on!" my phone announced.  I ignored its message - I wanted to see the sun re-emerge!  Westward, the sky was lightening.  Suddenly, a bright flash occurred as the sun began to return.  It was incredibly beautiful.  I put my solar glasses back on and watched the crescent rapidly increase in size.  I looked away and began to wander around in random directions.  What do I do now? I wondered.  I didn't know what to do with my hands, or where to look, so what to say.  I walked over to my camera to see how the pictures came out, and I saw a bright light on my hand - I forgot to put the solar filter back on!  I grabbed it quickly and slid it back over the end of the telescope.  Then I opened up the screen and started scrolling backwards through the extremely bright pictures at the end of the sequence.  I got back to the ones just after third contact, and I nearly fell over.  They were incredible!  The diamond ring, Bailey's beads, the chromosphere, the corona, every picture was more amazing than the last.  I had done it!  I had captured the solar eclipse with my camera!  I shouted for Sarah to come over to look.  Before long, I had a small crowd hunched over to look at my swiveled screen.  I jumped up and down a few times.  I couldn't believe it!

All right, I won't keep you waiting - here are a few of my favorites:
Partial phase - 1/2500s, ISO-200, Baader solar filter

Thin sliver - 1/2500s, ISO-200

Second contact diamond ring - 1/2000s, ISO-200

Corona (with some reflection off the thin high clouds) - 1/15s, ISO-200

Chromosphere and prominences - 1/2000s, ISO-200

Bailey's Beads - 1/2500s, ISO-200

Third contact diamond ring - 1/2500s, ISO-200

WOWEE WOW WOW!!  I can't get these pictures out of my head.  I get excited even thinking about them!  I am absolutely floored that I was able to do this.  

My next step now is to make a composite of the corona.  All of those solar eclipse corona images where you can see the moon and all the detail of the corona are carefully-constructed composites of multiple exposures that capture different parts of the corona - it's impossible to get the brighter center and the much much dimmer outer regions in the same exposure.  I've never done it before, so we'll see how this goes!

After totality, most people around me started packing up to try and beat the traffic, but I had planned on imaging the whole thing.  So I did what packing up I could while the moon continued to recede, and had some lunch of BBQ'd hamburgers.  After fourth contact, we got packed up, and I had the opportunity to thank the medical center administrator for letting us use the space.  Then we loaded the car, hopped in, and joined the Great American Traffic Jam.  I-25 was a disaster - there were several times where we were stopped long enough that I actually put the car in park.  We stopped in the town of Glendo along the way to use the bathroom (porta-potties had been set up there), and thank goodness I'd filled up the tank the night before because the gas station was absolutely packed.  My car has auto start-stop, so I was able to go for about 5 hours before even hitting 3/4 full tank.  We finally made it to US-26, and nearly all of the traffic on I-25 was from Colorado, so after that, the roadways were quite clear and the gas stations empty.  But it had taken us 6 hours to make it 100 miles, so we didn't get to our hotel in Kearney, NE until about 3 AM.  We nabbed about 5-1/2 hours of sleep, and then drove another full day back home.  It was a long and exhausting drive, but we got back safely.  While we were driving, moments from the eclipse kept popping back into my mind, mainly seeing the sun totally blocked out, and seeing my images right afterwards.

Big shoutout to Sarah for being an awesome travel companion, and WOW the eclipse was awesome!  You'll find me somewhere in the path of totality on April 8, 2024!

Other Eclipse Phenomena


The temperature drop was a neat phenomenon - after restarting my computer, the first recorded temperature is at 10:50 AM, and it was 86 degrees.  I realized later that the probe was in the sun, so I moved it to the shade, and it recorded a probably more accurate temperature of 75 degrees.  In 30-second intervals, I captured the temperature up until 1:17 PM, after fourth contact.  The lowest it reached was 60.8 degrees, which was actually 7 minutes after totality.
Some clouds came in around 12:25, and it was enough to drastically dim my partial phase images by 12:40, which contributed to the decline in temperature near the end.  I think the temperature dropped more slowly before totality than it rose after totality because the day was still warming up before totality.  Neat stuff!

Pinhole Projection

When the sun passes through a small opening, you can see an image of it through that opening.  Normally we don't pay much attention - of course light going through a round hole is going to make a circle.  But when the sun is partially eclipsed, you can see that shape through small holes instead.  
Leaves on trees also make good pinhole projectors - as the sun filters through them, you can see little crescent suns on the ground in the shadow of the tree.

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